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Nicholas Ralabate

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Everything posted by Nicholas Ralabate

  1. Anybody using RTX 2080Ti with CentOS?

    I'm trying to get a RTX 2080Ti up and running on Centos7, but after installation X doesn't start and when I switch to console to log in I see a "garbled" screen. I am running latest 450.80.02 driver, and I also tried updating from CentOS 7.7 to 7.8 but it still doesn't work. In my dmesg I see a few lines about "RmInitAdapter Failed" which I'm pretty sure means bad driver. I think my next approach will be slowly roll back driver versions, but I wanted to check here since RTX + CentOS seems like a pretty standard combination.
  2. Wrangle-based Sourcing in Sparse Smoke Solver?

    Hi, I am trying to use Gas Field Wrangle DOP to do my sourcing in a sparse smoke setup. I am testing with the most basic setup possible, but this doesn't work: f@density += volumesample(0, 0, v@P); This wrangle works in dense smoke setup, so I assume I am missing a line or two that takes into account the new active or stencil fields. Does anybody have an example of this working?
  3. How to see render time in RfH?

    At the RenderMan Art & Science Fair last week they announced that IPR stats are coming in RenderMan 24 so I will just wait until then. https://app.livestorm.co/pixar-animation-studios/r24-for-tds?utm_source=Livestorm+company+page
  4. How to see render time in RfH?

    I'm just now starting to use RenderMan 23 in Houdini (have previously only used it in Katana) and I have a simple question -- how do I see the elapsed render time? I am sticking to the /out context for now so I am using the Render View tab. From using Mantra, I am accustomed to seeing both the elapsed render time, and then when the render finishes the total render time in the top right in the HH:MM:SS format. Is this possible out-of-the-box with RfH 23? So far, the only way I can see total render time is to start a background render and then view the result in it, which adds a tremendous amount of overhead.
  5. In Mantra, you have to make your own simple shader using the Occlusion VOP and assign it to everything... in RenderMan you need to switch integrators to PxrOcclusion. https://www.sidefx.com/docs/houdini/nodes/vop/occlusion.html https://rmanwiki.pixar.com/display/REN/PxrOcclusion
  6. I'm doing some simple animation of visibility but I'm running into some akward situations which means I am probably doing it wrong. Originally I was animating visibility at the object level... but I am also object merging everything into one final object node for just-before-rendertime cleanup (Fuse SOP, Clean SOP). It seems like there isn't an option on Object Merge SOP to only merge in visible objects. The other odd thing is that I like to animate with the data tree set to "Object Visibility" so I can quickly solo the objects I am animating. However, this seems to conflict with the object-level visibility flag such that it won't let me force visible something that is keyframed to be not visible that frame. What I am resorting to now is setting object visibility at the SOP level with Switch SOPs and NULL SOPs but it feels wrong because I have to dive in and out of networks to understand what's happening instead of just glancing at curves in the animation editor. I'm sure this is a simple thing, and I'm just not thinking about it right. Any advice would be appreciated! Specifically, what is the best way to animate visibility but also be able to Object Merge things and generally have a tidy workflow.
  7. How to apply displacement in shaders

    You just bind in your Cd attribute and then use that to drive the displacement amount. I included a minimal example, but the principle is the same when using premade shaders like Classic/Principled. If you do it yourself don't forget to turn on the vm_displacebound setting on the object. nr_simple_displacement.hiplc
  8. How do Mantra lights know which light shader to use?

    Thank you, thats's great info!
  9. I can dive into the light and see the hlight OP, and I see the relevant SOPs but I don't see where the light shader is wired up. I can also expose the hidden render parameter for light shader but that just gives me a blank field. How does a light know which light shader to use? Also, are there any differences between light shaders between H8/H9 approaches? I am mostly concerned with PBR backend. I see in $HH/Vex/Light there are some light shaders assigning to the Cl variable but I'm not sure if that is specific to raytracing backend or if it applies to both raytracing backend and PBR backend.
  10. Magic Spell

    cool! whats that crazy refractive effect you did in comp when the first spell hits the troll?
  11. Volume Displacement Houdini using Mantra and/or Arnold

    for texture projection over volume, you can just use the toNDC VOP in mantra... it will convert every position to a value in the [0..1] range which you would then plug into a texture VOP
  12. Houdini Mac user population

    I used a 2012 MBA (4C@2Ghz/8GB RAM) to learn Houdini for the past few years (mostly SOPs and POPs)... it was ok. I had a couple of problems with the OpenGL viewport crashing when H16 first came out, but that was eventually fixed. P.S. I since moved on to a simple Linux box (8C@3GHz/64GB RAM), a basic build with a ryzen and a potato gpu ended up being cheaper than another MBA/mini (I can't afford the fancier stuff).
  13. In Mantra, most of the single-lobe VOPs (PBR Diffuse, PBR Non-metallic Reflection, PBR Metallic Reflection, PBR Emission) have layer inputs/outputs so that they can be chained together with energy conservation. However, PBR Diffuse and PBR Metallic Reflection only have layer OUTPUTS. Why is this? What if I want to put together a shader where those nodes don't come first yet they are still balanced energy-conservation-wise? I feel like I am missing something simple in terms of layering here.
  14. Any way to layer with PBR Metallic Reflection or PBR Diffuse on top?

