Editing Google Summer of Code/Project Ideas

If you want to work on '''computer-aided design (CAD), geometry, or graphics''', you've come to the right place!  Help us improve open source CAD.

Well prepared proposals from capable students have an ''outstanding'' chance of getting selected.  We consider proposals for all skill levels ranging from simple to crazy hard and everything in between.  [https://lists.sourceforge.net/lists/listinfo/brlcad-devel Introduce yourself], and we'll help you plan one right for you.

Remember that project descriptions are just ''initial ideas''.  You must expand with [[Summer_of_Code/Application_Guidelines|considerably more detail]].  Change the goals to fit your experience and interests.  See our '''[[Summer_of_Code/Checklist|checklist]]''' to get started.

This year, BRL-CAD is coordinating with five other communities that will get 1-2 students each to help bridge our work and encourage collaboration.  Projects that help exchange data or share code are desired!

{|-
 |align="center" width="15%"|[http://brlcad.org/w/index.php?title=Google_Summer_of_Code/Project_Ideas#BRL-CAD_Projects http://brlcad.org/images/logo/cutout_sticker_256.png]
 |align="center" width="15%"|[http://brlcad.org/w/index.php?title=Google_Summer_of_Code/Project_Ideas#OpenSCAD_Projects http://www.openscad.org/assets/img/logo.png]
 |align="center" width="15%"|[http://brlcad.org/w/index.php?title=Google_Summer_of_Code/Project_Ideas#LibreCAD_Projects http://librecad.org/files/live/sites/lc/files/WebImages/LogoLibrecad_logo.png]
 |-
 |align="center"|'''BRL-CAD''': 3D solid modeling, geometry processing, and robust high-performance ray tracing.  Help us make a better CAD system.  
 |align="center"|'''OpenSCAD''': rich syntax, programmable geometry.  Lots of possibilities to make it interoperate with BRL-CAD and LibreCAD.
 |align="center"|'''LibreCAD''': specializes in 2D CAD modeling, drafting, drawings.  Help build a bridge to BRL-CAD or add STEP support.
 |-
 |align="center" width="15%"|[http://brlcad.org/w/index.php?title=Google_Summer_of_Code/Project_Ideas#STEPcode_Projects http://stepcode.org/STEPcode_logo_gears_light.png]
 |align="center" width="15%"|[http://brlcad.org/w/index.php?title=Google_Summer_of_Code/Project_Ideas#Slic3r_Projects https://raw.githubusercontent.com/alexrj/Slic3r/master/var/Slic3r_128px.png]
|align="center" width="15%"|[http://brlcad.org/w/index.php?title=Google_Summer_of_Code/Project_Ideas#FreeCAD_Projects http://www.freecadweb.org/images/logo.png]
 |-
 |align="center"|'''STEPcode''': file format on steroids, STEP is a complex standard for geometry used by nearly every pro CAD system.
 |align="center"|'''Slic3r''': toolpath/G-code generator for 3D printers.
 |align="center"|'''FreeCAD''': parametric 3D modelling with strong Python interface and general engineering functionality like FEM and CAM 
 |}

'''Project titles link to a page with more details.'''

= BRL-CAD Projects =
== High Priority Topics ==
This year, we are most interested in topics that will immediately benefit BRL-CAD users.  Please align your proposal with one of the following three focus areas.  Talk with us at http://brlcad.zulipchat.com

{| bgcolor=#fff width=100%
|-
|align=center width=20% bgcolor=#e22|'''Performance'''
|bgcolor=#aaa|Faster geometry.  In order, ideas like'''[[Coherent Raytracing]]''', anything involving OpenCL, parallelizing serial code, and eliminating LIBBU pointer aliasing.
|-
|align=center width=20% bgcolor=#2e2|'''User Interface'''
|bgcolor=#ccc|Build on Google Code-In progress (OpenSCAD-style GUI), [[Convert MGED from Tk to Qt]], revamp our [[Overlap tool]] GUI, etc.  Qt and ray tracing are fair game.
|-
|align=center width=20% bgcolor=#22e|'''Core Infrastructure'''
|bgcolor=#aaa|Integrate appleseed rendering, extend and deploy Online Geometry Viewer (OGV), expand our geometry conversion (GCV) library.
|}

== Web Development ==

{| bgcolor=#fff
!
!align=center|Languages
!align=center|Difficulty
!align=center|Contacts
|-
|width=62%|'''[[Benchmark Performance Database]]:'''  BRL-CAD's Benchmark has been used for two decades to compare performance  across configurations.  Build a database website. 
|Depends (likely PHP or Python)
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison]]
|-
|width=62%|'''[[Synchronize Wiki with Docbook]]:'''  We use Docbook for most of our user documentation but find editing a wiki page much easier to use.  Set up a system so the two are always in sync.
|Depends (likely PHP or Python)
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Yapp]]
|-
|width=62%|'''[[Online Geometry Viewer Interface]]:'''  Continuation of existing work, improve our interface for viewing geometry online.  Focus on the front-end usability.
|Javascript, Meteor.js, Three.js, HTML, CSS
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison]]
|-
|width=62%|'''[[Online Geometry Viewer Back-end]]:'''  Continuation of existing work, improve our interface for viewing geometry online.  Focus on the back-end infrastructure.
|C++, Javascript, Meteor.js, Three.js
|align=center|HARD
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison]]
|-
|width=62%|'''[[Mediawiki 3D Geometry Extension]]:'''  Write an extension for Mediawiki that will visualize our .g files.  Maybe leverage LLVM C->Javascript translation. 
|Depends (likely PHP or Python)
|align=center|HARD
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison]]
|-
|width=62%|'''[[Materials Database]]:'''  Create a Materials Database web site for collecting, managing, and providing programmatic interfaces to material properties.
|Depends (likely PHP or Python)
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison, Yapp]]
|}

