ejr32123

@ikoon Thanks for the detailed answer- very helpful

There really isn't a "problem" it is more so trying to understand how collisions work. I am not trying to achieve a look or do some effect. I am just wondering how collisions work. Just trying to see if what I think is correct about collisions: 1. Takes the velocity from the collider and advects the smoke with it 2. Delete any density that goes inside collision object

It did talk about collisions for a paragraph or two, but its not clear to me. It does seem to indicate what I am thinking is true.

Hello, Could anyone explain exactly how pyro collisions work? In some cases, it doesn't seem like collisions with the smoke solver are "real" when using moving colliders. It seems like 2 things happen when using an animated static object: 1. Takes the velocity from the collider and advects the smoke with it 2. Delete any density that goes inside collision object (can be disabled) Look at my gif. If I disable velocity from the collision nothings happens. The density just gets deleted. In the example I turned off correct collisions for better visualization. If the collisions were "real", I would expect the density to move when the collider moves, then stop once the collider stops since no velocity from the collider is being applied. Any ideas? smoke_collision_test.hip

Here is a way of doing what atom said using point vop! hope this helps... particles.hip

I finally got it working, I had to set permissions to /opt with chown. I am a linux noob : )

I reinstalled it and now it's giving me this error.

Hello friends, I am trying to export from a mplay using ffmpeg. However, I keep getting this error (shown in photo). Any idea how to fix this? I am using Ubuntu 18.04 Thanks, ER

Could point deform work? Something like this: flip_remesh.hip

Well, I am not sure why the method above doesn't work but I found an solution: @stray = idtopoint(@OpInput2,@id); if (@stray != -1){ removepoint(0,@ptnum); } All the extra point from intput 1 receive a -1 because they don't exist in the second input. I can use that information to delete the strays.

Hello! Would someone mind telling me what I am doing wrong? I wanted to delete some points from a flip sim by id. I went to a frame where I could see all the points I wanted to delete, then dropped a timeshift and froze to that one frame. I grouped all the points I wanted to delete and then blasted not group. That gives me a static frame of all the points I want to delete. I created a point wrangle will all the flip points going into my 1st input and then the points I want to delete going into my 2nd input. In the wrangle I typed: if (@id == point(@OpInput2,"id",@ptnum)){ removepoint(0,@ptnum); } For some reason that is not working. If I change the first line from @ptnum to an actual point number like "23", then it works perfectly. Since I want to compare all the points I am putting @ptnum. What am I doing wrong? I also tried just adding a blast node with this as the group to delete: @id=`point("../blast1/",@ptnum,"id",0)` Thanks delete_by_id.hip

I think I found the answers to my problems. IT seems you create initial constraints at sop level. if you want to add other constraints at a later time in the simulation then you can add them in dops. As for animating the constraints, I just output my pressure constraint to a group called pressure. I use that group in my vellum constraint properties node to only affect pressure.

Hello! I had a few questions about vellum. Whats the benefit of creating constraints in sop vs. dop? Is it possible to setup vellum and only create the constrains at dop level? It seem strange to have to switch in and out of my dop net to change values. I seemed to be able to get most constraints working in dop, but it seems the cloth constraint needs to made at sop level. Also, how do I animate values? I see there is a vellum constraint property node, but how can I animate values for a pressure constraint? It seems like the constraints are created first frame and not updated. Thanks in advance.

Hello: I am trying to do something similar to this effect: https://www.youtube.com/watch?v=bUsIZEVfD0w Pop curve force works perfectly. I can force particles to stay within a certain radius of the curve. However, the gas curve force it does't matter what the suction force is, the smoke always goes away from the curve. I am trying to get this working with out emitting smoke from particles. Any ideas? Thanks test_curve.hiplc

I have had to do this before. I used a mixture of vops with ramps to fade density and vdb combine.