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Everything posted by Atom

  1. Pyro colour swirl mix

    Create a sphere and click on the Colored smoke shelft tool. Review the Operations for the sourcing of the various fields. Your sourcing operations don't match. Try Pull on vel and Blend on Cd.
  2. Here are my settings for Renderman 23.0. It assumes a default install on a Windows system. HOUDINI_PATH = "C:/ProgramData/Redshift/Plugins/Houdini/18.0.287;@/python2.7libs;&" HOUDINI_DEFAULT_RIB_RENDERER=prman23.0 RMANTREE="C:\Program Files\Pixar\RenderManProServer-23.0" RFHTREE="C:\Program Files\Pixar\RenderManForHoudini-23.0" RMAN_PROCEDURALPATH=$RFHTREE\18.0\openvdb;& HOUDINI_PATH=$RFHTREE\18.0;$HOUDINI_PATH;& PATH=$PATH;$RMANTREE\bin;& I also have the RMANTREE system environment variable set to. C:\Program Files\Pixar\RenderManProServer-23.0\
  3. Volume toon shader

    It looks like the Toon Color Shader no longer functions in Houdini 18. I get an Incomplete Asset Definition.
  4. Hair simulation grass helicopter landing

    Here is a slight addition. A downward smoke simulation to emulate ground dust kick up. ap_helicopter_dust_test_10.hipnc
  5. Particles do not move well

    Try changing the response on your PopCollision from Stop to Slide.
  6. Cook frame per thread

    Isn't that what TOPs is a about? Distributes single core process across frames.
  7. Atom's Video Tutorials

    I have put together a short video that demonstrates how to upres standard Houdini 18 smoke.
  8. Here's a recent link on this topic.
  9. Hair simulation grass helicopter landing

    Check out the Daily HIP website. You might be able to use the toroid velocity field. https://dailyhip.wordpress.com/2017/01/17/toroidal-velocity-volume/
  10. Fuel Based Rocket Launch

    I made an attempt at "upresing" this fuel based rocket launch. Treating the original file as the a low resolution simulation does allow me to enable OpenCL. The uprezed version is on the right. A 500,000 voxel low res source drives a 4,000,000 voxel upres. ap_upres_smoke_pyro_setup_032520.hiplc
  11. Pyro Simulation

    I tried upresing your sparse pyro example and I can't get the upres to work. Do you know if it is possible to upres a sparse pyro solution? The image on the right shows the result. I get some action, but the solver does not seem to solve, it only smears...? ap_upres_trail_pyro_source_bunker_002.hipnc
  12. pyro sim with timescale & retime sop issues

    Perhaps, try "upresing" it and supplying the f@timescale Detail attribute with a value of 10.0?
  13. That is pretty neat. Not really true collision detection, but it tracks a deformed surface OK.
  14. If you're using a dome light, try blurring the source image. Sometimes an HDRi can contribute to noise in a render.
  15. Hi All, I have been working on a python script that will tweak the rig generated by the .cmd file produced by mcbiovision. Specifically the Carnegie Mellon University Motion Builder BVH files. The script modifies the Carnegie Mellon University Motion Builder rig to allow extended functionality such as adjusting the length of various bone chains in the rig. The script also has a tool to mirror bone lengths from the left to the right side of the rig for symmetrical bone lengths. There is an origin offset control to align the start frame of a clip to the world origin. There are two preset bone configurations for male and female skeletons as well as full rotation control for most bones in the rig. I demonstrate the steps to capture/skin the mesh geometry and extend the capture ranges using the Auto Weights tool which is part of the script. I show how to extend the capture weights of each bone to achieve full deformation coverage. The end result is a fully skinned dancing person. The python script itself is based on the artists concept of stacking eight head lengths on top of one another to form the full adult human height. This total length is then divided up by percentage for the arm, leg, torso and head lengths. The script applies these percentage to the original bone lengths captured using the scripts Capture Bone Lengths button. The length sliders modify these percentages to allow for adjustable bone chain lengths. I put together a video to demonstrate it's use. ap_BVH_python_tweaker_tut_end.hiplc cmu_salsa_dance_mocap.zip
  16. Group in point wrangle

    Your loop does nothing to change groups. What it actually does is loop over every single point, for every single point (slow). Thus your resulting P.z is always going to be the 1+ the z value of the last point. NOTE: You can't change a point value in VEX, then loop over and fetch it again (other languages, yes. Houdini VEX, no). VEX supplies a pool of points upon entry, evaluates the change, and revises the pool of points upon exit. You typically don't need loops inside of wrangles unless your are running in Detail mode (which means execute this code only one time).
  17. It looks like it is there to me, try the link. The script is there, but not the tutorial. Vimeo capped my limit a while back.
  18. HI All, I was trying out the new H15 ragdoll system with a custom animated FBX rig. The walk cycle works fine but when I transition to the ragdoll, all the bones fall to the ground and disconnect from one another. In the video tutorials from SideFX this does not happen. It looks kind of like a bad melt job. Do bones need to be glued together somehow? fbx_ragdoll_issue.zip
  19. Volume strange result Redshift

    You can not manipulate the Emission gradient that way. There must always be a black chit on the far left 0.0 position of the gradient. That effectively masks out all that temperature noise. Lock that position down, then place a companion color chit next to it to achieve your look.
  20. Group in point wrangle

    There is no need to run over all the points. At the top of the wrangle, you can simply choose the group you have already created and run over only those points. That entire block of code can be reduced to a single line, if you run your wrangle over points. @P.z += 1;
  21. If you drop down a popgrains node in line with you other particle nodes, you can gain a small measure of particle separation. This can get you a few more frames before the particle finally overlap and produce intersecting geometry.
  22. I believe a material is embedded in the .rs proxy file, but the problem is pathing to any textures. You can override in the DCC, but pure procedural materials should transfer fine. Try a simple silver or plastic on your .rs proxy.
  23. Graphic Design Zipper?

    What might be a way to model something like this? I could see using an animated mask in a 2D comp program, but I wonder if there might be a way to actually model this so the airplane could pull back the orange grid?
  24. Pyro Simulation

    Try selecting the bottoms of all the pins. Move your mouse into the 3D viewport and press the S-KEY to enter that mode. After you have made the selection, add them to a group. Once you have a group, delete everything, except the points you selected in the group. Submit that piece of geo to the fuel creation, node.
  25. Smooth Pyro Dissolve

    One way is to control the temperature field. In this setup, two animation control the result . One is an animated Clip node, that removes the density from the source while the other is an attribute transfer node that grabs the newly transferred color and supplies it as temperature to the remaining clipped surface. The blend width of the attribute transfer is used to precede the clip, increasing the temperature ahead of it. Once the temperature is above zero, the smoke starts to rise. And the smoke only. ap_up_in_smoke_031420.hiplc