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Showing results for tags 'volume vop'.
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Hello to everyone! I'm fairly new to Houdini and to vfx at all and been struggling trying to do this by trial and error and searching in forums. Even though I have learned a lot by doing that, I think it's better to ask for someones help. I want to create some dust clouds (like a small dust storm) for a shot. Because the area that I'm trying to fill is big and my resources are limited, I thought it would be a good choice trying to achieve the effect using SOPs instead of a smoke simulation in DOPs. The setup related to this part of the effect is basically some boxes each modified by a Volume VOP to add some noise and animation by frame. I read that Billowy Smoke Shader can help you to get a more fluffy look at rendering. My first frame was great, but the next weren't as good because of the noise. The shader is supposed to use the rest field of your simulation to position it, but I'm in SOPs. Another user asked for something like this in the forum: He says: "just create a vector rest volume in the beginning that has the world coordinate of each voxel as its value. Be careful to do all the same advection operations on your rest volume as you do on your density volume". But I think a main difference is that they are working with shaped geometry and my whole dust storm is, well... a box. Until now my tests have been: 1.- Expose rest attribute with a wrangler before my volume vop and create a surface attribute named rest. 2.- Create it after the volume vop. 3.- Create the noisy volume, then convert it back to polygons, add a rest field and then again convert it to fog. And nothing worked. My questions are: 1.- Is there are way to use a rest field from SOP to shape noise in the billowy shader? If yes, what is it and how do you work it. 2-. Or would it be better to create a noisy volume, convert back to geometry, add pyoclastic noise and convert it back to volume? Thank you in advance. I would really appreciate your comments.
Hello, I am playing around with the VDB stuff lately and most of it works great. But I noticed that i can't use a plain VDB node and create based on the dimension source a volume, like a velocity field. It always said "<empty>". I like to create a vector field and then manipulate it by the Volume Vop as with the standard Houdini Volumes. Any tips or a workflow explanation would be great. Thanks nap vdb_empty.hipnc.hip