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  2. setting attributes that stick

    Thanks guys, I looked at those links, very helpful. Thank you.
  3. I turned " Match P Attribute "on, but it doesn't work.
  4. Today
  5. I still was unable to get decent randomisation and i wasnt the only one. Another groomer had the same problem, so he made a tool to replace it.
  6. Displacement mask in shader

    If you open up the Principled Shader with "Allow Editing of Contents", you have to look for a node called "displace1". The "scale" input of that node is where you put your mask. "Shift+7" shortcut will allow you to search for a node by name and highlight it.
  7. Add AOVs to ROP

    I recently did something like this but for a redshift ROP. What I did is that I just use the parm().set() function on that parameter, it acts just as a normal number parameter so you don't have to go the way of dealing with the whole getting a list of all the parms, adding an instance of a parm and then reapplying the new list of parms to the node. If you'd be interested you can have a poke at the shelf tool I made (assuming you are doing this with python): https://github.com/Underscoreus/Rs_AOV_Transfer Hope it can help
  8. [SOLVED] Vellum cloth attached to vellum hair issues

    no probs at all, if i throw enough darts...one might stick eventually.
  9. [SOLVED] Vellum cloth attached to vellum hair issues

    Sorry for bringing back this older thread, I just wanted to add a short addendum on how I was able to solve this issue in case others find them self in this pickle later on. So after some detective work, I found that the freakouts were caused by some constraints I had, attaching my vellum piece to a piece of deforming geometry (vellum attach to geometry constraint). If these constraints were not present the sim ran just fine. My substitute for these constraints were to simply animate my bottom piece to follow my deforming geometry using a point deform before configuring any of the vellum stuff and then when setting up vellum simply checking the "match animation" checkbox and setting the pin type to stopped. Then inside the vellum solver, using a pop wrangle to change the stopped attribute to 0 at a given frame to allow the sim to take over. One thing to be careful off when using this approach is that vellum creates an attribute called "fallback". I don't know what governs when it triggers and when it does not, but when it does, the sim will try to move your geometry back to the position described in the baseP attribute. For some reason it was triggering whenever my piece would hit the ground and the sim would try to send the piece back to the "rest" position. I simply solved this by adding another wrangle in the solver always setting "fallback" to 0 and it seems to have worked. Thanks for all the helpful advice given in this thread!
  10. Yesterday
  11. here is a simple example with Python, I attached an example: parm = hou.parm('/obj/geo1/sphere1/ty') # store all values in list values=[] for i in range(100): val = parm.evalAsFloatAtFrame(i) values.append(val) # remove parm expression parm.deleteAllKeyFrames() # set values from list to keyframes for i in range(100): myKey = hou.Keyframe() myKey.setFrame(i) myKey.setValue(values[i]) parm.setKeyframe(myKey) bake_keyframes.hipnc
  12. Hi ! I'm trying to replicate this tutorial : But i'm having trouble applying the displacement in the shader. It seems the tutorial was made with an older version of houdini and things have changed quite a bit since then. I managed to import the mask attribute in the shader but i'm stuck as to where should i put it. I did manage to do the displacement at SOP level but i'm lost in shader level... Any pointers ? Cheers ! pyrite.hipnc
  13. So after investigating more I think I have too much polygons and mantra crashes when calculating the displacement. The fluid is a poly soup with 2.4 millions points and I thought my computer will be able to render that easily. I turned off true displacement on the ocean shader and it's working nicely. Cheers, Edit : without true displacement, it's ugly as hell, and I've still not managed to fix the crash. If anyone has an idea about how to solve this, I'll be glad to read it
  14. Hey guys, I'm facing a problem when I want to render my extended ocean. Mantra crashes during the displacement creation process, and I'm pretty sure it's not an hardware issue (Ryzen 2700X, 64 gb ram). The output mesh is pretty bizarre : I have a surface created under the mesh when it should be flattened and so there should be no surface here : I dont know what's causing this, but I'm pretty sure that this makes mantra crashing everytime. I tried using a grid instead of the mesh and it's working. I think that what's causing this issue is that when I simulated the fluid there was no particle under the collider and so it results in this weird mesh, I'll try to simulate again with a larger particle layer to see if it solves something. Here are the meshing parameters : I can attach the file if needed but as there are heavy caches that needs to be calculated it may bothers when looking for the bug. Cheers,
  15. you CAN write the vex yourself every time if you want to, or if you feel lazy, just a Point SOP, preset Morph to 2nd input then you can have a controlled lerp amount.
  16. Offset time on Copy to Points