== Geometry ==

{| bgcolor=#fff width=100%
!
!align=center|Languages
!align=center|Difficulty
!align=center|Contacts
|-
|align=left width=62%|'''[[NURBS Editing Support]]:'''  BRL-CAD doesn't currently have support for editing NURBS primitives.  Fix that.
|align=center|C/Tcl
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Yapp]]
|-
|width=62%|'''[[Overlap tool]]:''' Resolving geometric interferences (aka overlaps) is a common geometry editing activity.  Design an awesome GUI for resolving conflicts.
|align=center|Tcl
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Yapp, Morrison, Greenwald]]
|-
|align=left width=62%|'''[[Vector Drawings from NURBS]]:'''  Huge impact here if you can update one or more of our raytracers to provide vector output instead of raster.  Perhaps render directly to PDF or SVG.
|align=center|C and/or C++
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Rossberg]]
|-
|width=62%|'''[[NMG Editing]]:'''  Our structured polygonal mesh geometry (N-Manifold Geometry = NMG) is a common export format, but our NMG edit support is non-existent.  We need something.
|align=center|C
|align=center|HARD
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison, Rossberg]]
|-
|width=62%|'''[[Visualizing Constructive Solid Geometry (CSG)]]:'''  CSG forms a directed acyclic graph.  Tree view widgets show a simple hierarchical representation, but we need something better.
|align=center|C/C++
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison]]
|-
|align=left width=62%|'''[[Plate Mode NURBS raytracing]]:'''  Imported NURBS geometry often does NOT enclose space (i.e., not solid), so add support for specifying an implicit thickness.
|align=center|C/C++
|align=center|HARD
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison]]
|-
|width=62%|'''[[STEP exporter]]:'''  We have an importer, we need a comprehensive exporter with support for implicit CSG, NURBS, or polygonal mesh geometry.
|align=center|C/C++
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Yapp, Morrison]]
|-
|width=62%|'''[[STEP importer improvements]]:'''  We have an importer, but it's preliminary.  Add support for importing hierarchy information, polygonal geometry, and implicit geometry.
|align=center|C/C++
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Yapp]]
|- 
|width=62%|'''[[STEP AP 242 Parser]]:'''  We already parse a subset of AP203, but the new kid on the block is AP242.  Make AP242 work with BRL-CAD's step-g importer. 
|align=center|C++
|align=center|HARD
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Mark, Charlie, Yapp, Kamga]]
|-
|width=62%|'''[[Convert BoT to Pipe]]:'''  Command line interface to convert facetted fluid/electrical line geometry into BRL-CAD native pipe solids.
|align=center|C/C++/Tcl
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison]]
|-
|width=62%|'''[[IGES import improvements]]:'''  We have extensive support for the International Geometry Exchange Standard (IGES) with our g-iges and iges-g converters, but they need updating.
|align=center|C
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison]]
|-
|width=62%|'''[[Geometry Conversion Library]]:'''  Probably our biggest open source asset is our extensive collection of importers and exporters.  Turn them all into a universal conversion library. 
|align=center|C/C++
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Greenwald, Morrison, Rossberg]]
|-
|width=62%|'''[[COLLADA Importer]]:'''  Create an importer for the COLLADA file format.
|align=center|C/C++
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison]]
|-
|width=62%|'''[[X3D Importer]]:'''  Create an importer for the X3D file format.
|align=center|C/C++
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison, Kamga]]
|-
|width=62%|'''[[OpenSCAD Importer]]:'''  Create an importer for OpenSCAD's format.
|align=center|C/C++
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison]]
|-
|width=62%|'''[[OpenSCAD Exporter]]:'''  Create an exporter for OpenSCAD's format.
|align=center|C/C++
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison]]
|-
|width=62%|'''[[Python Geometry]]:'''  Wrap BRL-CAD's primitives in Python, make it easier to script geometry creation. 
|align=center|Python
|align=center|Easy
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison]]
|-
|width=62%|'''[[Perl Geometry]]:'''  Wrap BRL-CAD's primitives in Perl, make it easier to script geometry creation. 
|align=center|Perl
|align=center|Easy
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Browder]]
|}

