NURBS TODO

Optimize BREP/NURBS ray tracing

• Benefit: faster ray tracing runtime
• References:
  • src/librt/primitives/brep
  • src/librt/opennurbs_ext.*

Optimize BREP/NURBS prep

• Benefit: faster ray tracing runtime, user requested.
  • src/librt/primitives/brep/brep.cpp:rt_brep_prep()
  • src/librt/opennurbs_ext.*

Implicit-to-NURBS

Implement conversion of implicit primitives to BREP/NURBS primitives. Partially complete, primitives are fixed at origin, some primitives unimplemented.

• Benefit: partial requirement for interactive visualization of implicit CSG geometry in OpenGL.

BREP/NURBS-to-NMG

Implement conversion of BREP/NURBS to NMG.

• Benefit: partial requirement for export and interactive visualization of BREP/NURBS in OpenGL.

BSPLINE/NURBS review

Identify useful concepts implemented in the old BSPLINE/NURBS code that are not present in openNURBS.

• Benefit: code reuse, potentially very useful functionality.

BSPLINE/NURBS reuse

Port any useful BSPLINE/NURBS code to openNURBS data structures and routines.

• Benefit: code reduction, allows the old BSPLINE/NURBS code to be removed after functionality is migrated.

BREP/NURBS CSG evaluation

Implement boolean evaluation of BREP/NURBS surfaces.

• Benefit: partial requirement for interactive visualization of BREP/NURBS in OpenGL.

Plate-mode BREP/NURBS

Implement plate mode BREP/NURBS objects. Similar, if not identical, to plate mode BoTs, 'brep' objects need the ability to have a thickness described so you could automatically handle non-solid NURBS and sheet-metal style geometry without requiring surface solidity.

• Benefit: allows for import and visualization of BREP/NURBS surfaces that are not solid.

Implicit CSG to BREP/NURBS CSG test scripts

Develop test scripts for comparing conversion of implicit CSG to BREP/NURBS CSG

• Benefit: provides validation and verification via ray tracing.

BREP/NURBS documentation

Document the new BREP/NURBS primitive.

• Benefit: provides user documentation explaining capabilities, limitations, and benefits.

Cache objects

Implement data cache objects. Create new LIBRT API routines for storing cache data in a v5 container. This would amount to storing binary data into a 'binunif' object marked as hidden with attributes for date/time stamping and MD5 or SHA256 checksumming.

• Benefit: faster ray tracing runtime, applicable to other primitives (NMG, BoT).

Cache prep results

Cache BREP/NURBS prep results to a specified cache file.

• Benefit: faster ray tracing runtime for BREP/NURBS, user requested.

BREP/NURBS wireframe

Improve BREP/NURBS wireframe. Investigate using knots on subcurves.

• Benefit: faster wireframe, more detailed close wireframes.

BREP/NURBS source code cleanup

Consolidate Owens and Reeves approaches to ray intersection.

• Benefit: improved code maintainability.

Reference: http://www.cs.utah.edu/~shirley/papers/raynurbs.pdf

BREP/NURBS healing

Implement an rt_heal(rt_db_internal *dbi); routine. The routine tightens up trimming curves and edge/vertex pairings so that they align perfectly while still preserving the topological structure.