Weekly Recap 3
Its Friday. Time for my third What I Found weekly recap. Picked up a little Houdini and Touchdesigner knowledge on the day job and some personal work, check it out below.
I made some changes to my Touchdesigner instancing set up. It now includes color. I use a reorder TOP to shuffle the greyscale values I’m using for index into the alpha channel, and then use the R G B channels to drive color. I color the incoming greyscale with a lookup TOP.
Touchdesigner Not all noises are created equal. Watch the gpu / cup usage on the Noise CHOP. It varies a lot as you change noise types Hermite is a good cheap one. Seemingly small differences really add up in large projects.
Another optimization discovery… With noise you can animate the position of a model via the xform properties of a GEO container with little to no cost. Attempting to do it inside a GEO with a Transform SOP will bring your project to a crawl. ~5 fps difference.
Back in Houdini, my main software I fought with cryptomattes during the day and had fun with space switching at nights on a personal project.
Space switching is when you need an object to be parented to one thing for a time, then a different thing for some other time. It can be more complicated than it sounds, but I found it wasn’t too bad in Houdini.
Setting up the instances isn’t hard in TD, but coming from C4D or Houdini it feels a bit obtuse. To instance directly onto points, specify a sop in the instance tab of a geo container. The geometry you have inside the geo will be instanced.
Before going further I’ll assign my texture. I feed my movie file into a Texture3D TOP. This pulls x number of frames into a stack of frames. Feed the tex3d into a mat, then when assigned to your geo, you control how the images are assigned in the instance 2 tab (later step)
I used the shelf tool for parent blend, was surprised to see this is a CHOP operation. Dove inside and played with the parameters in the CHOP net. The update offset toggle is king here.
Cryptomatte is great, but can be trouble to set up since it needs unique materials or object ID’s (unique Obj containers at object level). My case I was rendering particles, didn’t want to instance geo, just render raw points. I’d also built out 25 variants at the SOP level.
Duplicate mats in SOPs doesn’t work. Rendering with RS as points wont pick up the mat on particles, the attrib to assigns mats is a prim attrib. Have to assign the mat on the Obj instead. I had to make 25 Objs and merge in my set ups one by one. No biggie, next time I’ll know.
Thanks for reading the long thread. Hope it’s helpful or interesting. Next week there wont be one, because I won’t be learning any Houdini or Touchdesigner on vacation. I’ll be back in August with more.
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