== Performance & Quality ==

{| bgcolor=#fff
!
!align=center|Languages
!align=center|Difficulty
!align=center|Contacts
|-
|align=left width=62%|'''[[OpenCL GPGPU Raytracing]]:''' We have about a dozen simple primitives that need to have a ray-object intersection function converted from C to OpenCL.
|align=center|C/OpenCL
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison]]
|-
|align=left width=62%|'''[[OpenCL GPGPU Complex Raytracing]]:''' We have about half a dozen complex primitives that need to have a ray-object intersection function converted from C to OpenCL.
|align=center|C/OpenCL
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison]]
|-
|align=left width=62%|'''[[OpenCL GPGPU Spatial Partitioning Raytracing]]:''' We use a Bounding Volume Hierarchy (BVH) to reduce the amount of intersections we need to compute to render an image. We need to replace this with a Kd-tree in order to be able to early terminate a render in models with high depth complexity. This should speed up render speed significantly for those models (e.g. Goliath).
|align=center|C/OpenCL
|align=center|HARD
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison]]
|-
|align=left width=62%|'''[[Coherent Raytracing]]:''' Our current raytrace pipeline dispatches and processes one ray at a time.  Send bundles and convert the pipeline into phases. 
|align=center|C/C++
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison, Rossberg]]
|-
|align=left width=62%|'''[[NURBS Booleans]]:'''  We have NURBS surface-surface intersections working.  Now we're using them to create evaluated forms of our CSG geometry.  Make it more robust and faster.
|align=center|C/C++
|align=center|HARD
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Yapp, Rossberg]]
|-
|align=left width=62%|'''[[NURBS Optimization and Cleanup]]:'''  We have a fantastic implementation of NURBS evaluation but haven't gone back to clean up or speed it up.  Make it pretty and fast.
|align=center|C/C++
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Yapp, Morrison]]
|-
|width=62%|'''[[Fix Bugs]]:'''  We take pride in our breadth of functionality and time-tested stability.  We still have bugs.  Identify some and fix them!
|align=center|C
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Browder]]
|-
|width=62%|'''[[NMG Raytracing Performance Improvement]]:'''  BRL-CAD's structured mesh geometry (N-Manifold Geometry = NMG) needs some time in a profiler.  Malloc during raytracing is bad.
|align=center|C
|align=center|HARD
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison, Greenwald]]
|-
|width=62%|'''[[Mesh library cleanup]]:'''  BRL-CAD has an extensive n-manifold polygonal mesh library that needs some refactoring, testing, and optimization rework.
|align=center|C
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison, Rossberg]]
|-
|width=62%|'''[[Space Partitioning for Tessellation]]:'''  Technically an optimization task, make our geometry converters run an order of magnitude faster by using spatial partitioning during tessellation.
|align=center|C
|align=center|HARD
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Greenwald, Yapp, Morrison]]
|-
|width=62%|'''[[Code Reduction]]:'''  BRL-CAD is more than 1M lines of code.  Approximately 10% of that is duplication.  Help reduce that percentage.
|align=center|C
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Greenwald, Morrison]]
|-
|width=62%|'''[[Header Restructuring]]:'''  BRL-CAD has about two dozen libraries with a single header declaring the entire public API.  Break up those monster headers into modular sub-headers.
|align=center|C
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Greenwald, Morrison]]
|-
|width=62%|'''[[Faster Overlap Detection]]:'''  BRL-CAD has a 'gqa' tool that detects overlaps.  Implement a replacement using a better approach.
|align=center|C
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Greenwald, Morrison]]
|}

== Infrastructure ==

{| bgcolor=#fff
!
!align=center|Languages
!align=center|Difficulty
!align=center|Contacts
|-
|width=62%|'''[[New Cross-Platform 3D Display Manager]]:'''  BRL-CAD uses '''''display managers''''' for visualizing 3D geometry in a window.  We want one that uses a cross-platform toolkit such as Qt + OGRE.
|align=center|C/C++
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison]]
|-
|width=62%|'''[[New Cross-Platform 2D Framebuffer]]:'''  BRL-CAD uses '''''framebuffers''''' to display 2D imagery.   The merits of having a single interface for most platforms is self-evident.
|align=center|C/C++
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison, Yapp]]
|-
|width=62%|'''[[Advanced Sketch Primitive Editor]]:'''  BRL-CAD has a 2D sketch primitive, but our handling of editing sketches doesn't incorporate parametric constraints.  There are potentially applicable codes in the open source community we can leverage for this, or we can roll our own solution.
|align=center|C/C++
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Yapp]]
|-
|width=62%|'''[[Geometric Constraint Solver]]:'''  Our LIBPC parametric constraint library is the work-in-progress foundation of being able to validate and describe geometry relationships.
|align=center|C/C++
|align=center|HARD
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison]]
|-
|width=62%|'''[[MGED to Archer Command Migration]]:'''  Our next-generation editor (Archer) needs to have the same (700+) commands that are in MGED.  Help make our next CAD interface awesome.
|align=center|C and Tcl
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Yapp, Kamga]]
|-
|width=62%|'''[[General Tree Walker]]:'''  We have a half dozen or more functions that will traverse a geometry hierarchy in different ways.  There only needs to be one.
|align=center|C
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Greenwald, Yapp, Morrison]]
|-
|width=62%|'''[[Consolidate image processing]]:'''  We have 100+ image processing tools that independently read and write file data.  Needs much reuse love.
|align=center|C
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Greenwald, Daga]]
|-
|width=62%|'''[[GED Transactions]]:''' Migrating functionality from our MGED geometry editor into our LIBGED library provided excellent code reuse, but now we need transactions so that actions can be undone.
|align=center|C
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison, Daga]]
|-
|width=62%|'''[[Add exec option to search]]:'''  Our LIBGED library provides a ''search'' command very similar to the UNIX ''find'' command for scanning through geometry.  Implement the -exec option.
|align=center|C
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Yapp, Daga]]
|-
|width=62%|'''[[Geometry Selection Functionality]]:'''  Implement a new selection command that lets you temporarily group objects based on spatial, attribute, or geometric properties.
|align=center|C
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison]]
|-
|width=62%|'''[[Astronomical units]]:'''  We already go "big", but accurately modeling at a galactic scale redefines that notion...
|align=center|C
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison, Greenwald, Daga]]
|-
|width=62%|'''[[Object-oriented interfaces|Object-oriented C++ Geometry API]]:'''  Extend our C++ library which provides a simple interface to BRL-CAD's core functionality.  Kickstart start a new geometry kernel.
|align=center|C++
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Rossberg, Kamga]]
|-
|width=62%|'''[[Point Clouds]]:'''  BRL-CAD has a basic point cloud primitive.  Beef it up, make it faster, maybe integrate with the Point Cloud Library (PCL) for evaluation.
|align=center|C/C++
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Browder, Kamga]]
|-
|width=62%|'''[[Annotations]]:'''  Implement support for 2D annotations, labels that can be added to geometry.
|align=center|Perl
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Browder]]
|-
|width=62%|'''[[Python Bindings]]:'''  With or without SWIG, wrap BRL-CAD's command library API so you can issue our creation and editing commands from Python.
|align=center|Python
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison]]
|-
|width=62%|'''[[Perl Bindings]]:'''  With SWIG, wrap BRL-CAD's ray-tracing library API so you can issue calls to librt ray-tracing functions from Perl.
|align=center|Perl
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Browder, Daga]]
|}

