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Showing most liked content on 02/13/2017 in all areas

  1. 7 points
    Hey guys! Here's my latest short called REACTION that I've been working on and off with for a couple of months. Enjoy! All Houdini and rendered with Octane
  2. 4 points
    Yeah so I'm still playing with bricks, I'm definitely a square. Nothing fancy, the hardest part was data swapping between different sims.
  3. 2 points
  4. 1 point
    relbbox() requires geometry file to work on, it will not pick up geometry that's being shaded, so if your object is delay loaded, you can promote file input to the shader and put the same geometry file in there, if not, you'll have to export geometry to the file to reference in the shader or you can pre-compute relbbox as an attribute in SOPs and bind that in the shader
  5. 1 point
    Nice! Renders look really clean and crisp.
  6. 1 point
    In that case, try closing the "Scene View" tab and create a new one, that usually helps if it keeps rendering objects that it should not render (because of hide settings for instance)
  7. 1 point
    the "zigzags" in the trails are the result of vectors pointing into opposite directions and this is due the way how they are calculated. when you calculate the eigenvectors of the matrix there is no easy way to determine in which direction (+ or -) the vector is pointing because both directions are true. an easy way to handle this problem is to check and reverse neighbouring vectors recursively, starting from one point, or write your own streamline algorithm in vex which ignores opposite vectors based on a given threshold. either way, this is not be a perfect solution but depending on your needs it might be enough. if you want a vectorfield on the mesh which is as smooth as possible, then that´s a completely different story and it becomes much more complicated... in regards to your other question, if you need to fully understand all the things in the file, i would say no. it´s nice and sometimes helpful if you do but this is something you´ll barely need for day to day work. but that is just a personal opinion based on personal experience and not an advice by any means. hth. petz
  8. 1 point
    I saw the Lego movie recently and thought I'd have a crack at their point cloud sims. As it stands, all the bricks are the same size so I'm trying to work out how to randomize those. Fun stuff!
  9. 1 point
    increase bullet solver substeps (default is just 10)
  10. 1 point
    Awww i see, looks real nice man! Ive just put together a quick file, using literally off the shelf tools - dive in and take a look its pretty self explanatory i think - but its how i approach it anyway, - you could also add a wave layer tank from the off the shelf tools for nicer whitewater on the ocean rather than using the foam within the ocean shader. (So my process would be render the ocean surface at whatever size it needs to be and then simulate the small area using the splash tank for interaction of that - merge that into the mesh off the ocean surface using VDB's - Or another technique ive seen is deleting parts of the water mesh and whitewater based on position and velocity leaving you with just the outer or 'surface' whitewater and splashes which you can then combine with your ocean surface and other elements) or just render them both and combine in comp carefully. Hope this helps Ocean_seamless_file.hip
  11. 1 point
    And 72 hours later I have a new surface cache at 0.02 particle separation using the surfacing recipe I mentioned above. @Chris: I am not combining anything, I took the make it all in one big sim route. I don't really know how to combine two or more fluid simulations in a Houdini-centric fashion, but I was hoping someone might have an example file they could post? The speed boat example would be great.
  12. 1 point
    From my small research on the topic, making decal is trivial. Transform shading P into decal projector object space and use it as UVs. Then you will get decal's color and alpha. However, you cannot place decal projectors and project materials onto another materials: They will not receive decals. You need to dive and unlock, then modify each scene shader to make it do such thing. Therefore you cannot efficiently use decals in Houdini. At least, without writing some Python tools. If you want to use your own shader for procedural texturing and project decals only on it, it is simpler task. Here is my tries to make in more or less usable: decals.hipnc Single texture blending was used, but it may be full material layer blended with main shader using Layer Mix node. Which is what you usually expect from decals.
