小笔记 - houdini

1，compress volume and VDB

https://www.vfxarabia.co/compress-houdini-vdb-volume-cache

2, read attr by uv in COPNET

vector uv = set(X, Y, 0);
vector clr = uvsample(next, "Cd", "uv", uv);
R = clr.x; G = clr.y; B = clr.z;