Jump to content

Search the Community

Showing results for tags 'shader'.

More search options

  • Search By Tags

    Type tags separated by commas.
  • Search By Author

Content Type


  • General
    • Lounge/General chat
    • Education
    • Jobs
  • Houdini
    • General Houdini Questions
    • Effects
    • Modeling
    • Animation & Rigging
    • Lighting & Rendering
    • Compositing
    • Games
    • Tools (HDA's etc.)
  • Coders Corner
    • HDK : Houdini Development Kit
    • Scripting
    • Shaders
  • Art and Challenges
    • Finished Work
    • Work in Progress
    • VFX Challenge
    • Effects Challenge Archive
  • Systems and Other Applications
    • Other 3d Packages
    • Operating Systems
    • Hardware
    • Pipeline
  • od|force
    • Feedback, Suggestions, Bugs

Found 85 results

  1. Hello, This is not really a new topic, but I never found any convincing answer to it. Here is the scene : (i) a ground plane A which has a shadowmatte shader applied into it; (ii) a cube B that also has the same shadowmatte material applied to it and (iii) a volume having the form of a sphere C to which a billowysmoke material is applied (for fun, I could have taken a solid with a classic shader). I want B to cast shadows on C but not on A; I want simultaneously to have C to cast shadows on A. Said otherwise, I would like that all objects having the shadowmatte applied onto them cast and receive shadows onto / from objects having a different material, and avoid any "selfshadowing" ("self" being understood as objects having this same shader applied onto them) Therefore, saying B don't cast shadows don't work, neither saying A don't receive shadows. By the way, it seems that all masks options can't work in this situation, nor making groups. It seems to me that it would requires to change the code of the shader, so that when a ray hits a surface, it should "understand" what was the previous surface he was bouncing from and get its shader name, to know if ultimately it can be considered a shadow ray or not... Being quite weak in shading, I may express that very badly, but in short : does anyone knows any tricks to solve the problem above ? The only way I can get what I want is through having different passes / AOV with masks and solve that in comp. But a one shot solution would make gain some time :-) selfShadowingTest.hip
  2. Since new shading system matnetwork came out, do we a method to add AOVs without unlock a default shader, but can create it with combining a kind of layer-shader? If this is possible, it's so easy to add AOVs and no need to unlock shader could save file size, too. For instance, create a material builder and add AOVs like a particle RGB_mask in there, and create a sort of layer-combine shader, then connect the material builder shader and a principle shader into it, then output it to mantra.
  3. Interior Fluid Shader

    Hey wizards! I have a challenge I need help solving. I'm doing a flip sim where I have to mix two different fluids together, I.E. water and lets say molten aluminum. Clearly these two fluids need 2 different shaders, but when doing a sim you'd want one one mesh to keep everything clean without gaps or ips. I've already created a single shader driven by surface attributes to get the two different materials to work on the same mesh. There's only one massive, glaring issue with this method. You don't get any of your interior attributes back from your particles when using a mesh. The many solutions I've tried all fall short including using volume representations of the interior fluid, this is because a volume cannot receive lighting information that surfaces can I.E spec, refraction, SSS, etc. One idea that I haven't been able to fully explore, due to my lack of shading knowledge, is the way that ocean shaders use particle and volume data to create the deep ocean looks that Houdini is great at. So TLDR my question is: Is it possible to recreate a shader that works like the ocean shaders in that I can take volume and particle attributes to drive things like sss, spec, refraction, etc. using the principled shader. If so, if anyone has any basic leads or can point me in the right direction to get started that'd be huge. I really want to get this shader to look incredible so I can share it with the rest of the community down the road if anyone needed to tackle something similar. Have at it team!
  4. I'm trying to create a layered shader from two classic shaders. However, I noticed that the layered shader loses the point color and alpha information. Please refer to simplified example. The polygon sphere has varied point colors and Alpha. If you apply classicshader_A or classicshader_C, your see left side of the sphere is red, the right side is green, and the bottom is transparent. Which the material is inheriting from the point color and Alpha attributes. However, if you apply the layermix node, which combines the above classic shaders, you'll see the sphere changes to a solid pink, with solid alpha. How can I use the layer mix, while preserving point color and Alpha? What am I missing? thanks layeredShader.v01.hipnc
  5. shader help

