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Adam Ferestad

DOPs behaving badly: Grains source pyro for dust

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Hey all, I'm trying to play with a scene where I'm doing some explosions on a beach and I wanted to make sure I had all of the individual effects down before I started trying to do the large scene.  I already figured out how I want to do the explosions with a sparse pyro, and I got the grains solver to behave how I want for the sand to be kicked up, but when I tried to add a pyro solver to the sand grains I got some weird results, so I went to make a simple example scene that would be faster to simulate and it started doing even worse stuff.

My grains scene is giving me some really bad smoke that doesn't seem to be advecting and is only generating on each frame of my cached grains.  Seeing this, I found an example file which was using a pops simulation to generate smoke, so I tried to apply what was in there to a simple test scene, and for some reason my sims are applying giant black box sprites to the particles before it even gets into the pyro simulation.  

If you have some advice on how to handle the dust from sand explosion that would be great.  If you have any idea why I'm getting the sprites, that would be amazing as well.  The files aren't the cleanest, but here they are.  I am using GridMarkets caching and rendering for the sand file, so if you don't have their nodes you can just delete them and replace them with filecache nodes.

SandboxPop.hip

pyroFromParticles.hip

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The smoke dissipation in sandboxpop.hip is too high. Did you mean to set it at 0.05 and not 0.5? Also you don't have a temperature attribute on the points going into Volume Rasterize Attributes, which means that it won't create a temperature volume that your sim can source. Without temperature your smoke won't rise and because dissipation is so high it pretty much vanishes by the time the next frame rolls along.

As for the black box sprites, you just need to delete the shop_materialpath prim attribute going into the popnet to prevent the popnet from copying the attribute over to each point that it scatters on the source geometry.

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3 hours ago, ziconic said:

The smoke dissipation in sandboxpop.hip is too high. Did you mean to set it at 0.05 and not 0.5? Also you don't have a temperature attribute on the points going into Volume Rasterize Attributes, which means that it won't create a temperature volume that your sim can source. Without temperature your smoke won't rise and because dissipation is so high it pretty much vanishes by the time the next frame rolls along.

As for the black box sprites, you just need to delete the shop_materialpath prim attribute going into the popnet to prevent the popnet from copying the attribute over to each point that it scatters on the source geometry.

Thank you so much for those, I will implement the changes and keep moving forward.  

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OK, so now I have a new problem.  When I merge my volume with my sand points, nothing renders.  Somehow I ended up with duplicate volumes in my simulation, which I have no idea how to reconcile, and the volume itself won't render when I solo it.  It is the weirdest thing I have ever seen.

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It's hard to tell what's happening without seeing the hip file.

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