Jump to content


  • Content count

  • Donations

    0.00 CAD 
  • Joined

  • Last visited

Everything posted by marque_pierre

  1. Mantra transparency

    I have had the exact same problem. The best solution I found (although certainly still not quite where I wanted it to be) was to build my own shader instead of using the glass shader preset. So add a material builder node and inside that add the classic shader core. In the classic shader core, turn down diffuse and reflection completely. Basically you only want that for the refraction (the IOR is in the settings tab, should you need to change it). Then add a PBR Reflect node for your reflection - daisy chain style. And you are good to go. Looking something like the attachment. This barebones shader was put together by one of our guys to deal with glass windows that would render with so much noise. So, it can do that too...
  2. Hello folks, After enjoying myself immensely shading in Mantra (Kursk and Angel Has Fallen) for two years, I now find myself in a new Houdini situation: Arnold. Why Arnold? It is one of those situations where multiple vendors are handling the same assets, so my hands are tied here. Anyway, I have no end of trouble getting Arnold to render my textures. Primitives or existing geometry assets can be shaded and lit, but once textures are added to the mix... nothing (that is they render black as that is the missing textures colour). I must be missing something painfully obvious. My best guess is that Arnold somehow doesn't automatically pick up the UVs of the primitives or other imported geometry, because if I add a UV texture node to my box primitive, I can get textures on it. But the primitives' native UV layout is lost (or never activated). So... who can be the man of the hour and point me in the right direction?
  3. Check this out guys: The bumps on top of the tentacle are done with displacement. In fact the same displacement map across the tentacle. How can it be, that the amount of displacement seems to be inverse to the thickness of the geometry? I would expect the displacement to be uniform across the geometry, regardless of the geometry on which it sits? Can anybody make sense of this for me, please?
  4. Noise in glass materials?

    Hello folks, So... rendering glass in Mantra. (For me at least) It seems to be quite a noisy affair. I first used the glass shaders in the material library, but putting together a minimal shader with material builder (a PBR glass node: reflect 0, refract 1, roughness 0.2, IOR 1.05; a PBR reflect node: reflect 1; refract 0, roughness 0.1 and IOR 1.5) reduced the noise a lot. But... I still have a fair bit of noise in my indirect refraction and direct reflect layers. Increasing values in in my Mantra render node of course improves things, but not nearly as much as I'd expect for the hit in render times. Any suggestions as I tinker with this?
  5. As I understand it, stylesheets give you the opportunity to have multiple conditions per override. I have basically organised my stylesheet with a material per override and then I add in the material assignments per geometry with conditions. However, I have geometry that drops out and renders default grey if I have multiple conditions on the same override. Does that sound familiar? Am I doing stylesheets wrong?
  6. Bumping this. I'd love to know this as well. If it is a feature at all...
  7. Do any of you experience with replicating 1 to 1 the look you have in Substance Painter in Houdini 16 using the Principled Shader? The PBR metal/rough workflow with the metallic and roughness maps seems to be straight forward, but plugging in my maps from Substance Painter as is, produces a render that is much darker than what I have in Substance Painter. Perhaps the colour space is off?
  8. Substance Painter to Principled Shader

    So far, it looks like it is a colour space issue.
  9. Mantra render trouble

    Sorry. Nothing to see here. I realise now that these are preview render artefacts. D'oh!
  10. Mantra render trouble

    Look at my render here... Notice I have these funny effects where some render buckets appear to not have finished rendering. I have pasted in my mantra settings to the right top and bottom. What is causing these render anomalies?
  11. Recreating "Overlay" blendmode in /mat nodegraph?

    Thanks eetu. Inspecting it now. No Overlay - but Softlight, which will do nicely. Thank you!
  12. 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?
  13. uniform volume material to create fog

    Works like a charm. Thanks so much bran_daid!
  14. I am adding the uniformvolume material to my geometry to get simple and quick fog. Works like a charm (the green example at the top). Why I get the enable dispmap warning, I do not know - displacement is not enabled. Now, if I plug in some more detailed colour information (bottom sample), the fog disappears completely. What am I doing wrong here? Plugging into the colour input is just one example. It seems this material doesn't like to get any inputs. That can't be right?
  15. image adjustments to textures in /mat

    Thanks for the overview davpe!
  16. Again I am comparing to Maya's Hypershade, where you have all these nodes for adjusting a texture's HSV (Hue Saturation and Value), levels, gamma, curves, brightness and contrast etc. Does Houdini have any equivalents in the /mat context? I see all the nodes in /img, but does that mean I will have to leave /mat and adjust my textures in /img or is there a way to keep things inside the /mat context? ----- Or is the correct/intended workflow that you work with your textures over in /img and then bring them into your shader via op:img/img1/null1"?
  17. How To ?.. Export A Shop Shader...

    But... if you have to do it between computers?
  18. Random values for material inputs

    Thanks symek. I just really want a random number inside a range. That is all. It doesn't need to be tied to a point or anything. All I want is a random number inside a set range to drive my shader. The geo is part of a HDA, so I just want random variation on certain shader parameters every time another instance of the HDA is created. How do I do that then?
  19. I am trying my hand at random values. My expression here fit(rand($PT), 0, 1, 0.7, 1) is meant to input a random number into saturation between 0.7 and 1.0. But as the render shows, it seems to just input 0 into saturation. What am I doing wrong here?
  20. Hello guys, I am trying to build a shader, that in addition to what I have in the image, layers a black and white gradient in along the Y-axis. I am certain it must be very straight forward for anybody with more than a week of Houdini experience. Could anybody please point me in the right direction or outline the steps? Thanks in advance!
  21. From SideFX' tutorials on UV Basics III, I understand that you can connect to an image brought in and edited in the /img context (via the null node, named OUT for example), and then reference it in other contexts, specifically the /mat context, via the syntax of op:/img/img1/OUT On the SideFX forums I got the suggestion of instead using op:/img/tex/OUT This is what I get. Actually, I get that whether I use “op:/img/tex/OUT” or the standard “op:/img/img1/OUT” Oddly, my material turns this light pink as opposed to the standard grey, either way, when I try to call in the texture from null node. I want to be able to edit my texture images with all kinds of colour corrections and procedural tools over in /img and then bring them in live into my shaders in /mat. What am I missing, or messing up?
  22. image adjustments to textures in /mat

    Answering my own question: It seems the color correction node is a good place to start...
  23. Alright. I think I have figured out a solution: Using the layer node allows you to add UV sets to a geometry, that you later than pull in using the shading layer parameter node. This should work not just for UVs but also for colours and alpha channel values.
  24. I have a layered shader, where say the material inputs have a UV scale of x20 for example, and the masks between the different layers have a UV scale of x1. In Maya, you would simply adjust that on the UV node attached to the texture maps. How do I do this in Houdini?