    I am trying to figure out how to create a custom shader in vex for creating a glass shader with refraction for bending light. Additionally, i am trying to create a shader for lava that uses one shader when the temperate or speed is above a certain threshold. Like when it is flowing fast it uses the liquid lava shader and then switches over to the solid lava shader when the speed slows down. How can i achieve these shaders? I have been having some issues with creating these.
  6. Hi all, I'm confounded by a scenario and I'm hoping that someone else might have run across this. I have a light shader assigned to a Light Template object: let's call it myLight. It behaves as expected for non-motionblurred frames. But when I place it inside a subnetwork, put extreme motion in rotation and translation on the subnet, add a generic Light (spotlight) object to the subnet (at the same level as myLight), the generic light motionblurs properly but I get no motion blur my myLight's contribution. Here is the poignant code and information that I can tell: light myLight() { vector Plight = ptransform("space:light", Ps); Cl = max(0, 1-length(Plight*set(1,1,0))); } I am using Houdini 16.5 Mantra Raytrace mode. I am using exclusively xformational motion blur, 2 motion samples. I have the above light shader assigned to a Light Template object: myLight. myLight and a generic Houdini spotlight live in a subnet that has extreme translation and rotation animation. It behaves as expected for non-motionblurred frames, with and without rotational and translational transformations. It looks exactly the same with motionblur turned on, but the light from generic Houdini spotlight motionblurs properly in the same render. The vector version of the transformation, vtransform("space:light", -L); Seems to respect the translation component of the motion blur. BUT NOT the rotation component. So generally, myLight WILL motionblur, but not consistently in the right direction/magnitude. Weird. I have tried using the explicit path of the Light Template and to its containing subnet to see if I could jigger it. And the results are exactly the same: vector Plight = ptransform("/obj/mySubnet/myLight", Ps); vector Plight = ptransform("/obj/mySubnet", Ps); So I am wondering if I'm using the right transformation, the right variables, and if I am to add any special rendering intrinsics to the Light Template object to get the "space:light" transformation to respect the motion blur properly. What am I doing wrong?
  7. Hi there, I'm totally a noob using Houdini and I'm trying to figuring out how to achive this classic retro look. I can imagine there's some basic options ie: compositing some textures with the wireframes or creating thin polywires to create actual meshes for this edges. I also found this interesting post abut glowing points. I almost get to look I want playing with similar custom shaders, specially because I wanted to try with Nurbs in these lines, but of course it just deals with points, so I should somehow matte the grid faces itself to oclude edges behind other edges. It does make any sense this approach? Should I layer different shaders for the points or edge primitives and other one for the polygon faces itself? Would like to credit Thomas Helze for the FastGlow used in this tries above. Since this is a typical effect from all the times, I wanted also to know if anybody could just bring here some historical background about it, I'm feeling that the principles behind that look had changed a bit every time retro neon sci fi gets trendy again... And of course, please feel free to send me back to the QuickStart guides and all that... just wish you understand it's my first time posting here and you know, I'm feel like a totally stupid noob asking loud a stupid question at the end of a masterclass...
  8. Volumelight Fog Shader

    My open source solution to render volume light effects in Houdini Mantra based on the first part of this paper. Equiangular sampling (better sampling around light sources) Per-Light export Physically correct result Support for colored absorption (attenuation) Source code and example here https://github.com/somesanctus/volumelight
  9. Hi, I'm struggling to find the overall parameter to control the amount of displacement noise on the Classic Shader. I've got a custom attribute holding colour data and can easily plug this in to control the diffuse colour, refraction intensity, etc but where do i control the actual amount of displacement? Controlling the amplitude/turbulence doesn't seem to be enough. thanks.
  10. mandlebrot color issue

    i created a mandlebulb/mandlebrot and i want to animate it with colors that change like left 30% green right 70% blue and it changes over time. I do not know how to accomplish this. Please help. mandlebrot_016.hip
  11. A simple question perhaps - I am getting my head around the nodes representing "blend modes" in a shader: One of the most useful blend modes in Photoshop, Mari etc. is Overlay. How do you guys recreate "Overlay" in a node graph where you only have Add, Subtract, Multiply or Divide?
  12. Hello gents, I was pointed to these forums by one of our Houdini TDs. Myself I am a texture artist/3D generalist eagerly diving into Houdini for the first time (while being in a production, as it happens). My question: So I have a piece of terrain generated by the new Height Field nodes (see attached image). Lovely. What I want, is for the mask data (the red in the 3D viewport is an example of one of the masks based on height) to drive the shader live, not through a static exported image file. As I see this problem, how do I cross that divide (from the SOP (I guess) world to the SHOP (or is it VOP) world? One suggestion I have received was to use the Attribute Promote node, to sort of flag the data I want on the geometry side, and using a Bind node on the shader side to bring that data into the shader. In reality I haven't managed to make it work. There are around 18 different attributes on the bottom most nodes - which one to flag? Is it a data conversion type problem perhaps (trying to fit a round peg into a square hole)? Or do I need to bake the HeightField into actual geometry first perhaps? Or am I looking at this the wrong way around? I sincerely hope you can help...
  13. Hi all, I'm getting strange artifacts rendering a flip simulation with the PBR shader set to glass preset. As you can see there are lots of flickering and some features of the mesh even go in and out. If refractions are turned off the problem disappears, however the desired look is no longer achieved. The problem is not present on other presets such as gold, etc. Im guessing this has something to do with how the particlefluidsurface node meshed the sim, being inconsistent with the inner features or something like that. Is this a known issue or something anyone have come across? Can you think of anything to help me resolve it? Thanks in advance, Glass_Test_s.zip
  14. I have a small compositing network which I want to reference as texture in the shader using the op: expression .ie op:/img/trail Even though I've managed to make it work several times, I always find it a bit flaky and many times mantra doesn't manage to load the image, even though it may be visible on the viewport when referencing the same image operator in a uvquickshade node, or just by loading the shader. It works with a principle shader out of the box, but if I put the same shader within a material builder it breaks. Is there a render attribute or something else I need to add to the shader? I understand it's better to use pre-rendered images the normal way, but I want to use dynamic heighfields SOPs for textures and ideally avoid having to write out thousands of frames in advanced.
  15. Edge Dispalcement Shader

