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Found 105 results

  1. Keeping displacement using rest pos

    Hello all, I have a simple question after trying hard and also looking into the web and SFX help cards with no success... I have a simple quad mesh with unshared edges, then I connect that to a rest sop, pipe that into a bend sop for deformation and connect that to an attribute vop where I use an anti-alias noise to create displacement on the model. After the part is bent and with displacement applied, I would like to have it back to its original shape before the bend but keeping the displacement intact. I'm doing that as a way to have more control over the noise transformation. Tried using a wrangle sop with @P = @rest; but "duh" enough.... the part comes back to the rest position and the displacement is gone. If I try that same procedure with Cd instead of displacement, it works. Does anyone knows how to get the mesh back to its original shape after the deformation and displacement were applied to it? @mestela mentioned this in his amazing cgwiki page, something like this: Measure deformation Can measure the distance between @P and rest with a wrangle like @d = distance(@P, @rest); And use that to colour the surface, or enable a displacement map to drive wrinkles, or push points along their normal to do hacky squash and stretch. However, I don't have a clue on how to keep the displacement after the deformation and back to its original shape. Any help is greatly appreciated.
  2. is there anyone to know the workflow of pcopen and iterate with new houdini version?
  3. in depth tutorial for point cloud in vops

    Hey guys , I need a good resource to learn point cloud in vops with basic examples , Plz help me Best regards.
  4. Hi Odforcers, does anyone know how to wire the 'fake caustics' VOP inside mat builder? (apart from using the principled shader, tx)
  5. While loop in VOP

    how does while loop work in VOP?
  6. invert exponential

    how can I invert exponential in attributeVOP?
  7. Verify that pcclose() is called

    why it gives me this error? and how to solve that?
  8. Array in VOP

    is there any guide to work with array nodes in VOP? I used for loop to do the job but the result was odd
  9. Look at inside attribte VOP

    is there anyone who knows how look at works inside attribute VOP?
  10. i am working on the firework effect. i emitted some particle by pop locate and they replicate some particles when dead. Each original particle has orginal id and the id is inherited to replicated particles. What i want to do is assign the normal vector of Geometry( sphere) to the velocity of replicated particles and adjust them along the each original id. so i decided to iterate over original id with For loop inside popnet. I made array list of original id and each id inside the array is taken by Find attribute value count and again loop over with the count of point number that has each id on the array list. The point number that has certain id is bringing into the list called "plis" but the list is updating and deleting,adding new pointnumber. It is not accumulating. how can i fix this ? - my array isn't accumulating but adding one point number and updating the others repeatedly. and Do i complicate the process to make little bit simple effect ?
  11. Add primitive in VOP

    does anyone know how the add primitive workflow is inside the attribueVOP?
  12. as you can see in image below , I want make the i1 (index) incremenal with VOP for loop . how's the workflow , please show me with another simple sample.
  13. Bulginga spere with Vops

    Hi have been trying to flat bottom or top a sphere with min max bounds in vops with a ramp and a fit. Its not working as want it to. I'm not being able to interpret to Houdini how to interpolate between top bulge and a bottom bulge. I aim to execute this in a procedural way. I need help!
  14. Finished my first tutorial, hopefully you find it helpful learning Houdini!
  15. How to add color gradient through velocity plus collision to influence color velocity? to influence the color such as this one here: https://vimeo.com/59024762 how did he do, but he used xsi softimage. if possible to make a Houdini?
  16. Hi, I'm trying to add noise to this curve falloff animation. Currently it's just going straight to the bottom. I want to add a little bit of noise to it. I have used resample node to generate curveu attribute. Can anyone please help me? I've attached the scene file. curveu_noise.hip
  17. In the file I try to create the custom velocity with noise over time using normals. At first I did it with AttributeNoise, things go smoothly. Then I try to recreate it with Vop node, I can't have the normal distribute equally in all the direction like how I did with AttrNoise. Plus it move very fast over time, how do I reduce the movement of it. Also, can anyone show me how to do it in vex too. I add @Frame in vex, everything move in super speed. Thanks in advance. customVelocity.hip
  18. Hello, I have a few questions about vop nodes in mat context. I have no trouble with vops in sop, but things seem to fall apart in /mat (FYI I am working inside a material builder). 1. Is it possible to access @ptnum and @primnum? It doesn't seem to work 2. Some binds just don't seem to work. If I do the same bind in /obj vop context, it works perfectly, but binding it in /mat material builder doesn't. Why would it not work in the /mat context when the nodes are the same? 3. If the vop asks for a file and I use op: to get data from a node in /obj, it does not work and says error finding geometry. But if I do the same thing in /obj in a vop network, it works perfectly fine 4. In /obj in a vopnetwork, you can access the input from the geometry vop global parameter node. If the vop node asks for a file, you can wire it into opinput 1. How do you do that in /mat? What if I want to access the geometry to which the shader is applied? It's asking for a file, but I just want to use the geometry to which that shader is applied. Thanks
  19. Hello, So you know the import point attribute in vops? It asks for a file, right? Well I give it a file in my first photo and it prints no data and the color comes out black. That makes no sense at all. In the second photo I loaded that very same file using a file sop and plugged it into the second input of the vopnet, but in the import point attribute I used "Second input" instead of "file" and it works. Why is that? It's literally looking to the same file. Thanks in advance.
  20. Learning Houdini on Twitch.tv

