Volumes 101 - "Dissolving" Geometry
Added 2018-02-12 08:47:43 +0000 UTCAs promised here's the technique we used to create the volume for last week's tutorial. It's a setup we find ourselves using quite frequently in commercial projects, especially when it comes to still renderings. Creating a velocity volume to drive your advection makes the behaviour and look of your volume extremely adaptable and art directable. Which comes in very handy when you're trying to meet a client's feedback :)
Comments
Hi Raghid, make sure you enter density in the volume visualisation node's density attribute field. That changed a few versions ago. Now you can/have to specify which field to visualize. Hope that solves it. Cheers, Mo
Entagma
2020-09-14 20:55:39 +0000 UTCRay J
2020-09-14 20:42:30 +0000 UTCHi Luis, why not use the volume's gradient? This gives you vectors pointing in the direction of the steepest descent of your volume values. Can be calculated either by using the VDB Analysis SOP or the Volume Analysis SOP - depending on the type of your volume. Cheers, Mo
Entagma
2020-06-04 17:16:32 +0000 UTCHello Mo. You should be quite busy by now, but I try to ask anyway: how would you generate velocity out of a more complex and defined density volume? Using noise is already clear and effective in many cases, but let's say I want to advect particles through a Volume generated by a CT Scan. An object with stuff inside, but no infos about tangents or something similar. How to generate some Velocity info out of those density values? I'd guess using VEX to search for the voxel with the closest grey value to the actual one? Don't know, may be a good follow up tutorial?... :)
Luis B
2020-06-04 12:43:24 +0000 UTCim going to keyframe the ramp to animate it that way.. but there is probably better ways to animate it
Mark Pamatat
2019-08-05 20:51:05 +0000 UTCThank so much man. this are great!
Jose Medina
2018-08-02 18:49:17 +0000 UTCThank you for the cool technique. Is there a quick way to animate this or to turn it into a simulation?
Acroyear
2018-05-20 22:06:22 +0000 UTC
