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Everything posted by Atom

  1. Sure, change each of the FileCache nodes from No Operation, to Write Files. Make sure to move the blue Display flag to surface_cache node. Rewind and play the time line. You might want to set the timeline to "Play Once" instead of "Loop" Also: it looks like you are visualizing the collision object, turn that off, or you will waste memory creating that VDB for the display, every frame.
  2. I'm not sure if i@id is valid, try @ptnum. The id can be recycled, if you have reaping enabled.
  3. Bend Pyro Import!

    Here is a single pyro simulation randomly rotated and randomly retimed along random length paths that are randomly deformed. ap_path_grid_pyro_volume_093019.hiplc
  4. Bend Pyro Import!

    I'm trying to use the SOP Bend node to bend the results of a pyro simulation. I have a basic setup, that is close, but I don't know how to apply the new, bent bounding area to the existing pyro. This results in the pyro being clipped. Is there a way to expand this box based upon the new bent area? ap_bend_pyro_volume_092819.hiplc
  5. Bend Pyro Import!

    I made some progress on bending the pyro along a path. Extreme bends in the curve, reveal the rasterization, however. I pulled in a path deform subnet that I found at this link. ap_path_pyro_volume_093019.hiplc
  6. Bend Pyro Import!

    Yep, that's me on BA, too. I've been looking at the new 2.8 offerings, Eevee. Thanks for the file. I am still getting up to speed, with volume wrangles and your example helps. I have extended the wrangle, to include the temperature and heat fields as well. I think it might even be possible to replace the bend with a point deform and send the entire simulation down a path. ap_bend_pyro_volume2_092819.hiplc
  7. Generating volumetrail from moving points?

    Got some help on Discord. ap_toad_trails_for_atom.hiplc
  8. I have a set of points that define a shape. I wan to turn that into a velocity field that I can advect points through. I have a basic setup, but I can't figure out how to bend the red lines along the curved particle generated line. ap_particle_sphere_arcs.hiplc
  9. Avoid too heavy FLIP pull effect

    Setting the Grid Scale to 1, it defaults to 2, helps preserve volume. Under Volume Motion/Collision tab try setting the Velocity Scale to 0. ap_flip_car_drop.hiplc
  10. I'm not sure if you can create nodes, with vex, but you can with python. Here is a link to a script that scans a folder for images, creates a plane and assigns a material that points to the image. Maybe you can review it for tips on how to proceed.
  11. Hi All, I have a python node that I have added a button to that nodes user interface. I want the button to call a def inside the python script of the self node. I use the code from the help file but it does not work. Code in button: kwargs['node'].hdaModule().onButtonPress() Code in script: def onButtonPress(): print "click" What more do I need to make this work?
  12. Open CL

    How do I get my text that big?
  13. House fire sourcing Pyro

    This thread is a couple of years old, but you could check it out.
  14. Fuel Based Rocket Launch

    You'd think so, but in my experience, it does not all work by default. I wonder why they created the node (gasenforceboundary)...? Open CL is memory bound and can fail in high memory usage scenarios. (Depends upon your hardware)
  15. Random Sequence jpg to each grid

    Before you store them on as the attribute, you might want to use one of the various .eval() methods to resolve the path, instead of using the .unexpandedString(). Check out the Value section. https://www.sidefx.com/docs/houdini/hom/hou/Parm.html
  16. Merging BVH files manually

    What I have done, in the past, is to not bother with editing BVH, at all. Just blendShape the resulting two rigs. The length of frames that the blend takes, can smooth the jumping. If you blend, when the two BVH states are in a similar pose (use timeOffset node to match the incoming second BVH pose to the outgoing first BVH), the result can be nearly seamless. Do you know about BVH Hacker?
  17. Post Processing An Export?

    HI All, I am trying to add the usemtl tag after every group inside a OBJ file that the ROP Output generates. The Houdini exporter does not seem to support this feature of the OBJ file format. This simple fixup script does the job ok. # Add a default material for each group. # Run after .OBJ export. file_name_in = r"C:\Users\Developer\Desktop\my_mesh.obj" file_name_out = r"C:\Users\Developer\Desktop\my_mesh_mat.obj" with open(file_name_in, 'r') as f: lines = f.read().splitlines() # Remove slash n character at the end of each line. f.close() mat_count=1 new_lines = [] for line in lines: new_lines.append(line) ary = line.split(' ') if ary[0] == 'g': # Detected a goup. mat_name = "mat_%d" % mat_count mat_count +=1 new_lines.append("usemtl %s" % mat_name) f = open(file_name_out, 'w') for line in new_lines: f.write("%s\n" % line) f.close() So the question is how do I leverage the PostFrame Script event of the ROP Output node? I would need to somehow pass the frame # to the script. I have never used args* in python yet. Does anyone have tips on how to accomplish this task? Thanks
  18. I made an attempt at modernizing the FOREACH loops in that scene. You can check out the revised file, here:
  19. copy/stamp, alternative ways?

    Here is the basic "fake" stamp that evolved after CopyToPoints nodes was released. If you run it, inside a FOREACH loop, you can reliably fetch attributes from point #0. This image shows the standard point instancing technique, which is faster than the CopyToPoints, fake stamp. The main reason you might still want to use CopyToPoints, is if you are generating geometry that you need to export. ap_fake_stamp_090619.hiplc
  20. What I have done before is to pre-generate the start and end frame, then only generate a valid s@instancefile, when I am within that frame range. Use a null based geo file to reference in all other cases. if((@Frame>@start) && (@Frame<@end)){ int current_frame = @Frame-@start; s@instancefile = sprintf("myfile_%02d.rs",current_frame); } else { s@instancefile = "my_blank.rs"; }
  21. Issue performing if statement on an array

    I have found that the exact comparison between two float values in Houdini can sometimes fail. Try revising your detection IF statement to be more of a threshold, or close to the mark type of detection. float threshold = 0.04; //ch("threshold") or add slider. if(abs(APC-@Cd.x) > threshold ) { //Different. } else { // Close enough. }
  22. Issue performing if statement on an array

    I wonder if VEX is failing on the setpointgroup, because you have two different styles of quotes? Try double quoting set.
  23. Redshift issue with pyrofx

    You have to leave black on the left side of the ramp.
  24. importing Cops images

    There are some COP width/height limits when using Apprentice. Try using a test image that fits within the 1920x1080 specs for Apprentice.
  25. growing line effects

    One technique for making a line out of a particle is to use the Add node to construct a line, based upon the @id of the particle. All trails inherit this @id, so you can build a line by conecting all points that have the same @id. ap_brain_wire_glow.hiplc