Hello there,
does anyone know how to convert the karma normal aov into a tangent space normal map? It seems to me that the rendered normal aov is in world space - at least not in tangent space - and I need to convert to tangent space. How to do this?

Thanks,
Dag

ananittarhib
By leveraging Houdini’s powerful VOPs and attribute management, you can convert the Karma-rendered normal AOV from world space to tangent space normals. This involves computing tangent and bitangent vectors, transforming the normals using these vectors, and exporting the result for use in further shading or baking processes.

Thanks ChatGPT!


Inside a Karma Material Builder I managed to put down an 'MtlX Tangent' node and pipe that into Base Color which gives the look I think you're after. Getting that out to an AOV or baking it to a texture map is something I haven't looked into.

@Hamilton Meathouse - thanks for your answer. Would have been great if this had worked. But I just tried that and I got something out that is definitely not correct. Basically it looks like various colors in some voronoi pattern across the model. I cannot post images of the the shot/model, but I've attached a simple image to illustrate that I'm not really getting what I would expect.
Any idea as to why it does not work?

@ananittarhib - I know that this is what needs to be done, but I'm looking for a "how to" do it. Do you know how to do this?

Thanks,
Dag