    Hello! I'm starting a twitch dot television channel and will be streaming Houdini training content. I've worked at several large VFX and advertising studios as well as taught Houdini classes at Academy of Art university. I'm hoping I can reach a larger audience through Twitch as well as the idea that people viewing the stream can participate by asking questions and providing feedback in real time. This is my channel: https://www.twitch.tv/johnkunz My first stream will be starting on Sunday (Jan 26th) @ 1pm PST. If you follow my channel (it's free ), you'll get an email notification whenever I start a stream. I'll be going over this project I recently finished https://www.behance.net/gallery/90705071/Geometric-Landscapes showing how I built things (VOPs, packed prims, Redshift render) and why I set things up the way I did. Some of the images I made are shown below. Please come by this Sunday with any questions or ideas you might have!
  21. Trying to find some info on applying quaternion rotations without using the copytopoints @orient point attribute. I build my quaternion, and then I'm stuck on doing two things: -Applying the rotation to an unpacked object and a packed object I've tried the rotate by quaternion VOP with unpacked geo and the makeinstancexform for packed geo and nothing seems to work this way... I've done some research but didn't find anything usefull (outside of copytopoints @orient). Can some one point me in the right direction?
  22. Hello! Thanks in advance for the help... I have an alembic object that is animated, and I have added a VOP Noise node to stylize it. The problem is that th enoise is setted up at world scale, and when the geometry moves, it doesn't have the noise pattern stuck onto it. I would need the noise to be in object space, and I don't know how to set it up. I've been doing research for days and I've com across to a posible solution, but it is not 100% exact. I have attached some pics of the current setup and where it is giving me some errors. Thanks!
  23. Hi all, I've been practicing and experimenting with VEX in Houdini and I challenged myself to see how far I can go with only VEX and VOP. I did successfully manage to create this simple effect without any use of dynamic simulation (DOP). https://vimeo.com/375250070 Basic Summary: A particle system that computes at frame-basis. I can jump from frame 1 to 700 without waiting for simulation. Instead of the traditional age/life computation, this system uses travel speed to compute. Trajectory generated with polar coordinate + Flow Noise on sphere section. The graph mainly consist of VEXs. There's still room to be improved definitely, if anyone is building more upon this, please share it, would love to see it. I think at the end of the day, this kind of system is probably not entirely practical tbh, but it's a great practice and study on coding with VEX. (SHOUTOUT to a best friend of mine who's studying mechanical engineering, helped me to find a way to calculate the spiral length.) HIP file here: FX_Rasengan_v01.hipnc Happy Coding!
  24. Hello, Can you please help me a little bit? I would like to animate the direction of my normals based on the anti aliased flow noise in point vop. Can you tell me which nodes should I use to get this result? Thank you
  25. Custom Velocity with Volume VOP

    Hello there, I'm making a classic Ship Sailing Effects (ocean guided). I'd like to add a custom velocity to the bow of the ship in order for me to have a good turbolence like this: Through a Volume VOP (please see the hip attached) I created the following velocity: The shape I had it's what I want (straight velocity to the front and curved ones along the sides of the ship, so they can push the water for having a classic V shape). However, I'd like to invert the value of it: having higher velocity in the center e gradually less on the side. With my solution I have to much velocity on the side and less on the center of the bow. Basically I need the trails to be red (high) at Z=0 and blue (low) at the Max Z bbox. Furthermore, is my solution right? I blast a part of the bow, scattered it and then use a Volume Rasterize Attributes for creating the velocity. And, lastly, what kind of operation do I need to use in DOP in Volume Source? Somebody says "Add", somebody "Pull". What is the correct way? I hope you can help me. Any suggestion will be really appreciated. Ship_Body.obj Ship_Custom_Velocity.hipnc
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