== Rendering & Scientific Analysis ==

{| bgcolor=#fff
!
!align=center|Languages
!align=center|Difficulty
!align=center|Contacts
|-
|width=62%|'''[[Shader Enhancements]]:'''  We have a functioning custom shader system in BRL-CAD, but there are now folks that specialize and there's lot of room for improvements.
|align=center|C
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison, Greenwald]]
|-
|width=62%|'''[[Material and Shader Objects]]:'''  This one is a biggie but easy.  Implement new object entities for describing shaders and material properties, use them during ray tracing.
|align=center|C
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison]]
|-
|width=62%|'''[[GUI Integration of Analysis Tools]]:'''  There are a ''lot'' of visualization tools in BRL-CAD, but most aren't integrated with the GUI.  Visualizing directly within the GUI would improve usability.
|align=center|C
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Rossberg]]
|-
|width=62%|'''[[Generalized abstracted spacial partitioning capability]]:''' Need more be said?  If you're familiar with BSPs, KD trees, and grid structures, then this one is for you.
|align=center|C
|align=center|HARD
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Greenwald, Morrison]]
|-
|width=62%|'''[[High Dynamic Range Support]]:'''  We don't have displays supporting this yet, but that's never stopped us before.  Implement support for images with more than 8-bits per channel.
|align=center|C and/or C++
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Greenwald, Yapp]]
|-
|width=62%|'''[[Analysis Library]]:'''  There are various tools in BRL-CAD for calculating weights, moments of inertia, and more.  They're stand-alone applications.  Turn them into a library.
|align=center|C
|align=center|HARD
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Yapp, Morrison]]
|-
|width=62%|'''[[Celestial mechanics particle system]]:'''  Simulate solar systems and galaxies.
|align=center|C/C++
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Greenwald]]
|-
|width=62%|'''[[Non-vacuum gravity simulator]]:'''  Simulate falling to earth.
|align=center|C/C++
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Greenwald, Morrison, Yapp]]
|-
|width=62%|'''[[Polarization]]:'''  We already do multispectral ray tracing, but don't simulate polarization effects.  Implement ray splitting and filtering.
|align=center|C
|align=center|HARD
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison, Rossberg]]
|-
|width=62%|'''[[Density functions]]:'''  Accurately represent everything from atmosphere to bone.  Implement support for parametric density functions for homogenous materials.
|align=center|C
|align=center|HARD
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Rossberg, Morrison]]
|-
|width=62%|'''[[Bending light]]:'''  Think gravity wells and satellite cameras.
|align=center|C
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison]]
|-
|width=62%|'''[[Appleseed renderer integration]]:'''  Appleseed is rendering infrastructure used by the film industry to make pretty pictures.  Make it shoot rays at our native geometry with our ray trace library.
|align=center|C
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Morrison]]
|}

== <An Idea of Your Own> ==

Do you have an idea of your own?  Maybe you need [http://brlcad.org/~sean/ideas.html more ideas] to inspire you?  We're very open to areas of academic research, industry applications, and ideas that get you hooked on open source CAD development.

Requirements:

* Passion for the task being suggested

= OpenSCAD Projects =

[http://openscad.org OpenSCAD] is a parametric solid 3D modeling tool which uses a Domain Specific Language to specify designs as plain text. It is specifically designed with 3D printing in mind.