    Thanks~! I didn't realize that did energy conservation, I thought it just lerped the bsdf!
  15. Question about hair shader source

    Hi all, I am trying to level up my Mantra knowledge by digging into the source code for some of the shading VOPs I use all the time. I am a bit stuck though on two things: 1. When I right click and choose "Type Properties" on pbrhair_tt I see that it calls the VEX function hair(), but when I look at the source code for that function (in $HH/vex/Surface) it in turn is calling wireblinn() and wirediffuse(). I cannot find the definition for those two files anywhere. Where should I be looking? 2. I see that there is a hair_eval.vfl and a hair_sample.vfl in $HH/vex/CVex... these seem to define the bsdf, but I don't understand the connection of the hair() function mentioned above and this bsdf function. How do they call each other? Or is Mantra in charge of calling them both separately, in which case how does the shading VOP know to associate these two things? I really appreciate any leads, this isn't a production thing I'm just super curious and spelunking around trying to make connections.
  16. GLTF animation import

    Send an email to support and have your name added to RFE #96785 !~ That way we can have this built-in in the future!
  17. Could it be that your diffuse limit on the Mantra ROP is too low? I'm not sure why that would come into play on a transparent material though...
  18. GLTF animation import

    I don't think Houdini supports GLTF 2.0 (which I think is the version of the standard that added skeletal animation). Anyways, I can't find anything in the docs about it... https://www.sidefx.com/docs/houdini/nodes/obj/gltf_hierarchy.html Blender supports GLTF 2.0, maybe you can use it to convert to alembic then bring it back into Houdini? https://docs.blender.org/manual/en/2.80/addons/io_scene_gltf2.html https://www.sidefx.com/forum/topic/72189/?page=1#post-305584
  19. UV Flatten is all you need to do traditional manual UVs, it lets you draw seams and unwrap and pack:
  20. dof, circle of confusion

    super-necro, but to get the camera visualizations that were asked about you select the camera, hit enter in the viewport and hit "z" "o" and "f" to toggle through the focus and clipping visualizations... this isn't listed in the docs for some reason (just submitted an RFE)
  21. Ce Trivia

    Ah, that's right I forgot about that checkbox on Mantra ROP... otherwise those exports aren't exported... thanks! I assume you meant transmission and nested dialectric though, I thought dispersion didn't need any additional exports... (P.S. In the above network the Compute Lighting VOP is actually still exporting even when the Switch VOP isn't grabbing its input... so probably not the best test... to use JUST the Unpack Layer VOP, you would also have to pipe Ce into a Bind Export VOP) (P.P.S. You do in fact need to add a Layer Export VOP yourself if you want to use transmission... there were a few of these inside Compute Lighting VOP dealing with transmission and nested dialectrics. There was also one for dispersion, but this way seems to work without it...?)
  22. Ce Trivia

    What is the difference between exporting Ce in a Bind Export VOP, feeding a Constant VOP into the Ce input of Compute Lighting VOP and feeding the output of PBR Emission VOP into either the Ce or the layer input of the Compute Lighting VOP? It seems like even if I don't feed the Ce from a Bind Export VOP it into Compute Lighting it gets... combined/computed somehow (additively?). The only other difference I notice is that I am only able to turn off emissive as light source when I use the PBR Emission VOP. Is it possible to do the same if I am just using Bind Export VOP? I am using PBR engine by the way... super curious about what is going on under the hood.
  23. Ce Trivia

    Oh sweet, getraylevel() is new to me... thanks for the reply! I also found a few more details about how Ce is used on this page, but it made me wonder... since Compute Lighting VOP doesn't compute lighting in PBR mode, can it be essentially replaced with a layer unpack? https://www.sidefx.com/docs/houdini/nodes/vop/computelighting.html (Again, this is just for understanding purposes, not a production problem)
  24. Mantra & threadripper - Progressive vs bucket

    Are you talking about the Render View or batch renders? In general I always turn off progressive rendering in Render View both because it seems slower and it also overrides some of your Mantra ROP settings (I believe it forces Raytrace mode, and a particular filtering mode for volumes but I am not 100% sure).
  25. Materials, shaders within Houdini

    Here is a good playlist for beginners: