User:Phoenix/GSoc2012/Reports

From BRL-CAD
< User:Phoenix
Revision as of 22:14, 3 July 2012 by Phoenix (talk | contribs) (→‎Test Results)

Log

Community Bonding

  • May 2
    • Downloaded the source code of the latest revision from svn checkout and got more familiar with subversion.
    • Compiled and built the source both in Ubuntu and Windows (Visual Studio 2010) successfully.
  • May 13
    • Found and fixed a small bug in eto_brep (the rotation axis of eto is wrong), and submitted a patch on sourceforge.net.
  • May 15
    • Modified the eto_brep patch with the test case provided by Cliff.
  • May 16
    • Continued working on the conversion of eto.
    • Tested the brep conversion of hyp, but found the raytrace result of implicit CSG hyp quite strange.
  • May 17
    • The raytrace of implicit hyp is wrong when H is not perpendicular to A.
    • Fixed the conversion to brep of hyp (havn't commited yet).
  • May 18
    • My first SVN Commit: fixed the shearing direction of hyp.

Week 1

  • May 21
    • Fixed the bug of wrong id & od for pipe b-rep, by changing some prevp to curp.
    • Dealt with duplicated points by deleting them from the linklist.
  • May 22
    • Added some control to deal with special cases in pipe_brep.cpp and add a few comments.
  • May 23
    • Read and tried to understood the code in revolve_brep.cpp, but got confused by the implicit definition.
    • Changed the revolution axis and origin of the sketch plane of revolve_brep.
  • May 24
    • Changed the position of the sketch in extrude_brep according to the parameters.
    • Fixed the plane direction of circle arcs in sketch_brep as well as in revolve_brep.
  • May 25
    • Dealt with non-full revolution of revolve_brep. It took a long time to get the expected result, but I got more familiar to NURBS/BREP during that procedure.

Week 2

  • May 27
    • Tested and examined the implemented brep conversions. Checked the current status of my work.
  • May 28
    • Added the implicit -> brep conversion to conversion.sh, so that massive testing will be more convenient.
  • May 29
    • Tested the functionality of conversion.sh and brep conversions. Made a small change.
    • Modified brep.c in libged to check whether the conversion is successful.
  • May 30
    • Read the code in clone.c, and began to implement the temporary unevaluated conversion of comb in the brep command in MGED.
  • May 31
    • Extended the functionality of the brep command in MGED to deal with comb. Unevaluated breps are generated. More tests are needed.
  • June 1
    • The unevaluated conversion for comb has been implemented. Changed conversion.sh accordingly. And the whole elasped time for each object is evaluated.
    • Handled some exceptions in brep_debug.cpp.
    • Freed memories and corrected the "name existed" output in brep.c in libged.
  • June 2
    • Tested the brep conversion on ktank.g, m35.g, etc. with conversion.sh.
    • Modified brep_debug.cpp to deal with empty combs.

Week 3

  • June 3
    • Fixed the wrong malloc size and freed tmpname before returning in brep_debug.cpp.
  • June 4
    • Modified openNUBRS_ext.cpp to quell set-but-unused warnings.
    • Tested brep conversion of all /db/*.g files. Looked into the log to find out what to do next.
    • Found a bug in pipe_brep.cpp dealing with colinear points.
  • June 5
    • Modified pipe_brep.cpp. It's much better now, but problems still remain.
  • June 6
    • Fixed a concealed bug in pipe_brep.cpp. Now it works properly.
  • June 7
    • Fixed the destruction failure in pipe_brep.cpp by duplicating the curves.
  • June 8
    • Modified brep_debug.cpp to skip the conversion of half when converting a comb. The implicit primitive of half remains in the hierarchy.
    • Explored the usage of ON_BrepRegion to represent an infinite halfspace, but had no good luck.

Week 4

  • June 11 - June 18
    • Final examination week in our school.

Week 5

  • June 18
    • Final exams finished. Started to work!
    • Added pnts to the ignore list when converting a comb.
    • Modified the describe and ifree functions in pnts.c checking whether count==0 to avoid segmentation fault.
  • June 19
    • Corrected the wrong comments in arb8_brep.cpp and arbn_brep.cpp.
    • Add a brep conversion function to ars, which first converts it to an nmg and then to b-rep.
  • June 20
    • Use ft_brep functions for half and pnts, returning a NULL brep pointer, and check within brep_conversion() and brep_conversion_tree().
  • June 21
    • Tried implementing rt_part_brep() for primitive part. Things get much closer now after much tests and modifications.
  • June 22
    • Finished a raw version of brep conversion for part. Some special cases need to be considered later.
  • June 23
    • Enhanced some special cases (sphere) in part_brep.cpp.