  13. 1 point
    A bit of progress with this bad boy
  14. 1 point
    Hi All, I am trying to visualize the relationship between some of the FLIP parameters on the FlipObject and the FlipSolver. These tests are conducted on the default network create by the shelf tools. Only the parameters listed in each image have been changed. Overall I think I like a higher Particle Radius Scale, locking in on 4.0 up from the 1.2 default. It seems like the fluid clings to the surface of the collision object in a more natural way with a particle radius scale of 4.0. If you want to thin out the fluid subtract 1 from the Particles Per Voxel expression in the FlipSolver Reseeding tab. ceil(pow(ch("../flipfluidobject1/gridscale"), 3))-1 If you want to thicken your fluid add one to the above expression. If you add more than 1 you can introduce a nice churning effect. ap_3_sphere_flip_test.hipnc
  15. 1 point
    attached is a file with all sorts of curvature computation for vdbs ... hth. petz vdb_curvature.hipnc
  16. 1 point
    You can also add a Viewport Comment parameter to the camera, with $F in it: Parm dialog (gear) menu: Edit Rendering Parameter > Viewport Display > OpenGL View > Viewport Comment.
  17. 1 point
    Thanks everyone! I had some time to work on this a little bit more. So I refreshed the video file. Now it also has a bonus fancy closeshot xD Also I cleaned up my asset and want to share it with you guys. So what is it: Feather system based on wire dynamic simulation. Originally it was based on the fur system but now there is only few nodes left from it. It also has cloth-like behavior to make animation smoother. you can: - paint attributes such as comb, length, density,texture blending. - texture each feather, color all of them using skin texture. - blend multiple feather textures together - ruffle feathers, mystique effect. - supports custom imported curves. For example I created some curves in blender and used them to drive feathers. Some issues for now: - it intersects. Because it is not a cloth sim but the wire sim feathers doesn't know about their neighbors so they can intersect. However when there are a lot of feathers and they all have proper alpha texture you won't see it much. - mystique effect needs to be polished. Just need to add ramp parameter to control bending. Also I want to share it on orbolt. So I would like u to test it and say what do you think. Owly_feathers.zip
  18. 1 point
    HIP DOP_BendConstraint_v01_SIMPLE.hipnc
  19. 1 point
    No worries. I'd say don't worry about it. Shader writing is complex and there's a lot of other things you have to worry about before you start thinking of creating your own shaders. You can get far with the Mantra Material Shader, learn from the help and have a gander around the nodes (when you know what you're looking for, ie, adding a second layer of spec, which is built in, but not activated on the shader interface). That way you can build up slowly, just getting used to what you want something to look like, rather than the maths behind it. When you're starting to ask more complex questions about how the light is interacting with the surface, then you can start looking at old siggraph papers I've recently gone to the effort of writing a few of my own shaders for specific situations and now feel happy jumping in and starting from scratch, but it was messing with my head at the beginning.
  20. 1 point
    The surface position (P) from the global variables in a shading VOP is actually camera space, not world space. This throws a lot of people off, myself included.
  21. 1 point
    The Rest SOP adds a rest attribute which is hopefully represents the position of the geometry at a non-deforming rest. You need to have a shader that uses the rest attribute in place of P. Supermaterial handles rest by the way. Given what you are doing though, I suspect you don't need a rest but to generate your uv's on a static piece of geometry. In your specific case, applying the uv's before the twist should do it. The only time you need rest is if you have a shader that utilizes P as in point position in procedural shaders such as a granite material that uses noise based on the point positions. Use rest instead of P in this specific case. Rest is not applicable to anything else really. Just shaders that use geometry position instead of uv's (st's). As for any texture maps that rely on uv's, rest is not at all relavent. If you are using uv's and your material is sliding, you need to move the uv's up the SOP chain where the geometry does not deform. If this is not possible because you are reading a sequence of deforming geometry off disk or other reasons, then fork off a SOP from the current chain, lock it and apply your uv's to this. Then with a point SOP for point uv's or a vertex SOP for vertex uv's pass this locked and uv'ed geometry to the right input and in the left your deforming geometry. Now for the texture parameter in either the point or vertex SOP, use $MAPU2 $MAPV2 and $MAPW2. Now this is only a last ditch save. It is best to naturally apply the uv's to a static model before any deformations. Hope that helps you out.