    That is really cool ! If you don't mind me asking, is it possible to use this on a PNG sequence to start the sequence from an attribute on each point ? Say I have animated a traditional spark and would like that sequence to be copied to points, and to play from it's first frame whenever a point has it's attribute changed or created ? I have been trying to find the answer to this for so long. I have learned several ways to do it with cached geometry, but just to apply it to a material/pngs I have been stumped for months. setprimintrinsic(0, "index", @ptnum, f@some_attribute, "add"); // this would offset the start of each copy by the value of f@some_attribute
  17. This seems to be a problem with the normals. If you add normals to the points with a normal or polyframe node before the copy to points they won't jump.
  18. If you don't need any of the other functionality of the attribute transfer node, it would be faster to use a wrangle: @P = @opinput1_P; (line into input 0, edit into input 1)
  19. Hi guys, I have a problem: I'm making a cream/chocolate whirpool in a flip tank, then I woul like to throw in some nuts. I put a custom velocity to generate the whirpoll but whe I turn on the viscosity in the solver a square appears (as you can see from the pics) and the fluid seems swirl around it. Any suggestions to get rid of that? Thanks in advantage.
  20. I have an imported character animation from abc. I would like to offset the animation to do FX. I have a centroid as that's all i need. I would like to bake that out as an animated curve so I can manually scale the inverse curve to my liking. I tried using a point() expression to get the transform channels into a transform node. I then tried baking the channels view the baking menu, but it crashed houdini. I'm guessing there's a proper way of doing this........ I heard people were using chops, but also that it was meant for exporting to unity or something? I don't need to export the animation curves to another software. I literally just need animation curves to edit in the animation curve editor. Thanks!
  21. And in your example, as distance between original points and displaced point is much greater than neighbour points distance, you also need to use source and destination groups.
  22. That is what the "Match P Attribute" checkbox is for.
  23. Hi; I tried to make some animation using CHOPs based on a tutorial from "Peter Quint" (https://www.youtube.com/watch?v=4tGCG5u1jwI), but I got some problems with the rotation, so as you can see in the image below, my box rotation jumps on some frames, and it's starting rotation is wrong! How can I fix it? Thanks for helping. CHOPs animation_01.hip
  24. Hey guys, Just to briefly explain what I'm trying to achieve, basically I want to emit continuously one kind of objet (cone) in one side of the scene and swap to a different geometry when these pass a certain point (say a hoop for example). Being a bit more specific, I want to emit RDB objects and convert them in water after they pass through the hoop so they splash when they hit the ground. Just attached a quick sketch. In my mind I have to create a DOP network with a pop source (done) where we emit the points. Separately, I would also have a different DOP where I simulate the water. I guess I would have to pass the velocity attribute from one to the other so the objects (now transformed into liquid) continue with the same trajectory and end up splashing on the ground. Well... I don't know how to swap between DOPs lol. I followed different tutorials and I know how to swap/load other dop after a specific frame (dopio+timeshift) but this only works when it's one object only. It doesn't when you are shooting objects constantly, doesn't it? Any help would be much appreciated! Thanks!
  25. Hello; I wonder why I can't transfer “P” attribute values, to second geometry, by “Attribute Transfer” SOP..!? Thanks for helping. Att_Transfer.hip
  26. On Growth and Form

    COlors and Chops
  27. Can I use the CHOP nodes to deform a line?

    Just use that on file that you Get from Sidefx forum phase=$T
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