Category: hou-effects

Archived post by mattiasmalmer

i was just mucking about with a slightly neater way of approximating an object with spheres. the vdbtoSpheres is a little rough. here my version use 1700 spheres and vdbtoSpheres use 3300. and as you can see it does considerably worse even with twice the numbers.

Attachments in this post:
http://fx-td.com/houdiniandchill/wp-content/uploads/discord/20241410/29/24/houdini_zCpch2dAjK.mp4
http://fx-td.com/houdiniandchill/wp-content/uploads/discord/20241410/29/24/shapeasspheres.hiplc

Archived post by fabriciochamon

@flight404 @what_i_found a couple music experiments

visualizers, midi players, etc

there is one I find particularly interesting (“midi_rbd_balls” folder), it reads a midi file, simulates rbd balls being dropped at keys (in sync with the file), then reads ball impact data from dopnet and finally generates a sound for each note based on that impact (saves final .wav to disk). So in a way is a poor’s man very basic midi synth in houdini.

inspiration for this is “Animusic”.. anyone remember that ?? ollllddd https://www.youtube.com/watch?v=hyCIpKAIFyo

Attachments in this post:
http://fx-td.com/houdiniandchill/wp-content/uploads/discord/20243305/30/24/houdini_music_sample_scenes.zip
http://fx-td.com/houdiniandchill/wp-content/uploads/discord/20243305/30/24/hou_music_examples.png

Archived post by fabriciochamon

@flight404 @what_i_found a couple music experiments

visualizers, midi players, etc

there is one I find particularly interesting (“midi_rbd_balls” folder), it reads a midi file, simulates rbd balls being dropped at keys (in sync with the file), then reads ball impact data from dopnet and finally generates a sound for each note based on that impact (saves final .wav to disk). So in a way is a poor’s man very basic midi synth in houdini.

inspiration for this is “Animusic”.. anyone remember that ?? ollllddd https://www.youtube.com/watch?v=hyCIpKAIFyo

Attachments in this post:
http://fx-td.com/houdiniandchill/wp-content/uploads/discord/20243305/30/24/houdini_music_sample_scenes.zip
http://fx-td.com/houdiniandchill/wp-content/uploads/discord/20243305/30/24/hou_music_examples.png

Archived post by lewis.taylor.

how bad is your CPU? your file sims in about 5 seconds a frame on my macbook

but, the slowness is down to how you’re essentially replicating the whole wind tunnel in POPs and then feeding that into pyro. Much faster to do what Matt did, just emit density into it and let wind do it’s job.
Couple things in general; * use the top level wind, it’s a simplified one compared to gaswind, so it’s faster (also you plugged gas wind into advection instead of force) * up the clamp level for dissipation from the awful default of 0.005 to something like 0.04, unless you render with density at 0.01 you’d never see those voxels, it’s a terrible default * use the voxel res calc tool I made for that SYD HUG presentation, then you know exactly what res to sim at for the given camera, distance, and render res * if you need uber fine density fidelity look to use the velocity scale multiplier to sim vel at a lower res than density, it will save you a lot of sim time.

Archived post by lewis.taylor.

how bad is your CPU? your file sims in about 5 seconds a frame on my macbook

but, the slowness is down to how you’re essentially replicating the whole wind tunnel in POPs and then feeding that into pyro. Much faster to do what Matt did, just emit density into it and let wind do it’s job.
Couple things in general; * use the top level wind, it’s a simplified one compared to gaswind, so it’s faster (also you plugged gas wind into advection instead of force) * up the clamp level for dissipation from the awful default of 0.005 to something like 0.04, unless you render with density at 0.01 you’d never see those voxels, it’s a terrible default * use the voxel res calc tool I made for that SYD HUG presentation, then you know exactly what res to sim at for the given camera, distance, and render res * if you need uber fine density fidelity look to use the velocity scale multiplier to sim vel at a lower res than density, it will save you a lot of sim time.

Archived post by mestela

played with it some more, getting some nice wake/vorticies happening

could be better, getting a handle on the various controls

using a proper collision sdf and collision v lets you control the eddies better; at the default its a bit too extreme and kicks the wake too wide, this is scaling v down to 0.3

Attachments in this post:
http://fx-td.com/houdiniandchill/wp-content/uploads/discord/20240904/22/24/Kapture_2024-04-22_at_08.36.43.mp4
http://fx-td.com/houdiniandchill/wp-content/uploads/discord/20240904/22/24/pyro_for_paul_v02.hip

Archived post by mestela

played with it some more, getting some nice wake/vorticies happening

could be better, getting a handle on the various controls

using a proper collision sdf and collision v lets you control the eddies better; at the default its a bit too extreme and kicks the wake too wide, this is scaling v down to 0.3

Archived post by squidbean

So there is a “trick” / non-obvious way to generate collision shapes for ragdolls now that does not require you to sit and click for hours manually

this thing is for kinefx (not crowds) but….

make sure you have a rest transform on the skeleton going in and unpacked geo in the 3rd input

you can add the shapes into the crowd setup as a new agent layer, like any other skin

call it collision, but don’t display it

and in your collision layer you reference “itself” basically the existing collision layer shapes

and because its generated from the skeleton, all the names etc match

that way, this is what the kinefx tool generates

and the agent collision layer adopts it nicely

saves you a few hours of raging at the terrible UI while you try to align pill shaped…. %$@!

Attachments in this post:
http://fx-td.com/houdiniandchill/wp-content/uploads/discord/20245904/12/24/CrowdVellum-v06.mp4
http://fx-td.com/houdiniandchill/wp-content/uploads/discord/20245904/12/24/image.png