{| bgcolor=#fff width=100%
!
!align=center|Languages/Tools
!align=center|Difficulty
!align=center|Contacts
|-
|align=left width=62%|'''[https://github.com/openscad/openscad/wiki/Project%3A-Improve-DXF-import-and-export Improve DXF Import and Export]:''' Look into using an external library for DXF import (and export?).
|align=center|C++
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Marius/Torsten]]
|-
|align=left width=62%|'''[https://github.com/openscad/openscad/wiki/Ideas-for-Development-Tasks#openscad-standard-library OpenSCAD Standard Library]:''' Create a standard user-space OpenSCAD library.
|align=center|OpenSCAD
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Marius/Torsten]]
|-
|align=left width=62%|'''[https://github.com/openscad/openscad/wiki/Project%3A-Improve-OpenGL-rendering OpenGL framework]:''' Rewrite the OpenGL rendering code to use a rendering framework. Focus on compatibility with OpenGL ES2 and rendering performance.
|align=center|C++ OpenGL
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Marius/Torsten]]
|-
|align=left width=62%|'''[https://github.com/openscad/openscad/wiki/Ideas-for-Development-Tasks#persistant-caching Persistent Caching]:''' Implement a disk-based version of the internal memory caches
|align=center|C++
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Marius/Torsten]]
|-
|align=left width=62%|'''[https://github.com/openscad/openscad/wiki/Project%3A-Multi-threaded-geometry-rendering Multi-threaded Geometry Evaluation]:''' Implement multi-threaded evaluation of geometry.
|align=center|C++
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Marius/Torsten]]
|-
|align=left width=62%|'''[https://github.com/openscad/openscad/wiki/Project%3A-Survey-of-CSG-algorithms Survey of CSG algorithms]:''' Review existing research, evaluate and prototype algorithms.
|align=center|C++
|align=center|MEDIUM-HARD
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Marius/Torsten]]
|-
|align=left width=62%|'''[https://github.com/openscad/openscad/wiki/Project%3A-Add-support-for-exporting-models-in-STEP-format| Add support for exporting models in STEP format]:''' Enable better integration with other CAD tools by adding STEP export.
|align=center|C++
|align=center|HARD
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Marius/Torsten]]
|-
|align=left width=62%|'''[https://github.com/openscad/openscad/wiki/Ideas-for-Development-Tasks#issue-handling Issue Handling]:''' Day-to day issue and community management, fix incoming and existin issues. Good place to get started.
|align=center|C++
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Marius/Torsten]]
|-
|align=left width=62%|'''[https://github.com/openscad/openscad/wiki/Ideas-for-Development-Tasks#test-framework-improvements Test Framework Improvements]:''' Improve tests and test framework. Good place to get started.
|align=center|C++
|align=center|EASY-MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Marius/Torsten]]
|-
|align=left width=62%|'''[https://github.com/openscad/openscad/wiki/Ideas-for-Development-Tasks#svg-import SVG Import]:''' Improve/finalize SVG import.
|align=center|C++, SVG
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Marius/Torsten]]
|-
|align=left width=62%|'''[https://github.com/openscad/openscad/wiki/Ideas-for-Development-Tasks#larger-tasks-for-particularly-experienced-people Larger tasks for particularly experienced people]:''' Various harder tasks which are not fully specified and requires significant effort to design and implement.
|align=center|C++
|align=center|HARD
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Marius/Torsten]]
|}

The OpenSCAD team is also open to new ideas. Please [http://www.openscad.org/community.html get in touch] to discuss your ideas and convince a mentor to back it.

= LibreCAD Projects =

LibreCAD is a free Open Source CAD application for Windows, Apple and Linux. Support and documentation is free from our large, dedicated community of users, contributors and developers.
Please refer to [http://wiki.librecad.org/index.php/GSoC_2018#LibreCAD_Project_Ideas LibreCAD GSoC 2018 ideas] for more detailed description.


{| bgcolor=#fff
!
!align=center|Languages
!align=center|Difficulty
!align=center|Contacts
|-

|- bgcolor=#ffffff
|width=62%|'''[http://wiki.librecad.org/index.php/GSoC_2018#LibreCAD_Project_Ideas LibreCAD 3 UI]:'''  Add missing features, e.g. snapping, to the very basic GUI.
|align=center|C++,Math
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Armin]], [[Google_Summer_of_Code/Project_Ideas#Mentors|Florian]]
|-

|- bgcolor=#ffffff
|width=62%|'''[http://wiki.librecad.org/index.php/GSoC_2018#LibreCAD_Project_Ideas LibreCAD 3 DXF Entities]'''  Implement missing DXF entities, e.g. blocks, use LibreCAD 2 for reference.
|align=center|C++,Math
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Armin]], [[Google_Summer_of_Code/Project_Ideas#Mentors|Florian]]
|-


|- bgcolor=#ffffff
|width=62%|'''[http://wiki.librecad.org/index.php/GSoC_2018#LibreCAD_Project_Ideas LibreCAD 3 OpenGL rendering]:'''  Replace our current rendering engine ''Cairo'' with pure OpenGL rendering.
|align=center|C++
|align=center|MEDIUM/HIGH
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Armin]], [[Google_Summer_of_Code/Project_Ideas#Mentors|Florian]]
|-

