Tatsu

Digging into the particle fluid surface node, I found that when the surface VDB was being converted to polygons, there were four small strips of geo at the bottom of the resulting mesh. The conversion process was not just leaving the top surface geo. Something to do with the surface mask going into convertvdb being slightly the wrong size perhaps? If anyone does run into this, dropping the Regional Voxel Scale on the particlefluidsurface node from default 4 to 3 seems to have fixed it. Caching the surface now so I'll check for bad frames when it's done. Seems like it's maybe just some bad combination of particle separation, voxel size, and regional voxel scale causing the masking VDB to leave a little extra on the bottom edge when converting to polys.

I'm using the Ocean Flat Tank Shelf tool to do a flip sim, and then render an extended ocean with the ocean displacement tools. Basically, trying to follow along with the example shown in the Houdini 16 Ocean tools masterclass. The issue I'm having is, when I use the Flattening tools on the particlefluidsurface sop, I get a lot of extra geometry below the surface. The default Extrude Polygons mode is planar and I get a lot of planes below the surface. If I change to Along Each Axis, I get the extra geo planes above the surface as well. Has anyone run into this issue? I didn't really change any simulation settings on the flattank_sim from what the shelf tool set up. I suppose it's possible the new narrow band settings are somehow breaking the flatten geometry tools? I should test with the narrow band turned off maybe but I would hope that wouldn't break the setup. I'm hoping someone else has seen this before and found a solution.

Thanks guys. I should have checked for a new build!

I'm doing some Bullet tests, trying to replicate a workflow I use in 3DS Max; something that works in both pFlow and Thinking Particles. I am having trouble getting active RBD objects to react properly to an animated object. I can't seem to get Bullet to evaluate the force of impact from a static object the same way it does from an active object with velocity. To test this, I created an active RBD sphere object and gave it an initial velocity to launch it at a wall of blocks. I then animated a copy of the sphere to match the active sphere and ran the simulation again with the static RBD sphere and it doesn't affect the wall of blocks the same way. I've tried animating a transform inside the geometry and adding a trail SOP to the animated sphere to compute velocity. Regardless of what I try, wall of blocks don't seem to get much impulse from the static object. Any thoughts? bulletCompare_001.hipnc

There is no impulse birth rate in the split pop. The number of birthed particles is set by the birth probability which I have set to 20 and 30.

So, I have a fairly simple situation. I have a Geo sop within which is a popnet. In the popnet, I have four operators. A location pop feeding into a force pop feeding into a drag pop feeding into a split pop. Everything works as expected up until the split pop. On the source tab of the split pop, the emission type is set to particle. The birth tab has a probability of 20 to 30. Nothing really set in the attributes tab. In the activation parameter, I have the following expression: $FF % 20 == 0 What I expect to happen is that the split pop will birth particles on every frame that is a multiple of 20. What actually happens is that the split pop births particles at frames 40, 100, 160 and 220. When I view the result of the expression in the activation parameter, I see the results I expect. It evaluates to 0 on every frame except 20, 40, 60 ect... Why is my split pop not birthing new particles every time my expression evaluates to "1"????I assume this has to be a setting somewhere. Everything behaves as I expect except for the actual lack of particles being born. Any thoughts?

Congrats you two. Deffinitely going to study these and hopefully learn something about CHOPS....

Thanks everyone. Hopefully I'll revisit this later when I know more about the program. I'm pretty sure the was its constructed now would seriously hamper any attempts to animate it coming together....

And I guess will call this one final. I'm sure everything in the scene is a bit clunky in it's execution. cards_V04.hipnc

Thanks for the comments. I had tried the copy SOP but had a hard time manipulating the normals and up vectors to get the layout I wanted so for now its almost all sweeps. I do realize that this makes it much more difficult to randomize things and probably animate as well. However, I know very little about surfacing and rendering in Houdini as of yet so I can tackle that stuff later. As it is, it took me quite some time just to get a properly shaded surface. I must say, even with such a simple scene and very simple lighting, I love the look of the mantra renderer. cards_V03.hipnc

Progress so far tonight.... Might try and figure out how to get some texture on it and get rid of the shading errors tomorrow.

Hey everyone. I know this challenge is almost over but I literally just started learning Houdini this past weekend and this looked like a good opportunity to see what I've learned so far. Then I hit a stumbling block right off the bat. So... what I've done is ran a 2 segment line through a sweep on a resampled curve, skinned it and made a selection of the points running down the middle for the template of the copy sop. I've added a slight Y rotation in the copy SOP to get the overlap I want but I can't figure out why the cards are twisting as the path moves up and down. Any ideas? I don't know if anyone will be able to open the attached .hipnc. It is of course made with the Apprentice version. cards.hipnc EDIT: Well about five minutes after posting this, I realized I could do what I wanted without the copy SOP. Just sweeping the card itself along curves now. I don't know if this affects how easy it will be to animate later down the line. But I guess I'll figure that out some other time.