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View Full Version : Samplerinfo node and BRDF in mia.


whdlsrl23
03-19-2012, 03:50 AM
Hi guys...

Now I'm studying about shading..

Recently I've downloaded a few shading from creativecrash site.

And I watched a lots of shader is used by Samplerinfo node....So I looked it up a lots of site.

But I recognized Samplerinfo node is same with BRDF in mia_matrial_x....

is it right? or did I miss understand?

If samplerinfo and BRDF are same, why many people use Samplerinfo node.....

studying shading is really hard, plz help me...

Thank you

InfernalDarkness
03-30-2012, 11:52 PM
Samplerinfo is not the same as BRDF. Samplerinfo literally "samples" the info you need, often used for Normals and outputting this data to another node. BRDF has to do with the reflections at various angles, and generally should just be set to Fresnel. Almost all materials actually use Fresnel falloff.

whdlsrl23
03-31-2012, 01:00 AM
Thank you very much....but I can't understand exactly..

CG makes me sad...

InfernalDarkness
04-03-2012, 01:46 AM
Maybe this will help:

The BRDF section of the mia_material_x controls how the Normals affect reflections. These values can take incoming nodes, but do not output any data directly.

The samplerInfo node analyzes the Normals and can link this data (export it, basically) to another shader or node, including the mia_mat_x if you wanted to.

Thus, you could for example link the samplerInfo to a mia_mat_x's Diffuse color, but you could not link the BRDF values in the same way. You could link the samplerInfo to a shader's bump map for example; you could not directly link the BRDF data to the bump map of another shader.

Consider the samplerInfo a "Utility" node which can affect all kinds of things, and the BRDF attributes are just that: attributes of a shader.

whdlsrl23
04-03-2012, 03:10 AM
Wahoo
English is not first laguage, so I can say only Thank you very much.

Maybe this will help:

The BRDF section of the mia_material_x controls how the Normals affect reflections. These values can take incoming nodes, but do not output any data directly.

The samplerInfo node analyzes the Normals and can link this data (export it, basically) to another shader or node, including the mia_mat_x if you wanted to.

Thus, you could for example link the samplerInfo to a mia_mat_x's Diffuse color, but you could not link the BRDF values in the same way. You could link the samplerInfo to a shader's bump map for example; you could not directly link the BRDF data to the bump map of another shader.

Consider the samplerInfo a "Utility" node which can affect all kinds of things, and the BRDF attributes are just that: attributes of a shader.

InfernalDarkness
04-03-2012, 03:15 AM
Nor mine either! I hope I didn't over-explain it or add any confusion.

whdlsrl23
04-03-2012, 03:33 AM
It's really helpful for me.....really thank you.

Nor mine either! I hope I didn't over-explain it or add any confusion.

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