|- bgcolor=#ffffff
|width=62%|'''[http://wiki.librecad.org/index.php/GSoC_2018#LibreCAD_Project_Ideas LibreCAD 3 Plugin Interface]'''  Right now we have some LUA based scripting support for LibreCAD 3. But we want to be much more extensible, e.g. with a XML/JSON interface.
|align=center|C++
|align=center|MEDIUM/HIGH
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Armin]], [[Google_Summer_of_Code/Project_Ideas#Mentors|Florian]]
|-

|- bgcolor=#ffffff
|width=62%|'''[http://wiki.librecad.org/index.php/GSoC_2018#LibreCAD_Project_Ideas LibreCAD 3 trimming support]'''  LibreCAD 3 trim operation doesn't support all entities  and is entirely written in Lua. We need a better system which would support all entities and divide operation. 
|align=center|C++,Math
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Armin]], [[Google_Summer_of_Code/Project_Ideas#Mentors|Florian]]
|-
|}

= STEPcode Projects =

{| bgcolor=#fff width=100%
!
!align=center|Languages
!align=center|Difficulty
!align=center|Contacts
|-
|width=62%|'''[[STEP Coverage Test]]:'''  Write a program that links against STEPcode and generates a STEP output instantiating every entity for a given schema.  Goal is a comprehensive program and data file for testing STEP import/export.
|ANY (C/C++, Python, Java, Perl, ...)
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Mark, Charlie]]
|- 
|width=62%|'''[[STEP Incremental Loading]]:''' Basically take a work-in-progress to the next level.  Modify the STEP parser to only read what it needs when it needs it, test, clean up, profile, and optimize.
|align=center|C++
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Mark, Charlie]]
|- 
|width=62%|'''[[STEP Minimal Examples]]:''' Create minimal examples for various schemas - such as AP214 or AP242 - in the style of [http://github.com/stepcode/stepcode/blob/master/example/ap203min/ap203min.cpp ap203min]
|align=center|C++
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Mark, Charlie]]
|- 
|width=62%|'''[[STEP Multiple Protocol Parsing]]:''' Currently creates a parser that works with a specific application protocol (e.g., AP203, AP214).  Make it work with multiple simultaneously. 
|align=center|C++
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Mark, Charlie]]
|- 
|width=62%|'''[[STEP Source Code Documentation]]:'''  We already use doxygen, but could do much better. Improve code documentation and utilize additional doxygen features such as topic pages. Add a 'make doxygen' target to invoke doxygen.
|align=center|C/C++
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Mark, Charlie]]
|-
|width=62%|'''[[STEP EXPRESS Documentation]]:'''  Write 'exp2html', similar to exp2py or exp2cxx (python and C++ generators) but outputs graphs and hyperlinked documentation with JavaScript search. Output will include EXPRESS comments (this requires modifying the parser).
|align=center|C/C++, JavaScript
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Mark, Charlie]]
|-
|width=62%|'''[[STEP Viewer]]:'''  STEP is a common CAD file format supported by just about every major CAD system.  Given we have an importer and an interface for displaying geometry, a stand-alone STEP file viewer has some great potential.
|align=center|C/C++
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Mark, Charlie]]
|-
|width=62%|'''[[STEP Code Refactoring]]:'''  Split large files and functions, add unit tests, move contents of LISTdo loops into separate functions.
|align=center|C/C++
|align=center|EASY
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Mark, Charlie]]
|-
|width=62%|'''[[STEP Thread Safety and Performance]]:'''  Modify the libraries to improve thread safety, increase performance using hotspot analysis
|align=center|C/C++
|align=center|MEDIUM
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Mark, Charlie]]
|}

= Slic3r Projects =

[http://slic3r.org Slic3r] is CAM desktop application for toolpath/G-code generation for 3D printers.

