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About Gavin

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  • Name Gavin
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  1. Your Emission Type on your Pop Source is set to "Scatter on Surfaces". Which means it's not using the actual points of your sphere, it's scattering randomly placed points onto the surface of your sphere and doing an average on the attributes from the spheres nearby points. Thus your attributes are no longer unique. Change your emission type to either "Points" or "All Points" and you'll be all set.
  2. Joe's solution should work assuming your fire source isn't animated and you're not interacting with anything animated throughout the sim. Your easiest option is to set your dop start frame to a negative number, like -24, to get your preroll. Another route would be to save out .sim files until you get a fire look that you like, and then you can use that sim file as your "Initial State" for your dop network.
  3. It could be. It seems to be creating degenerate geo in some cases, which causes the polyfill to error out. If it helps, I got much better results out of the boolean node. I don't know how the speed stacks up against the intersection analysis sop, but it's certainly faster that going through a for each. SlicerH16.002.hipnc
  4. My preferred way of doing something like this is the polyframe node. Just swap the "Tangent Name" to up and you're good to go. Also unless you're carrying through a specific attribute then you probably want to turn off "Copy Point Attributes" in your copy sop.
  5. Based on the image on the right it looks like your normals are inverted on part of your geo. Likely from doing a negative extrusion or scale. Is this originally a Houdini geo though, these images look like Maya and Zbrush? Do you have a hip file we could look at?
  6. If you haven't already then its a good idea to check out the expression cookbook for a starting point. If you just open the houdini help browser and look for "expression cookbook" it should pop up. You can also read through the "expression functions" list if you just want an idea of whats possible. Good luck!
  7. Hey Nathan, You can get this fairly easily with an expression like ceil($F/8) ceil will round up the fraction to the next integer, and since we divide by 8 here it will change every 8 frames. You could put this this expression in your timeshift or you could remove your timeshift altogether and just put the expression in your seed. Hope this helps.
  8. One way would be to group the patches coming out of your polyfill, and then delete everything outside of the patches group.
  9. I almost always stay away from concave objects. They just have too many issues for my liking. I'm also not sure why you want too solve this kind of motion with collision objects as opposed to constraints, but that is up to your discretion. With that said you can get better results in this case by moving to RBD and using volume collision. Also the clasps on the briefcase are very thin, so I broke them into their own collision objects. Scene attached. Briefcase2.hipnc
  10. Assuming you have clean geometry then you shouldn't have to promote your UVs to points when transferring to Maya. Is Maya throwing any errors or warnings in the script editor when you do your import? If I know I'm going to be taking geo with UVs over to Maya I will often triangulate the mesh early on in Houdini as I find this lessens the change of issue when switching packages later. Also if you have a hip or an alembic file I could look at then that would make it easier to help.
  11. Maya is notoriously bad at handling high object count scenes, so if you're going to be sending it thousands of separate objects you have to make sure maya is happy with what you're handing it. The file format and size are actually less important than making sure that maya doesn't have to try and load each piece in and treat it as a separate object. As Ben has mentioned this can be achieved by making sure to pack the geo in the proper way so that it comes into Maya under a single shape node. I say the proper way because the different alembic packing and export options will affect how maya interprets and breaks apart what you give it.
  12. If you want to make your objects overlap less you can try playing with your collision padding and shrink amount. By default these fields are linked, so increasing your padding won't have much effect on the exterior padding of the object. However if you turn off the shrink amount, or break the connection between the two and dial them in separately you might find a good ratio for your sim.
  13. Rather than trying to move points to do redo the same voronoi fracture on every frame, its better to do the fracture and then put the motion back. You can use an xyzdistance node to create your own sourceprim and sourceprimuv. See if this hip does what you want. beamFracture_abc.hipnc
  14. Hey Chris, The cooking interrupted or cant compute are often issues to do with stopping Houdini while its mid calculation. You can either restart Houdini or find the node where cooking was interrupted and flick the bypass on and off. As far as your pyro goes, your resize container is looking for density to determine its size , however there isnt enough density at the start of your sim so it just jumps the box back to the origin and you get empty frames. if you add "fuel" to your "reference field" then it will give the density enough time to build and the resize will follow it. I am curious as to why you're using combustion here to create your smoke as opposed to sourcing directly from a density volume?
  15. Can you give a little more information of what you're trying to accomplish? You could control the rotation of each piece separately by giving each piece an attribute and then sending that through a ramp to remap the values. I've done a quick example using a attribute vop although I'm not sure if this is what you're looking for. copy_222_trans_rotate.hipnc