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Everything posted by revelationsr

  1. fluid emitter from particles

    Hi there. I have a little issue that is killing the look of my fluid simulation. I am making a dirt tornado. So I started off with simming a bunch of partcles in the shape I wanted with the intention of having them emit volumes for the pyro simulation. This all works. Giving me some great interesting shapes. All good. The issue is that the volume the particels make is sort of stamping itself into the pyro sim. instead of seeing just the nice pyro sim. I can see the particle emitting volume traviling within it as well. Put another way. The particle emits a volume denisty of 1. Forcing the pyro to have a volume denisty of 1. It obviously needs that because it needs to emit from that. But it is ugly. Is there a way where I can emit the denisty of 1 into the sim. But not have it visually show up within the sim. Maybe have it fade in for a few frames. Intead of having that value of 1 very obviously travel anround the tornado. Cheers
  2. wind tunnle smoke

    Hi there. I am making a wind tunnle smoke effect. One of those where multi small smoke sources in a line is running over a car. Originally I had a good looking effect with pyro. How ever the director wants a level of control over the shape the smoke makes that pyro simply wont do. So I have built a setup with several curves that the director can tweak and change as much as he likes. That is all working just fine. Then I run several thousand partciles along those curves. With all the attributes one would expect. My problem starts here. I would like to convert those particles into a fog. But I dont know the attributes needed to have control over the resulting fog. Things like. -Importing Alpha from particles. -stacking particles so the fog will be denser in areas where there are more particles. -importing the velocity from the particles for motion blur If you know of a place where I can find these kind of settings. Also any others that might be useful. Please let me know. Cheers
  3. wind tunnle smoke

    Oooo that is a very interesting link. I must go through that in detail. There is an interesting idea. Solve the smoke as straight and then deform it. Hmmm. Cheers for that.
  4. wind tunnle smoke

    Thank you I will have a look when I have a moment. Cheers But if anyone could maybe have a more direct answer that would be awesome. Much love to you bro. I just dont want people to think that this has been solved just yet.
  5. Hi there. I have an effect that triggers on a frame. This effect will happen on each primitive. I have an attribute on the primitive that says which frame the effect triggers. My problem is that I dont know how to change that attribute for each Primitive. Right now I have something like this. @effectTrigger = 10; The effect triggers for all primitives on frame 10. What I would like to know how to do is something like this. @effectTigger(PRIM number 0) = 10; @effectTigger(PRIM number 1) = 13; @effectTigger(PRIM number 2) = 23; @effectTigger(PRIM number 3) = 48; Cheers
  6. Set a value pre Primitive

    Awesome man! perfect! Cheers for that
  7. Hello. I would like to toy around with an idea of moviing partcles, which are repersenting cloud, to move around a sphere. The driving force would be a high and low pressure system. Basically a animated black and white noise. I would like the normal of a point on the sphere to push the particles. I just need to figure out how to get the current point to look at 10 or so of its neighbours and point the normal in the diection of the lowest value of the noise. I am sure I can do this with vops. I just dont know where to start looking. Cheers
  8. Hi there. I have a bunch of particles flouting around a forest scene. I am trying to only render out the particles. But the trees seems to always show up in the normal and Zdepth passes. I would like to know how I can render the particles such that they are masked out by the trees but not to then have those tree rendered in any of my passes. Cheers.
  9. render something with no alpha

    Hi. Yes I have tried that. Does not seem to do it.
  10. Hello there. I am new to houdini and have zero shader building experience. I am trying to build a shader that gives the look of ash on particles. I have a battle field scene with smoke and the likes flowing across it. So the particles needs to have random noise on it. This noise needs to effect the alpha as well. Then needs to fade off as it reaches the edge of the sphere relative to the camera. Cheers
  11. Hi there. I have a scene with several cached particle systems. When I send the scene off to the farm it creates IFDs. It seems to output the entire cached frame into the IFD. Making it take allot longer. Now my understanding was that checking the "delay load geometry" box in the "load from file" would make the IFD write out just a link to the cached geometry. This does not seem to happen. What am I missing? Cheers
  12. delay load when making IFDs

