originally i made this character the other day for "Run" -- but didnt get the chance to finish an animation. So I decided to re-use him for "Shadow" where I decided to play around with some custom viewport rendering. I did ultimately render with karma, but it was so basic that I might as well have just viewported it-- i just thought it would be a good idea to crank out a proper exr sequence.

And then i did some fun post stuff with good 'ol COPS

Lots of fun, the point renderer stuff was partly inspired by this amazing 2 year old sidefx talk from mark fancher https://youtu.be/qSkG0ac5RmU?t=2289 [youtu.be]

and did the sound myself in ableton for fun !

Finally hopping into this 20 days late

Made this little seamless loop starring my new character Bulby!

Sculpted this character in medium, everything else done in Houdini. Had some fun with kinefx rigging, custom collision deformers, the spark trails, and rendered of course with Karma XPU!

Hello, is it possible to keyframe the lens shader, and if so how? Seems like it should be. I want to animate the "amount of curvature" if possible.

I can see theres a primvar in the camera prim in solaris which is blue (so not animated) for the "karma:camera:lensshader"

usually I just make a matnet and put the lens shader in there. Was thinking way at least when i make changes it doesnt re-trigger my whole lop node graph. I guess I could put it into a matnet in the graph and set it to allow shader parameter animation, and then i do see the values in usd in the physicallens1 shader, with green values for the curvature, but im not sure this matters at all.

Anyway was just digging around trying to figure this out, if there is an answer would love to know. And if there isn't would love this to be added as a feature!

haven't heard of geometry subsets and not sure how that works? i can look into it but any pointers you can give are appreciated. still seems like this should be doable though with the addition of trace sets !

jsmack
They need to be a single mesh to shade continuously.

right, so basically the answer is no for now hope this gets fixed soon!

I can't seem to figure out how to get rid of these lines. They show up in karma / solaris when i have different name attributes for diff parts of the mesh (which it should because it uses different materials for different parts). But even when the mat is the same, and they have different name attributes, i still get these dark lines. if i just remove the name attribute and give the whole thing one name attribute the lines go away. so theres got to be some kind of way to tell karma that these objects are meant to be shaded together as one piece of geo and not treat them as different pieces of geo just because they have different name attributes.

i think i remember hearing that this was not ready in karma xpu yet and needed to be added (hopefully it will be ready soon) but i was playing around with the principled shader and couldnt figure out how to do it in there either which i assumed was how you would do it with karma cpu.

so whats the deal with this, how should i / can i even address the issue now in karma?

thanks

jsmack
is it precision, or ray bias that's the issue? The default ray bias is 1mm, which would miss the other side of thin refractive surfaces like that.

err wasnt aware of ray bias, that fixes it. thanks!

So i have had a few issues with my characters scale, however I believe they are scaled pretty well for houdini. I could and maybe should scale them up a bit, but they are human biped characters exactly the same size as tommy (test geo). I have this issue where the charactrs come from daz and they have a "eye moisture" thin layer above the eye, but they are in such a similar spot that I end up having issues where karma will only show one or the other. I also had artifacts in a previous project where I was using redshift, where I would just nudge them both a bit using a peak sop, but it seems harder to get it to work with karma.

I guess my question is, should I scale up everything ? Is this the best fix? Even though it seems like things are the right scale in sops? Or should i scale my whole scene up just in karma? or am i being silly and should I not have an "eye moisture" layer on top of the eyeball and instead just use a coat or something over the eye in its own shader? or is there some other kind of fix I could try?

brians
I've fixed this now, and will push a fix out in the next day or so.
I'll let you know the release number once that is done

woah! sweet! Thank you Brian!

jsmack
lol dead pixels, are they NaNs?

they could be, im really not sure what the best way is to figure that out.

if i dolly in, it looks like this. if i rotate the camera slightly it goes away completely.

I've noticed that in some of my renders ive been getting occasionally dead pixels, almost like reverse fireflies with xpu (and it seems to only be xpu). a friend mentioned they were having this issue recently and now i'm seeing it as well. Seems like a bug!

im also trying to use the hair procedural, and seem to be feeding it everything it wants, but it is not showing anything in render!

my understanding is that if you say things are in the same trace set together they get path traced as one object or something? anyway, the only time im really familiar with using it is with SSS objects that intersect. you want to make them part of the same trace set if you dont want to get an ugly dark area where the two objects intersect. i was told at some point that this isnt yet supported in karma xpu, but i have no idea! was also just an example.


thanks this list is handy brian!

i think what you want to use is this? https://www.sidefx.com/docs/houdini/nodes/lop/backgroundplate.html [www.sidefx.com]

i have a lot of questions generally about what is supported by karma CPU, vs xpu, and theres an old chart of mantra vs karma vs xpu from the houdini 19 release i think, which is way outdated. it would be nice if this got updated, and / or if there was a good place to see all the differences clearly?

for example, im curious to know if trace sets are supported yet in karma CPU or xpu, i have no idea where I could check that though. i suppose i could use the changelog but that definitely isnt quite as clear.

the viewport here is GL, but this project is in RS. it's happening regardless. I can't easily share unfortunately, the project is kind of a mess, id be happy to show over zoom or give remote access to one of my machines. in the meantime the solution for me sems to be like just re-exporting everything in 19.5 as i need to. very confused here. i could provide a usd but it would be missing a bunch of texture files.

im noticing that if i go into the original asset file for the enviornment, and go to the original stuff that the first usd file was exported from, everything is there correctly and textures show up.

any .usd files that were exported with RELATIVE PATHS enabled from Houdini 19.0 do not show textures in 19.5.

HOWEVER, if i export them from 19.5 instead with relative paths OR without relative paths, it reads fine in 19.5.

So i guess the question is, is there some way to just correct these without having to dive into all my old files and update everything re-exported from 19.5?

so currently im having an issue rendering USD files with TOPs in 19.0, random frames are giving me exit codes and i can't diagnose why they aren't rendering.

i ended up trying to render the same usd files in 19.5 and it's nearly flawless. so i'm hoping to switch over to that.

however there's one major issue i'm having which is that a bunch of textures are disappearing when i open the usd files in 19.5.

so here's an example of one of my usd files in 19.0



you can see it says "@../ASSETS/Home Master 2022.fbm/FG Eight Figurine_EightFigurine_albedo.jpg@" and it shows up correctly in the viewport.

here's 19.5:



you can see it says that and then it makes a little -> arrow that points to the full absolute path (which i checked and is 100% correct).

so i have no idea what is going wrong here or what i'm missing! any help would be greatly appreciated.

wow! thank you! great to know.

jsmack

ChristopherRutledge
meant to attach this image but here's a hip file simplified, you can clearly see the faceting artifacts on the characters hands. if you play with the displacement/normals/SSS radius youc can see it more or less clearly all over the model.

Looks like subdivision wasn't enabled.

ah, that would explain it, where am i missing the subdivision setting? ive been looking for it in karma. i thought that it was "dicing" and it worked differently from subdiv in other renderers like redshift or arnold?