Blender Settings

[KurtH]

So we've been playing with getting the object to render nicely for producing movies of spins with better lighting quality. There's still some room for improvement but the results have been pleasing thus far. Here's where we're at with settings. If I can get a screen grab of the nodes I'll add that later. I am curious if we can get the GLSL shaders Kintsugi is using to work in Blender... but I have a way to go to level-up my skills to that point.

The Blender renders we had to mess a bit with the textures. We used the Principled BSDF in Blender 4.1

Diffuse -> Base Color (and depending on the object may have had a slight hue/sat adjustment along the way to tweak the color)

ORM -> isolate (Green/roughness channel) -> Roughness

Specular -> Specular IOR level

Normal -> Normal

(we had blender export at TIFF and then used Premiere to turn those TIFFs into video as Blender’s video rendering sometimes can add posterization on the gray background we use).

[Michael Tetzlaff]

Hi Kurt,

Sorry for the delay in responding.  Here's what I expect will give you the best results in Blender:

First of all, I suspect you've already figured that out (or maybe we already had an exchange about this), but for the benefit of others, there's a known issue where Blender does not open GLB files exported by Kintsugi.  I don't know if this an issue with Kintsugi or with Blender -- we use a third-party library for saving the GLB files and I haven't dug into it deeper than that yet.  The workaround is just to import the OBJ or PLY exported from Metashape, which should be the same geometry but without the textures set up.

For the surface shader type, I would recommend using the "Specular BSDF" rather than "Principled BSDF."  This only works with the EEVEE renderer, so it won't work if you need to use Cycles.  But it's going to be the most accurate to Kintsugi's export, comparable to Sketchfab for material accuracy but with Blender's improved lighting capabilities.

In general, you want to hook the textures up as follows:

• diffuse.png -> Base Color
• specular.png -> Specular
• roughness.png -> Roughness
• normal.png -> Normal

However, there are few important adjustments to make besides just hooking those up.

First, make sure each texture has its color space set correctly.  They should be as follows:

• diffuse.png: sRGB
• specular.png: sRGB
• normal.png: Non-Color
• roughness.png: Non-Color

Second, by default, Blender will try to use the alpha channel of roughness.png for the Roughness map.  To fix this, you need to open the "Shader Editor" and connect the "Color" pin from roughness.png to the "Roughness" pin on the Specular BSDF node (by default it will use the Alpha pin instead).

Here's what it should all look like (with the Roughness fix circled):

Regarding GLSL shaders, we'd need to go into the Blender source code or at least write a plugin for Blender in order to support custom shaders -- which could be done in theory but would be a more involved project that isn't probably going to be in the priority backlog right now (unless I come across an honors student interested in taking it up or something like that).

[KurtH]

Thanks. I'll play with EEVEE a bit more.

The method I mentioned above was trying to get the closest approximation in Cycle (which historically produced more realistic looking renderings, albeit slower). But as you point out a recent update to Cycles changed the specularity options.

[Michael Tetzlaff]

Sounds good -- I'll also add looking into support for Cycles to the backlog.  It looks like it might be possible using an Open Shading Language script.