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Everything posted by Atom

  1. Does anyone know if it is possible to change the light radius of the points you supply to a cloudlight? I tried providing @pscale, but it had no effect. I'd like to make the bright spots in my image, smaller. ap_cloud_light_041620.hiplc
  2. Problems with two FLIP objects colliding

    Inside the waterfall sim you are specifying the same sources under the initial tab and sourcing the volume. Instead, reference the ocean spectrum particles for the initial data and keep the waterfall particles for the sourcing. Remember to turn off Initialize Velocity on the FluidObject to start off with a calmer surface. NOTE: Your collision object does have some holes in it that are revealed at higher particle separation counts.
  3. FLIP Retiming jitter

    Try Retiming By Speed instead. Keep your input and output ranges equal, but change the speed value. I would Retime from the Suface Cache node, not the Compressed Cache node.
  4. Flipbook Export error

    Does your user name have special characters?
  5. flip-problem-help!

    You may want to try emit particles from the shark's surface, then you can focus more on the animation rather than collision and flip resolution. The shark fin is a challenge for the collision system. You may want to "thicken" it with modeling before you convert it to a VDB. There is an example file here that shows how to set it up. Another fun thing to do is to crash some free floating flip particles into the animated collider. Time the impact for the best result. At render time you can just mix them together.
  6. Pyro Sim

    Here is my rework of your scene. The low resolution pyro scene is on the left with the right being the upres for better quality. ap_bowling_pin_pyro_040920.hipnc
  7. Here is a slight fixup. You are right about the particle system reusing ptnum. This is caused by the "reaping" mechanism of the popnet. If you disable it, you can still use ptnum as id and manually "post-reap" the result after the copy takes place. This prevents the flicker. ap_Particle Copy example.hipnc
  8. GTX 1080 may be crashing sims?

    Yep, you're right, I forgot Grid Scale defaults to 2.0.
  9. GTX 1080 may be crashing sims?

    Let's see, if we do the math for 75x75x125 @ 0.075 = 1.666 billion voxels. With that much memory usage, your 1080 won't be of any use. For large simulations, such as what you have described, you may need to distribute it across multiple machines. As an 8 post user, however, I would recommend choosing reasonable settings that will fit within your physical memory. now you know what is too big, just make it smaller and scale it up later if you need to maintain that exact size. Here is the expression I used to come up with that large number. ch("../flipsolver1/limit_sizex")/ch("particlesep")*ch("../flipsolver1/limit_sizey")/ch("particlesep")*ch("../flipsolver1/limit_sizez")/ch("particlesep")
  10. I put together a fuel based version of the basic density based starter rocket launch scene. This scene includes a couple of additions, that I have seen posted, here on OdForum, including Fencer's smoke drag, based upon distance from origin, and hand drawn velocity curves to encourage the smoke to travel along the curve shape. The support nodes for the hand drawn velocity are shaded purple, in the DOP network. Play around with the fit values on the gas wrangle to alter damping. Increase popnet particle count to send more fuel into the system. Increase popnet life to make fuel linger, longer. ap_rocket_lift_off_fuel_based_090919.hiplc
  11. (Solved)Best way to fix normals?

    What about something like this..?
  12. I messed around with your scene, yesterday. In my settings I decided to ping pong the frames back and forth until the particle dies, this way you can extend the life of the particle. So you may have to revisit the frame counting code inside the wrangle to implement a one-shot die setup. I didn't get the file instancing fully working, but local object instancing is in place. I basically made 13 grids and a point wrangle constructs a path to each one based upon what frame it decided it needs to display. ap_rm_lops_sequence_particles.hiplc
  13. Procedural Robots

    Thanks for showing the setup. I was able to remake a simple version using the letters from the SONY logo as the armor parts.
  14. At that point, you might want to consider how you are going to render them. That affects the final technique. You also might need to answer the question "what does my particle display after it displays the final frame?" Is it dead after 13 frames? If so, match the life of the particle to the frame count based upon $FPS. You might want to try instancing. Life set to 0.5 @24fps. Another thing to try, is to leverage the just_born group. Drop down a PopWrangle inside your popnetwork and assign the frame each particle is born to an attribute. i@frame_born = int(@Frame); Then you can use that value, later to know how to start counting from the beginning of the sequence.
  15. Boat explosion

    Hmm... I don't know what it is, but I think a boat wouldn't blow up like that. Now a torpedo moving through the water and hitting the boat, makes more sense.
  16. trying a subway tunnel

    You could make a standard skinned tube and then use the technique at this thread to stretch a copy of each of your panel sections across the primitives of the tube.
  17. You can set the Operation of the divergence field to Subtract and the smoke will move away from the divergence field, instead of being drawn in. Upres on right. Animating the scale of the volume might not be the best approach. All that does is increase or decrease the value in the area of the divergence field. To expang and area, you might try want to animate the scale of the divergence field shape at the SOP level and leave the DOP scale set to a constant. That way, when you expand the size from zero and up, the field size area of effect will grow, not the strength. ap_UPRES_smoke_divergence_040220.hiplc
  18. A lot of that look is determined by collision objects. Add a ground plane and make your velocity point down. You can check out my fuel based rocket launch thread here.
  19. Sure, here you go. ap_test_smoke_divergence_040220.hiplc
  20. Hmm... That's Od. (rewind to clear old cache..?) Here is negative divergence using your scene. I made the attraction point, bigger and visualized it.
  21. I think divergence needs to be negative. Try changing your keyframe value from 20 to -20.
  22. Keyframing with Python seems buggy?

    It does look like you have some coding errors. Here is my fixup: node = hou.pwd() geo = node.geometry() # Add code to modify contents of geo. # Use drop down menu to select examples. # KEYFRAME 1 # set variables time1 = node.parm("time").eval() #node.evalAtTime("time") # get data of the font node keyframed_font_Node = hou.node('../font3') keyframed_font_textParm = keyframed_font_Node.parm('text') keyframed_font_textParm.deleteAllKeyframes() # create keyframe skeyframe = hou.StringKeyframe() skeyframe.setTime(time1) skeyframe.setExpression("\"Hi, it's %s now\"" % time1 , hou.exprLanguage.Python) # set keyframe keyframed_font_textParm.setKeyframe(skeyframe) # KEYFRAME 2 # set variables time2 = node.parm("time2").eval() #node.evalAtTime("time2") # create keyframe skeyframe = hou.StringKeyframe() skeyframe.setTime(time2) skeyframe.setExpression("\"Bye\"", hou.exprLanguage.Python) # set keyframe keyframed_font_textParm.setKeyframe(skeyframe)
  23. Yeah, Houdini on low end macs doesn't work. Buy another computer. Did you notice in your report that they system can not detect any vRAM.( Unknown VRAM )
  24. Use the fit function like this... This will give you a random switch between 0-3. Notice the -1 count on the maximum number. Set the maximum fit number to the number of inputs. fit01(rand($F),0,4)
  25. Flip Source From Points

    @Brickhouz: Did you check out the expert tips Noobini posted? It looks like Kevin Pinga suggests connecting a PopSource node directly to the sourcing input of the flip solver.