Welcome to od|forum

Register now to gain access to all of our features. Once registered and logged in, you will be able to contribute to this site by submitting your own content or replying to existing content. You'll be able to customize your profile, receive reputation points as a reward for submitting content, while also communicating with other members via your own private inbox, plus much more! This message will be removed once you have signed in.


  • Content count

  • Joined

  • Last visited

  • Days Won


Community Reputation

24 Excellent

1 Follower

About Matt_K

  • Rank
  • Birthday 11/10/1970

Contact Methods

  • Website URL http://

Personal Information

  • Name Matthew
  • Location Cape Town
  • Interests Art, music, animation, guitar, painting, drawing, surfing and reading - in no particular order!

Recent Profile Visitors

7,207 profile views
  1. Well, if you put down a standard box, that should represent 1m x 1m that you could use as scale reference. Looking at your screenshot, I'd say that's a pretty big hat, around a meter squared - if those units on your grid are at meter scale. Incorrect scale can cause problems for DOPs / Cloth / volumes and also rendering, so It's not a bad idea to have a human model that is scaled correctly in Houdini units, that you can reference. Hope that helps! Matt.
  2. Check your geometry scale - it will seriously affect how the density is calculated. Matt.
  3. Is it perhaps the collision object padding? If I remember correctly, by default there is a small padding amount added, and perhaps it is this pushing the objects away from each other? Matt.
  4. Hey again, Your settings seem ok, though I tend to keep my diffuse limit to 1, really helps to reduce noise. Often the second diffuse bounce doesn't really add a lot more to the image. Check your displacement bound - try and get it as low as possible before artefacts appear, as that may speed things up as well. And try and keep your lighting rig simple - I usually have a sun light and an hdri, and that seems to work well in most cases. As a last resort, try rendering without the fluid interior - can really speed things up, but it will look quite different. Without knowing what else is happening in your scene, I'm afraid that's about all I can suggest! Matt.
  5. Hey Robbert, It's probably because a few frames haven't meshed properly. Have you cached the 'particlefluidsurface' output to disk? If so, you can then step through and find any broken frames and try tweak the settings to get it to mesh correctly, and re-cache just those frames. Otherwise, perhaps the spectra mask files aren't being correctly generated - check the filesizes if you cache them out and see if there are any 0kb ones. Lastly, on the geometry node that your ocean is in, try setting the dicing mode to 'full predicing' - ( yourGeo > Parameters > Render > Dicing ). This will use a more memory at render time but has fixed issues for me with rendering oceans, and can actually speed up rendering. Hope that helps! Matt.
  6. Nice! Lots of fun to watch. Matt.
  7. Hey, If the object has "Render polygons as subdivision (mantra)" selected, your generation time will be very long. I have found that specifically with the flattank setup, leaving that unchecked significantly speeds up the generation of displaced geo and looks pretty much identical. Hope this helps, Matt.
  8. Hello all, Has anyone else run into this issue? Using Houdini 16.0.597 on Linux, I created a flip sim, used the Ocean Flat tank setup and created an extended ocean and all works well. But at render time, the flip part of the sim that sits above the waterline appears to be missing something and renders very dark. I have checked the reflect/refract limits, checked the displace bounds and I'm using the standard oceansurface shader. I have generated a suitable interior volume, and the issue is there with or without the interior. I have a screenshot of the issue (taken with my phone cam so apologies for the quality) - just the ocean surface, no interior. I have tried with simpler sims, different settings on the shader, and the problem persists... Any advice would be appreciated! Thanks, Matt.
  9. Hey ikoon, Works as expected for me - selecting a new key deselects the previous one. Using H16.0.597 Happened to me once - had a faulty shift key on my keyboard... Matt.
  10. Hi, Are you perhaps object merging it into another geometry object in your custom deformer? Are you doing any transformation/scaling in the subnet? If so, you will need to compensate by either inverting the transform or simply scaling it back down before VDB-ing. Or, does the parent object have any scaling at the object level? This can cause issues down the line, and if you do, try moving the transforms/scaling to SOP level, cleaning the object transforms, and see if that makes a difference. Hope this helps! Matt.
  11. Hi Naoki, Will try and get an example for you a little later on today. Matt.
  12. @Jason - try this, can't quite remember where I got it from, but it works for me in H16. Matt. Slate_houdiniTheme.zip
  13. Hi David, There may be two things causing an issue: 1) You have an rgba texture (4 floats) plugged into a port expecting a color (3 floats / vector). Is there an option on the texture node to select either rgb or rgba? Though I think you should still get something working like this. 2) It might be that your filename has the ${F} variable in it - meaning it will be looking for a file per frame. Perhaps try unchecking the option to show files as sequences in the file browser when you select the image? I'm not familiar with Arnold so can't really assist there, but hope this helps! Matt.
  14. Hi Jim, Just a quick note - is it possibly something to do with shadowing that's causing the shimmer? I ran into something similar a while back and it was either fixed by tweaking the "Raytracing Bias" setting on the Mantra ROP > Rendering > Shading tab (I think I had to set it to something like 0.1 for that particular scene scale), or by excluding the inner liquid from the environment light shadow. Was a while back and can't quite remember which one it was! Now that I think about it, it might also have been fixed by upping the light's "Sampling Quality" to 4 as well... Hope you are able to sort it out, Matt.
  15. Hey Soumitra, If you use something like : { parm1 == 1 parm2 == 5} then it behaves as if it was using an 'and' operator. Matt.