Hair Particle system does not respond properly to hair Dynaimcs #30557

New Issue

Karl Nyman · 2012-03-15T22:56:51+01:00

Karl Nyman commented

2012-03-15 22:56:51 +01:00

%%%The "wig" mesh in the linked-to .blend was created in a 2.5x version (earlier than 2.59 iirc), but did not have Hair Dynamics set for it until it was used in 2.61.0 r42615 (BF release). Using the same settings as the two test meshes in the same file (both created in 2.61), which do respond as expected, the keypoints of the problem hair system parent strands seem frozen in place when the emitter mesh moves. This can be changed by assigning weight 1.0 to all keypoints of the strands, but this also makes Hair Dynamics useless.

test file (19Mb) is at http://www.pasteall.org/blend/12495

I'm not sure this is a classic "bug" but the problem is serious enough to warrant investigation in case some aspect of Hair Particles is at the root of the problem (pun intended).

Microsoft® Windows Vista™ Home Premium
Version 6.0.6002 Service Pack 2 Build 6002
MD Athlon(tm) 64 X2 Dual Core Processor 5600+, 2800 Mhz
3.00 GB RAM
ATI Radeon X700 256Mb VRAM%%%

%%%The "wig" mesh in the linked-to .blend was created in a 2.5x version (earlier than 2.59 iirc), but did not have Hair Dynamics set for it until it was used in 2.61.0 r42615 (BF release). Using the same settings as the two test meshes in the same file (both created in 2.61), which do respond as expected, the keypoints of the problem hair system parent strands seem frozen in place when the emitter mesh moves. This can be changed by assigning weight 1.0 to all keypoints of the strands, but this also makes Hair Dynamics useless. test file (19Mb) is at http://www.pasteall.org/blend/12495 I'm not sure this is a classic "bug" but the problem is serious enough to warrant investigation in case some aspect of Hair Particles is at the root of the problem (pun intended). Microsoft® Windows Vista™ Home Premium Version 6.0.6002 Service Pack 2 Build 6002 MD Athlon(tm) 64 X2 Dual Core Processor 5600+, 2800 Mhz 3.00 GB RAM ATI Radeon X700 256Mb VRAM%%%

Karl Nyman commented

2012-03-15 22:56:51 +01:00

Changed status to: 'Open'

Sergey Sharybin commented

2012-03-19 15:06:14 +01:00

%%%Janne, maybe you can look into this issue?%%%

Karl Nyman commented

2012-03-23 16:23:56 +01:00

%%%Any progress here? I'll be starting final rendering soon, and need to know if I have to reconstruct the wig in order to use Hair Dynamics. That's something I'd like to avoid if possible.%%%

Karl Nyman commented

2012-03-30 18:13:12 +02:00

%%%In the process of trying to reconstruct this wig, I may have discovered the cause of the problem. During the editing of the particle hair I used a number of tools, and tested the Hair Dynamics at a number of points in the editing process. At one point, it suddenly failed in the same manner as the original problem system.

Going through each tool step by step I found that the Add tool seems to be causing the glitch. After using Comb, Cut and the Length tools, and testing Hair Dynamics after using each, I began filling out some bald spots using the Add tool. The next test of Hair Dynamics failed.

I was able to repeat this using an entirely new hair particle system applied to the original emitter mesh. Adding a single strand did not cause the failure, but after adding a number of new strands across the surface of the mesh, the failure then occurred. I used the Interpolate option in all these tests.

I'll test with a different emitter mesh and try and narrow down the specific point at which the failure happens.%%%

%%%In the process of trying to reconstruct this wig, I may have discovered the cause of the problem. During the editing of the particle hair I used a number of tools, and tested the Hair Dynamics at a number of points in the editing process. At one point, it suddenly failed in the same manner as the original problem system. Going through each tool step by step I found that the Add tool seems to be causing the glitch. After using Comb, Cut and the Length tools, and testing Hair Dynamics after using each, I began filling out some bald spots using the Add tool. The next test of Hair Dynamics failed. I was able to repeat this using an entirely new hair particle system applied to the original emitter mesh. Adding a single strand did not cause the failure, but after adding a number of new strands across the surface of the mesh, the failure then occurred. I used the Interpolate option in all these tests. I'll test with a different emitter mesh and try and narrow down the specific point at which the failure happens.%%%

Ton Roosendaal commented

2012-10-23 11:30:26 +02:00

%%%It's quite clear to everyone that the particle system went into orphaned state - it is at its end of lifecycle.
There are many reports on various cases that fail to work, but all attempts to get it work predictably have failed. Also for Sintel we cursed hair dynamics every day!

It's a real shame to have this issue open for so long, but I can only move this to our todo tracker as unsolved issue now.
Best thing I can promise is our new node particle system, being developed for over a year already and hopefully ready in 3-6 months.

Link to your report for future reference:
http://wiki.blender.org/index.php/Dev:2.5/Source/Development/Todo/Tools#Particles%%%

%%%It's quite clear to everyone that the particle system went into orphaned state - it is at its end of lifecycle. There are many reports on various cases that fail to work, but all attempts to get it work predictably have failed. Also for Sintel we cursed hair dynamics every day! It's a real shame to have this issue open for so long, but I can only move this to our todo tracker as unsolved issue now. Best thing I can promise is our new node particle system, being developed for over a year already and hopefully ready in 3-6 months. Link to your report for future reference: http://wiki.blender.org/index.php/Dev:2.5/Source/Development/Todo/Tools#Particles%%%

Ton Roosendaal commented

2012-10-23 11:30:26 +02:00

Changed status from 'Open' to: 'Archived'

Ton Roosendaal closed this issue

2012-10-23 11:30:26 +02:00

Sign in to join this conversation.

No Label

Download

What's New

Blender Studio

Manual

Developers Blog

Documentation

Benchmark

Blender Conference

Development Fund

One-time Donations

Hair Particle system does not respond properly to hair Dynaimcs #30557