Blender Git Commit Log
Git Commits -> Revision 1e65bf5
Revision 1e65bf5 by Lukas Toenne (gooseberry, gooseberry_farm, hair_immediate_fixes, hair_system, temp_constraint_volume, temp_hair_flow, temp_hair_modifiers, temp_motionpaths) September 16, 2014, 12:36 (GMT) |
Fix for Sintel hair bug. The hair solver needs sane input to converge within reasonable time steps. In particular the spring lengths must not be too difference (factor 0.01..100 or so max, this is comparable to rigid body simulation of vastly different masses, which is also unstable). The basic hair system generate strands with equally spaced points, which is good solver material. However, the hair edit operators, specifically the cutting tool, can move points along the strands, creating tightly packed hair points. This puts the solver under enormous stress and causes the "explosions" observed already during the Sintel project. The simple solution for now is to exclude very short hairs from the simulation. Later the cutting tool should be modified such that it keeps the segments roughly at the same length and throws away vertices when the hair gets too short (same goes for the extension tool). The hair system should have a general mechanism for making sure that situations such as this don't occur. This will have to be a design consideration for replacements in any future hair system. |
Commit Details:
Full Hash: 1e65bf5824a4b3ea0faf04918109d693d3bdad95
Parent Commit: fd38892
Lines Changed: +57, -18
1 Modified Path:
/source/blender/blenkernel/intern/particle_system.c (+57, -18) (Diff)