Houdini gltf import

Hello Stephane
I just wanted to report you that with the update 1.3 the possibility to import Metalness and Roughness as vertex attribute is no longer possible …it’s sad , it was really a plus compared to other scultping app…but as i understand in the log it work on blender , at least it’s good news for blender users !

Bonne continuation !

Ah yes I thought about that but I didn’t know if Houdini could support multiple vertex color.

Roughness/metalness vertex export is mostly a Nomad thing and glTF Importers and others 3d softwares all work differently… it’s annoying :confused:

I could add an option to export it as before though, since I still need to support both method at import.
It’s not top priority though so no promise.

Yes i understand !
It would be nice to have the option to export it in “native” format if you can
now i got something but it’s very much like it was with the colors , some numbers hard to decode…

…And you know it’s pretty much an Houdini thing too to store attribute on vertex/point :wink:

The “hard” to decode colors is probably an Houdini glTF issue, it’s probably low priority for them though.

I don’t know much about Houdini but assuming the colors are easy to decode, is it easy to tell Houdini “roughness is R components of color_1 and metalness is G components”?

What is weird is that Color_1 is a 4 component integer , if i remap the first component it look more like the metallness and i couldn’t extract anything from the 3 others…

It should be similar to the Color_0 decoding https://www.sidefx.com/forum/topic/75110/.

At the moment:
Red = Roughness
Green = Metalness
Blue = Masking
Alpha = Unused

It might change in the future if I add more painting channels.

ok , i will keep on testing and trying the depack suggested on the forum
it’s true that it’s similar value that the one we had on Color_0
as i didn’t succeeded with Color_0 and was taking colors from the .obj…

Thanks !

Hi again !
i get it !
everything is packed as described on houdini forum on the first component of Cd and Color_1
the others component are meaningless…
if someone else trying to import to Houdini…
put this in a wrangle

int packed=int(p@COLOR_1[0]);
int red = packed & 255;
int green = shrz(packed & 65280, 8);
int blue = shrz(packed & 16711680,16);


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Hello Benjamin, I’m also trying to do the same thing importing GLTF in Houdini.

When you mean “a wrangle” you mean an attribute wrangle node, right? I can’t seem to figure out what I’m doing wrong. Cd and COLOR_1 are blank whatever I do in Houdini, despite the same GTLF showing up fine in Blender.

Did you eventually get it to work?

Hello Efflam
i will have to check the forum
here is how i do it now
Feel free to share with whoever need it !

you will have metallic, roughness and mask also as attribute
you have to export as gltf , glb
layer aren’t supported but it’s good to have roughness and metallic to use in shader

Have a nice day


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It worked (including metal/rough)! You made my day.

For anyone reading, I had to make sure the GTLF loader node in my obj network is set to load “mesh” and “promote point attribute to vertex” was turned off for this method to work.

Thanks again,