solver transfer attribute, eg. colour accumulation

i always have to look this up on cgwiki...

the left stream is some sweat drops falling down a surface.. the right stream is the surface. 

It goes into a solver

The slight 0.0075 blend in the blendshape causes a slight fade of the attribute being transferred. Leaving it at zero will result in an absolute solver-accumulation of the value.

exporting custom attributes in Alembic to Blender

We use the setattribtypeinfo function to force an attribute to be a color type. Just like Cd usually is.

This will probably streamlined and not necessary in future versions of Blender, but it seems like it is still necessary atm (Jan 2023)

using a point wrangle, set to detail (so it only runs once)

 setattribtypeinfo(0,"point","attributename","color");

here I'm forcing an attribute called attributename to be recognised as a color type & not just 3 floats.
I'm using the rop_alembic output to write the abc file.

separating objects for booleans/other things

Case example - you have a 


To separate out an object, maybe for booleaning, or to avoid intersections when doing some other sort of calculation, make a point class attribute (connectivity)
then in a point wrangle do something like this-

@P.x+=@class;
@P.y+=@class;

This should separate the pieces enough. If not, use a multiplier.
Then promote the class to a primitive attribute - for some reason Boolean Fracture doesn't carry across the class attr to any newly generated points when it is left as a point attr.


Do your booleans...you might want to scatter some points on the surfaces or copy some turbulent grids onto the object points.

Bring the class attribute back to point level and then do the reverse transformation

@P.x-=@class;
@P.y-=@class

 link any multipliers you might have to save time changing values in multiple boxes!