bmesh: weight colors layer not alway tracked properly #29451

New Issue

Andrew Wiggin · 2011-11-29T18:34:38+01:00

Andrew Wiggin commented

2011-11-29 18:34:38 +01:00

%%%MiikaH reported to me that it seems like BMesh is not generating CD_WEIGHT_MCOL layers on the tesselated faces based on the CD_WEIGHT_MLOOPCOL layers. I do recall seeing places in the code that should probably be handling this and weren't.

Additionally, I've discovered if CD_ID_MCOL and CD_TEXTURE_MCOL, which don't have corresponding loop color layers. From a quick look at the code, it looks like CD_ID_MCOL isn't used anymore, and CD_TEXTURE_MCOL looks like it is created and used during render only, so it might be fine as is, but it would be good for someone to spend a bit more time to confirm this, when addressing the above weight colors issue.%%%

%%%MiikaH reported to me that it seems like BMesh is not generating CD_WEIGHT_MCOL layers on the tesselated faces based on the CD_WEIGHT_MLOOPCOL layers. I do recall seeing places in the code that should probably be handling this and weren't. Additionally, I've discovered if CD_ID_MCOL and CD_TEXTURE_MCOL, which don't have corresponding loop color layers. From a quick look at the code, it looks like CD_ID_MCOL isn't used anymore, and CD_TEXTURE_MCOL looks like it is created and used during render only, so it might be fine as is, but it would be good for someone to spend a bit more time to confirm this, when addressing the above weight colors issue.%%%

Andrew Wiggin commented

2011-11-29 18:34:38 +01:00

Changed status to: 'Open'

Campbell Barton commented

2011-12-02 18:45:07 +01:00

%%%Could you give steps to redo a bug with weight colors?, on simple tests at least I couldn't get it to break.%%%

Miika Hamalainen commented

2011-12-03 19:45:19 +01:00

%%%This issue mostly affects Dynamic Paint 3D view preview code, and it's not "repeatable" with test files.

In trunk, I used CD_WEIGHT_MCOL data layer to save the preview from the modifier and it is automatically preserved for opengl drawing code through modifier stack.

In case of bmesh, it is outputted to "CD_WEIGHT_MLOOPCOL" loop data layer to even possibly be transferred to other modifiers etc. (See i.e. dynamicpaint.c line 1563->) However, currently that WEIGHT_MCOL layer doesn't get generated from the WEIGHT_MLOOPCOL data, and is therefore not available for the opengl draw code.

Currently "Weight Paint mode" has a special setup to regenerate both MCOL and MLOOPCOL for every modfier through DerivedMesh.c -> add_weight_mcol_dm().

I think it should work like this:

Weight Paint mode only outputs the CD_WEIGHT_MLOOPCOL from add_weight_mcol_dm().
Dynamic Paint also outputs the "CD_WEIGHT_MLOOPCOL".
Customdata code should automatically generate "CD_WEIGHT_MCOL" from that loop data like it does for the basic "CD_MLOOPCOL" layer etc.

I think it might also be good idea to rename those weight layers to something general for 3d view drawing only, because that's what they are is used for. Having a WEIGHT in the name is quite confusing already since it only stores colors. For example CD_OPENGL_MLOOPCOL or CD_PREVIEW_MLOOPCOL would describe it better and would better fit also for tools like Dynamic Paint etc. :)%%%

%%%This issue mostly affects Dynamic Paint 3D view preview code, and it's not "repeatable" with test files. In trunk, I used CD_WEIGHT_MCOL data layer to save the preview from the modifier and it is automatically preserved for opengl drawing code through modifier stack. In case of bmesh, it is outputted to "CD_WEIGHT_MLOOPCOL" loop data layer to even possibly be transferred to other modifiers etc. (See i.e. dynamicpaint.c line 1563->) However, currently that WEIGHT_MCOL layer doesn't get generated from the WEIGHT_MLOOPCOL data, and is therefore not available for the opengl draw code. Currently "Weight Paint mode" has a special setup to regenerate both MCOL and MLOOPCOL for every modfier through DerivedMesh.c -> add_weight_mcol_dm(). I think it *should* work like this: * Weight Paint mode *only* outputs the CD_WEIGHT_MLOOPCOL from add_weight_mcol_dm(). * Dynamic Paint also outputs the "CD_WEIGHT_MLOOPCOL". * Customdata code should automatically generate "CD_WEIGHT_MCOL" from that loop data like it does for the basic "CD_MLOOPCOL" layer etc. I think it might also be good idea to rename those weight layers to something general for 3d view drawing only, because that's what they are is used for. Having a WEIGHT in the name is quite confusing already since it only stores colors. For example CD_OPENGL_MLOOPCOL or CD_PREVIEW_MLOOPCOL would describe it better and would better fit also for tools like Dynamic Paint etc. :)%%%

Bastien Montagne commented

2012-02-27 08:29:50 +01:00

%%%Think this one is also related to [#30234]…%%%