Karma XPU and MaterialX - lesson 1 - Shader building basics

[@MDUmairKh]

Thanks, brother, this was very useful. I had no basic idea of using materials in Karma. All videos are advanced and assume that you already know about the new renderer. This was much needed.

[@bryanray3915]

I noticed you had some frustration hunting for the nodes you wanted. If you build your material inside a USD MaterialX Subnet, the tab menu will filter out operators that don't work in a MtlX context. The shorter list is *much* easier to parse quickly!

[@rohandalvi]

Thanks. That’s a great idea. I’ll do that in the next lesson.

[@uulatoikka2350]

Wow, yes!!! I have been waiting for this kind of thing while having trouble building MaterialX :)

[@UmairAliMughal2009]

love you bro !, your videos are big part of my learning journey.. #LovefromPakistan

[@ModelWhatYouSee]

I'm not sure if this is shown later on, but how would you apply materials using assignments instead of just drag and dropping. Like this object just has one material, but what about if you have a object with more than one. Say a picture frame that has frame and glass, how do you assign those? Thanks for any help!

[@suri4Musiq]

Can you convert this into a playlist and share it? You always make amazing videos, much love

[@NathanApffel]

Thanks Rohan this is great.

[@JacKsCave]

Thanks a lot!! Its solaris timeeee!!!

[@pinkmoon5332]

wait, NO extra roughness parameters? Says in 19.5 that all the transmission (extra) roughness is "not implemented". Okay then, when? This is imperative for depth blurring into translucent objects. I thought MaterialX supports this, pretty sure it does....but it doesn't seem like Karma is. Is this working in H20? Because it's not in 19.5 from what I can tell. Trying to make the transition from Redshift to Karma (where extra roughness is implemented - over a year ago now.)

[@rohandalvi]

I haven’t tried it in h20. Karma xpu does support absorption and dispersion . I haven’t tried the extra roughness as yet. I’ll try it tomorrow and let you know.

[@pinkmoon5332]

@@rohandalvi grateful, thanks

[@SereneBobcat]

sooooo awesome!

[@paoloricaldone6273]

Thanks Rohan

[@sebastianschollhammer7993]

Hey Rohan, this might be a houdini version difference but in my houdini 19.0.657 the mtlx USD uv texture nodes don't let me set the texture to linear space, which results wrong results for roughness and especially normals.. For me only the standard node works here (USD UV texture). Maybe the problem is not apparent with your model but I just thought I'd let you know :) ps Great video as usual :)

[@rohandalvi]

I will check it out. Thanks for the info.

[@joelchamp1949]

SSS seems to be working in 19.5 which is cool

[@rohandalvi]

Yeah. 19.5 had added a bunch of features to XPU. Instance attributes are also supported.

[@Gyanevlogs]

Hello sir how to use noise in material x

[@HoudinifxAlfredosanmartin]

Thank you so much : )

[@jbiruli]

How to do lookdev with ao and curvature/cavity shading...so that is is transferable to other mtlx supported renderers through USD packaging... say clarisse?

[@rohandalvi]

There is no curvature or cavity shader in materialX in Houdini. You have two options. Either use the curvature sop and create an attribute on the geometry. But you’ll need a high res geometry. Or uv Map the object and bake a curvature map using Houdini baking tools or substance painter. Material X is very rudimentary when it comes to procedural shading.

[@wewantmoreparty]

Yeeeeees🤟🚀❤

[@HoudinifxAlfredosanmartin]

I'm not very sure, but I think a object merge is necessary to precede each MaterialX group

[@rohandalvi]

I’m not sure I understand what you mean.

[@HoudinifxAlfredosanmartin]

@@rohandalvi Hi Rohan and thanks : ) what I mean is that I work with GROUPs, and mtlx doesn't read them individually on "scene import all" in Solaris. I tried all this with my group with a object merge previously in another "geometry", and I made the group there, and thanks to object merge, and since there is another geo (example) it worked for me there (GROUP) read two objects so! but there must be other better example without a doubt.

[@heweiping123]

heighttonormal is not support by xpu yet

[@rohandalvi]

Oh ok. That’s why it’s not working.

[@user-vc1ln3of2w]

Hi! Cool lesson, thanks! I have Houdini version 19.5 and don't have a node mtlxUsdUVTexture. What has changed for this version of Houdini and how can I find this node? Has the name of the node changed?

[@marcosparmentier]

same, I'm wondering if you found it or another node? I haven't yet

[@vertexbend]

​@@marcosparmentierI think I found another node then - with title image.I need to take a look, I haven’t worked with materials for a long time.

[@marcosparmentier]

@@vertexbend i found another too, it works with usduvtexture. in houdini there is always a way 😁

[@carlosrivadulla8903]

delay this tutorial 1month pls, H19.5 is about to release and is going to introduce significant improvements on this

[@yijuyeong1219]

Really??

[@rohandalvi]

I will record the new stuff when 19.5 gets released. I have nothing else to record at the moment and this series is completely planned out. 😅

[@ashrafuzzamankhalid3465]

A request to make a vellum tutorial about Spiderman WEB simulations please...

[@raimuhammaduzairfareed7628]

Check" cg Shortcut" KZbin channel He has this sim

[@ahahlex]

you may check Junichiro Horikawa youtube channel, "[Houdini Tutorial] 0031 Spider Web"

[@ashrafuzzamankhalid3465]

Thank you both of you guys for helping me... Are there any particular video where I can learn Webs are shooting from a certain point to another certain point with simulations and stuff... (Like spiderman shooting a web to a particular object) Houdini's original channel has one but that is really hard to follow up for a beginner like me... Thank you again ❤️😊

[@MrMariozzz78]

u don't use Glsl language isn't it?

[@rohandalvi]

No, I am not very good at coding. I know basics of OSL. I have never used Glsl.

[@avinashlobo]

I love almost all your content, but here I honestly think that some prior basic research would serve the community better. SideFX clearly documents what is and what isn't supported in Karma and MaterialX, so there's no need for guesswork, or trial and error in an instructional video. Height/displacement maps also work fine in both Karma CPU and XPU.

[@rohandalvi]

Point taken. I will make sure I read up on the documentation before I make the next video .