I also wanted to try and tackle this in houdini. I’m pretty new to houdini in general so I’m still not sure how to go about writing out the vert values to pixels in a texture. However I did start to pick apart what the 3d max tool does and wrote down the following notes. Maybe they will be helpful to you guys, who knows
What the Epic tool seems to do:
Writes out a 32 bit floating point EXR
pixels in the X axis correspond to vert numbers
pixels in the Y axis correspond to frames in the timeline
start in top left corner of the image.
first X row seems to be the “default” pose, so all pixel values are 0, and each pixel value in the rows that follow is relative to the first row.
to inspect an image:
open it in the comp window in houdini, set the file node to 32 bit floating point depth and turn off linearize image. right click in the comp view and turn on “inspect”. Run the mouse down each column in the image to see the rgb values, which show you the position offsets per vert/per pixel
3d max vert numbering seems to start at 1, not 0.
so in X:
pixel 0 = vert 1
pixel 1 = vert 2
pixel 3 = vert 3
exr pixel coords seem to start bottom left
the tool starts writing from top left.
so frame 0 doesnt equal pixel column 0, its reversed.