{| bgcolor=#fff width=100%
!
!align=center|Languages
!align=center|Difficulty
!align=center|Contacts
|-
|width=62%|'''Conditional G-code and arithmetic expressions parser:'''  Implement a grammar parser for conditional and arithmetic expressions within custom G-code, maybe using Boost.Spirit or some other library. [https://github.com/alexrj/Slic3r/issues/3390 #3390]
|C++
|align=center|Easy-Medium
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Alessandro/Joseph]]
|- 
|width=62%|'''Port the GUI to C++:''' The GUI is currently coded in Perl using wxWidgets and our goal is to have it ported to C++. The wxWidgets API is almost identical between Perl and C++, so it's an easy task. There are a couple things where we use the dynamic features of Perl which are trickier and interesting to port.
|C++/wxWidgets
|align=center|Easy
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Alessandro/Joseph]]
|-
|width=62%|'''Port the SVGNest library to C++:''' The SVGNest library provides an algorithm for polygon nesting. It's written in JavaScript and a C++ port of it would improve Slic3r's auto-arrange feature. [https://github.com/alexrj/Slic3r/issues/3237 #3237]
|C++
|align=center|Easy
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Alessandro/Joseph]]
|-
|width=62%|'''Fix bugs of the Boost.Voronoi library:''' The good but unmaintained Boost.Voronoi library has a couple minor issues affecting Slic3r's results. Interesting task for learning the Voronoi algorithm and how to troubleshoot a computational geometry issue. [https://github.com/alexrj/Slic3r/issues/2948 #2948]
|C++
|align=center|Medium
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Alessandro/Joseph]]
|-
|width=62%|'''Wireframe printing:''' Implement the wireframe printing algorithm. [https://github.com/alexrj/Slic3r/issues/2274 #2274]
|C++
|align=center|Medium
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Alessandro/Joseph]]
|-
|width=62%|'''Automatic part rotation:''' Automatically rotate a part to make some face of the part the bottom. [https://github.com/alexrj/Slic3r/issues/3047 #3047]
|C++
|align=center|Medium
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Alessandro/Joseph]]
|-
|width=62%|'''Manual support creation:''' Allow users to place and move support pillars by clicking in the 3D GUI. [https://github.com/alexrj/Slic3r/issues/3062 #3062]
|C++/Perl/OpenGL
|align=center|Medium/Hard
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Alessandro/Joseph]]
|-
|width=62%|'''Refactor the TriangleMesh class and support non-solid walls:''' Replace the internal mesh representation (currently based on admesh) using an existing 3D mesh library or implementing a half-edge structure; only use admesh for fixing models. Keep non-solid walls and slice them as single paths. Bonus: import SVG paths and position them freely using the GUI for printing as single extrusions. [https://github.com/alexrj/Slic3r/issues/3560 #3560] [https://github.com/alexrj/Slic3r/issues/3523 #3523]
|C++
|align=center|Medium/Hard
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Alessandro/Joseph]]
|-
|width=62%|'''Implement 3MF format read/write:''' Add the 3MF format for both reading and writing. [https://github.com/alexrj/Slic3r/issues/2811 #2811]
|C++
|align=center|Easy
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Alessandro/Joseph]]
|-
|width=62%|'''Non-planar printing:''' Implement techniques for non-planar printing. [https://github.com/alexrj/Slic3r/issues/3442 #3442]
|C++
|align=center|Medium
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Alessandro/Joseph]]
|-
|width=62%|'''Support surface colors and mixing extruders:''' Read surface colors from AMF or OBJ and keep them throughout the slicing process in order to generate G-code for mixing extruders. [https://github.com/alexrj/Slic3r/issues/3546 #3546]
|C++/Perl
|align=center|Hard
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Alessandro/Joseph]]
|-
|width=62%|'''Clean the libslic3r API and write bindings for it:''' Expose the internal algorithms of Slic3r as a library and write bindings for Python, Perl etc.
|C++/any
|align=center|Easy
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Alessandro/Joseph]]
|-
|width=62%|'''Write a Slic3r plugin for Grasshopper:''' Expose Slic3r functionality as many separate components that can be plugged in larger GH definitions (for example: slice a NURBS model in GH and feed the slices to the toolpath generation process in order to skip mesh generation, or provide flow calculation for people driving 5-axis robots with custom motion). This requires a fair amount of design work.
|C++
|align=center|Medium/Hard
|align=center|[[Google_Summer_of_Code/Project_Ideas#Mentors|Alessandro/Joseph]]
|}