    With the new tutorial I am trying to somehow get this to work with default mantra, like the original tutorial, But i have some issues, hoping someone will point me in the right direction. I have attached the hip file here hoping someone will download, and correct it and show me how its to be done correctly for mantra. EdgeDisplacement_01.hiplc
  16. Hello!I am having a few bugs with the houdini toon shader.In some scenes it appears as though there are two objs on top of each other and intersecting, when there is not. Also, some parts of the model are just black under lighting while others are not.Has anyone come across this? If so does anyone know any ways to fix this? Thanks
  17. Procedural Veins material?

    Hey guys, I don't have a lot of experience in SHOPs yet so I'd like to see if someone could give me some ideas for this. I'm developing a procedural eye and I'm able to do it's veins procedurally on SOPs but I guess it would be much more useful if I could achieve something in the shader, maybe using some kind of noise. I don't know. I'm kinda stucked in the beggining so I just need any kind of ideas here's a good reference (I like the thickness variation)
  18. Hello! I am trying to create a shader with the Arnold VOP network that is comparable to the ocean volume mantra creates when the ocean toolkit is used. I have Arnold experience, but am having a hard time finding resources related to rendering volumes with Arnold (that are free, I'm a student on a budget). Any help would be appreciated, thank you!
  19. Flip rendering

    Hello everyone, I'm beginner in water simulation and I would like some tips if it's possible. For the simulation part, I'm not in trouble for the moment, but the rendering it's another thing. I'm trying to make an ocean flip simulation of a submarine going out of water, for the ocean shader, I have something pretty good now with ocean spectra and the ocean shader of houdini 16. The problem is the whitewater, for the ocean surface (the flip mesh) I don't know how to do the white part like in the sreenshot, is it particles, or tweaking the shader with velocity or vorticity, but which parameter in the shader (refraction?) ? And for the foam, spray, bubbles , I have to render simple particles or do another thing? Thank's for your help, I want to learn water, it's very fun to do! I let the breakdown of the screenshot here
  20. Hello! I can't get to work the new ocean surface setup, even with the provided scene files. I the viewport it's seems fine, but it renders flat. (and without the foam) Yes, I baked the spectra node. Can anyone point me in the right direction? There is none learning material about the new ocean surface, not a single tutorial, only the masterclass. Thanks
  21. I almost never rendered with Houdini but thought of giving it a try... Essentially I created an Octane material and applied it to my geometry but I want the diffuse colour of the shader to be the colour of my points geometry (and not the colour selected in the shader node). Im assuming it's a pretty basic thing but couldnt find a way to do it (played with material override etc.) ... maybe Mantra gets it automatically (seems a sensible thing) but not Octane. In layman's terms I coloured a series of geometries using some gradients and random values (my points have @Cd attributes). Then I created a standard Glossy Octane material. I want my objects to have the properties of the Octane shader (reflection, roughness, opacity, ...) but use the @Cd attributes in the geometry to drive the diffuse colour. Thanks!
  22. Hey guys, I'm new to mantra, made a material and I'm trying to animate, for example changing te offset on the noise or the displacement amount, but seems not having effect (i'm renering in mplay), also tried promoting parameters with no luck. Displacement says: cannot have channels wich depend on time Also Im trying to get the artifacts out, added some dicing to geo node as well as in rop, should I increase more? Thanks! mantratestanim.hipnc
  23. Guys, I guess it might be a veeery silly question but I just can't do it. How do I display textures on viewport? In this case I have this ramp applied (not an image texture) Thx! Alvaro
  24. Hello all, I am trying to figure out how to create a procedural shader that looks like sand (Applied to geometry, not particles) Are there any posts that you guys can point me to that would help me know where to start? Thank you Sand shader for dunes_v01.hip
  25. Hi guys I recently created a free asset to test shaders in a consistent environment regardless of the scene I am. I am kind of old school and feel a consistent shading testing area is very comfortable to create different shaders. The idea is that no matter what complex scene you are in, you can just bring this asset and then test render shaders on a tri light set up with background and env. light. The asset itself is very flexible. multiple shapes test, and grid or plain background. You can even bring your own object or shader ball into the scene. You can find the asset here: https://www.orbolt.com/asset/Butachan::nh_shadertest::1.0 Please read the instruction as I made the asset object, light camera, and actually everything invisible in the scene so it doesn't really clutter the scene you are working. I also made it open because as it is a render related asset I feel it will need some tweeking here and there to adapt to your needs. Bests, Nico.