Week 6

  • June 24
    • Fixed the wrong normal direction of the brep form of part.
  • June 25
    • Studied the primitive metaball. Found it quite hard to get started.
  • June 26
    • Studied the two papers Cliff provided on metaballs, but still cannot find the answer.
    • Copied the transformation matrix when converting the leaves in a tree. (Later adjusted to copying all data from the old tree first)
  • June 27
    • Evaluated the results and uploaded the screenshots to the log page. (See "Test Results")
    • Modified dsp_brep.cpp, using the dsp_stom matrix to do the transformation, instead of using the magic numbers.
  • June 28
    • Implemented a b-rep conversion function for superell.
  • June 29
    • Tested the results of conversion of superell. (See below)
  • June 30
    • Uploaded the raytracing results of superells with e or n > 2.

Week 7

  • July 2
    • Added conversion functions to cline. We first convert cline to an implicit pipe, and then convert the pipe to b-rep.
  • July 3
    • Modified superell_brep.cpp to generate multiple surfaces for superells with e or n > 2.
    • Uploaded images with the modified b-rep conversion routine for superell.
  • July 4
    • Uploaded images of the raytrace results of cline (both implicit and b-rep).
    • Fixed the wrong weight when the center (origin) is set to be control points.

Test Results

The brep conversion has been tested on several db/*.g files. Below are the screenshots of the raytrace results.

  • m35.g: component (left: implicit + csg, right: brep + csg)

M35.implicit.png M35.brep.png

  • ktank.g: tank (left: implicit + csg, right: brep + csg)

Ktank.implicit.png Ktank.brep.png

  • havoc.g: havoc (the raytrace of brep+csg takes a too long time, so the result hasn't been generated yet)
  • A DSP primitive with a 30*30 map: (left: implicit, right: brep)

Dsp implicit.png Dsp brep.png

Superell 0.8 0.2.png Superell 1.0 2.0.png

    • There is still some problems when n > 2 or e > 2. (left: n = 0.2, e = 3.0, right: n = e = 3.0)

Superell 0.2 3.0.png Superell 3.0 3.0.png

    • The problem above was fixed in r51405. (first: n = 0.2, e = 3.0, second: n = e = 3.0, third: n = 3.0, e = 0.2)

Superell 0.2 3.0 fixed.png Superell 3.0 3.0 fixed.png Superell 3.0 0.2 fixed.png

  • A cline primitive raytraced in different views. You can see that it's a primitive whose raytrace is view-dependent. We use a pipe to represent it when it's converted to b-rep, whose raytrace is view-independent. The shape of the pipe is according to what we see when plotting a cline with the draw command in MGED. (Two different views, left: implicit, right: brep)

Cline implicit 1.png Cline brep 1.png Cline implicit 2.png Cline brep 2.png

Original development timeline

  • - May 21 (~4 weeks)
    • Study materials on NURBS/BREP etc
    • Read the codes in librt/primitives
    • Get familiar to OpenNURBS
    • Fix some bugs and make patches
    • Implement a method for convenient testing (finished)
  • May 21 - June 10 (~3 weeks)
    • Modify implemented conversions if not finished
      • pipe
      • sph, ell, tor, hyp
      • eto, extrude, revolve, etc.
  • June 11 - June 18 (~1 week)
    • Final examination week in our school
  • June 19 - July 1 (~2 weeks)
    • Still work on existing conversions
    • Work on non-origin primitives
      • Deduce transformation matrices
      • Apply the transformation
      • Test the results and write documents
  • July 1 - July 29 (~4 weeks)
    • Add new conversions to missing primitives
      • Test whether it works well
      • Write clear documents
      • From easy ones to hard ones
    • July 1 - July 8 (1 week)
      • rec
      • ars
      • half
      • ell1
    • July 8 - July 15 (1 week)
      • metaball
      • pnts
      • part
      • grip
    • July 15 - July 22 (1 week)
      • superell
      • cline
    • July 22 - July 29 (1 week)
      • hf
      • other missing primitives
  • July 29 - August 13 (~2 week)
    • Write a convert for whole
      • Write a function to walk the tree
      • Add a command to MGED
      • Discussions and documents
    • Test the work and fix bugs
  • August 13 - August 20 (~1 week)
    • Pencil down data
      • Improve documentation
      • Evaluations
  • Post-GSoc
    • Further involvement with BRL-CAD :)
Retrieved from "https://brlcad.org/w/index.php?title=User:Phoenix/GSoc2012/Reports&oldid=4050"