= FreeCAD Projects =

{| bgcolor=#fff width=100%
!
! Language
! Difficulty
! Contact
|-
|width=62%|'''[http://www.freecadweb.org/wiki/Advanced_FreeCAD_test_system Advanced FreeCAD test system ]''': Create a framework for result file based comparisons and workbench specific comparators. Also creation of test cases should be simplified by a GUI or wizard.
|align=center|Python/C++
|align=center|Medium
|align=center|[http://forum.freecadweb.org/memberlist.php?mode=viewprofile&u=686 Ickby]
|-
|width=62%|'''[http://www.freecadweb.org/wiki/Topological_Naming_Project Topological Naming Project]''': Implementation of subshape identifiers based on creation history and update of topology class to work with those identifiers.
|align=center|C++
|align=center|Hard
|align=center|[http://forum.freecadweb.org/memberlist.php?mode=viewprofile&u=686 Ickby]
|-
|width=62%|'''[http://www.freecadweb.org/wiki/Direct_modeling_tools Direct modeling tools]''': Create a new layer of tools and objects, that work on top of existing Part-based 3D objects, that allow a user to graphically modify their geometry.
|align=center|Python/C++
|align=center|Medium
|align=center|[http://forum.freecadweb.org/memberlist.php?mode=viewprofile&u=68 Yorik]
|-
|width=62%|'''[http://www.freecadweb.org/wiki/FEM_Post_Processing_based_on_VTK FEM Post Processing based on VTK]''': Base the existing FEM VTK post processing on the updated SMESH data structure and design a python interface for it. Also improve integration into the workbench.
|align=center|C++
|align=center|Medium
|align=center|[http://forum.freecadweb.org/memberlist.php?mode=viewprofile&u=686 Ickby]
|-
|width=62%|'''[http://www.freecadweb.org/wiki/IPython_notebook_integration IPython notebook integration]''': Create a way to export the open inventor scenegraph as a JavaScript file and add functions for seamless interaction with the IPython display system
|align=center|C++, JavaScript, Python
|align=center|Easy
|align=center|[http://forum.freecadweb.org/memberlist.php?mode=viewprofile&u=686 Ickby]
|-
|width=62%|'''[https://www.freecadweb.org/wiki/Integrate_Cycles_renderer Integrate Cycles renderer]''': Add Blender's new Cycles renderer as a new render engine to the Raytracing Workbench
|align=center|C++
|align=center|Medium
|align=center|[http://forum.freecadweb.org/memberlist.php?mode=viewprofile&u=68 Yorik]
|-
|width=62%|Stepwise integration of ElmerFem into FreeCAD should be done in three phases:
Phase 1 - '''[https://www.freecadweb.org/wiki/New_solver_object_for_handling_ElmerFEM_execution_in_FEM-workbench New solver object for handling ElmerFEM execution in FEM-workbench]'''. 
Phase 2 - '''[https://www.freecadweb.org/wiki/Mapping_of_main_ElmerSolver_setting_for_mechanical_simulations Mapping of main ElmerSolver setting for mechanical simulations]'''. 
Phase 3 - '''[https://www.freecadweb.org/wiki/Give_graphical_access_to_a_wide_range_of_available_ElmerSolver_setting_from_within_FreeCAD Give graphical access to a wide range of available ElmerSolver setting from within FreeCAD]'''
|align=center|Python/C++
|align=center|Medium-Hard
|align=center|[https://forum.freecadweb.org/memberlist.php?mode=viewprofile&u=2069 Bernd], [https://forum.freecadweb.org/memberlist.php?mode=viewprofile&u=6222 HoWil]
|-
|width=62%|'''[https://www.freecadweb.org/wiki/PartDesign_Updates PartDesign Updates]''': Finish PartDesign port to new Body object, simplify the workflows and extend tools while making them more robust.
|align=center|C++, Python
|align=center|Medium
|align=center|[http://forum.freecadweb.org/memberlist.php?mode=viewprofile&u=686 Ickby]
|-
|width=62%|'''[https://www.freecadweb.org/wiki/GSoC_FEM_Solver_Z88 GSoC FEM Solver Z88]''': Extend the capabilities of FEM solver Z88OS in FreeCAD FEM workbench.
|align=center|Python
|align=center|Easy-Medium
|align=center|[http://forum.freecadweb.org/memberlist.php?mode=viewprofile&u=686 Bernd]
|-
|width=62%|'''[https://www.freecadweb.org/wiki/GSoC_FEM_Unit_Tests GSoC FEM Unit Tests]''': Extend the unit tests of FreeCAD FEM workbench.
|align=center|Python
|align=center|Easy-Medium
|align=center|[http://forum.freecadweb.org/memberlist.php?mode=viewprofile&u=686 Bernd]
|-
|width=62%|'''[https://www.freecadweb.org/wiki/GSoC_Path/Robot_Integration GSoC Path/Robot Integration]''': Path is the CNC/CAM workbench. It currently lacks any simulation capability. Robot workbench is a tool for simulating industrial robots. Extend Path and Robot workbenches to support simulation of CNC operations in the Robot workbench.
|align=center|C++, Python
|align=center|Easy-Medium
|align=center|[http://forum.freecadweb.org/memberlist.php?mode=viewprofile&u=68 Yorik], [https://forum.freecadweb.org/memberlist.php?mode=viewprofile&u=708 sliptonic]
|}

= Mentors =

BRL-CAD operates under group mentorship.  That means you can contact anyone, not just the person assigned to you, for assistance.  The mailing list and IRC channel are the preferred communication methods.

* Christopher Sean Morrison
** brlcad on irc.freenode.net
** Org admin, BRL-CAD open source project lead

* Erik Greenwald
** ``Erik on irc.freenode.net
** Org admin, BRL-CAD core dev

* Cliff Yapp
** starseeker on irc.freenode.net
** BRL-CAD Mentor, core dev

* Daniel Rossberg
** d_rossberg on irc.freenode.net
** BRL-CAD Mentor, core dev, math expert

* H.S. Rai
** hsrai on irc.freenode.net
** BRL-CAD Mentor, math expert

* Tom Browder
** BRL-CAD Mentor, analysis expert

* Bryan Bishop
** BRL-CAD Mentor, python guru

* Isaac Kamga
** Izakey on irc.freenode.net
** BRL-CAD Mentor, C/C++ Programmer

* Mohit Daga
** zero_level irc.freenode.net
** BRL-CAD Mentor, Computer Science Engineer

* Mark Pictor
** mpictor on irc.freenode.net
** STEPcode Mentor

* Charlie Stirk
** cstirk
** STEPcode Mentor

* Marius Kintel
** kintel on irc.freenode.net
** OpenSCAD Mentor

* Torsten Paul
** teepee on irc.freenode.net
** OpenSCAD Mentor

* Armin Stebich
** LordOfBikes on irc.freenode.net
** LibreCAD Mentor

* Florian Roméo
** Feragon on irc.freenode.net
** LibreCAD Mentor

* Alessandro Ranellucci
** Sound on irc.freenode.net
** Slic3r Mentor

* Joseph Lenox
** LoH on irc.freenode.net
** Slic3r Mentor