    Great thank you
  13. delay load when making IFDs

    Ok i have found the delay load procedural node. Assign that shader to my object and that seems to speed up the exporting HUGELY! How ever I now dont know how to add the shader I want to my particles because the "material" tab already has a shader on it. Any thoughts?
  14. Hi there. I have a scene with several cached particle systems. When I send the scene off to the farm it creates IFDs. It seems to output the entire cached particle system into the IFD. Making it take allot longer. Now my understanding was that checking the "delay load geometry" box in the "load from file" would make the IFD write out just a link to the cached geometry. This does not seem to happen. What am I missing? Cheers
  15. Setting up an interface

    Hello. I am busy setting up the controls on a subnet. There are two things I would like to be able to setup but I cant seem to find the help for it. 1 A ramp. I have a few ramps in my scene and I would like to have them in a custom interbface. I am just not sure what I need to link up and where. 2 Visibility toggle. I would like to be able to change the visibility flag in my setup. So when I press a button on my interface I can then see my setup at different stages. For example. See the points scattered on my object before I copy things to them. So I can better see what they are doing. Cheers
  16. HI there. I have a sphere that I put a bunch of random attributes on to. I promote these attributes to vertex. I alembiced it out. On the Maya side I can find the color on the vertex. IT is under "colorSet[0]" But I cant seem to find the rest of them. I dont know if my problem is on the houdini side or maya side. If someone could please talk me through it. Or point me to a good tut that covers it. Oddly enough that seems to be a hard topic to find a good explanation on. Cheers
  17. giant space cloud

    Good day. I am trying to make a space cloud. I was thinking of using particles for this. I have a simulation running which is not looking to bad for a starting point. But I have run into a few issues. Firstly I would like to group particles in the cloud and assign different shaders to them. This seems to not work for me. I assume that all I need to do is add a material node. Add in the groups and point them to a shader. Cleary I must be missing something. Works when I do it to a box. Secondly I would like some of the particles to light up the surrounding particles. This seems to not work. It works when I assign the same shader to a sphere and put it in the particles. But the same shader on the particles does not work. Any ideas? Also if someone has any general advice about doing this, hints and tips to make it look awesome. That would also be helpful. CHeers
  18. exporting alembic attributes to Maya

    Yes I see them as well. They just dont seem to do anything. I connect a vector to a vertex texture and I get nothing. This is why I dont know if I am missing something. Maybe the error is somewhere else. Like me exporting it from houdini? Any thoughts?
  19. exporting alembic attributes to Maya

    Thanx Peon. I will have a look again. Might be something I missed. There are so many dam data nodes in Maya. Would be easy to miss. But I think I gave it a good once over. I dont think I missed anything. Maybe the problem is somewhere else? Multi points of failure makes it hard to find where the problem is.
  20. Copy stamp for Chops

    Hi there. I have a sphere. I have put several points on there with scatter points. I have copy stamped a sphere onto those points. I would like to have those sphere change in scale on rare occasion. Kind of like vibrating but in scale. How can I go about setting up a "vibrating" animation and then have that animation randomly execute on a random sphere from time to time? If I am not mistaken I need to use copy in chops. But I cant seem to find a good tutorial on this. Any idea where I can find one. Unless I am heading in the wrong direction on this. Cheers
  21. Copy stamp for Chops

    Wow great replay. I am so going to try this out. Thank you so much man !
  22. Copy stamp for Chops

    Sorry man. I dont know what "template points" mean. Still new.
  23. Hi there. I am sure this is a simple question and maybe I am just to blind to see it. I have a few dozen curves in a group. These curves are of varying lengths and point numbers. I would like a add an attribute to each point on these curves. This attribute should be 1 on the first point and two on the second so on and so on for the first curve. The same for the second and third and so on. I suspect I need to do this with a for loop but I just don't know how to go about this. Cheers
  24. adding attribute to curves.

    That's great. Will try it soon. Thank you
  25. fluid to particles to volume rasterizer

    Hi there. I have a little issue with bittiness in my render. I have a scene with a fluid sim. This sim is then pushing some particles. So far so standard. The idea is to get a ink in water motion. But with a kind of solid render look. Think paint in water. When I convert the particels back to a volume using the volume rasterizer from particles. Those rogue particles that manage to get themselves away from the herd makes the converted volume look quite bitty. It there a way that I can convert this based off particle density? So if there are 5 particles in one voxel I get more density. Where there are one I get close to zero? Or maybe there is a way to cull particles that go rogue? If there is another completely different solution that I have not thought of that would be great. Cheers