Specularity/Hardness reference for Blender

[kououken]

I made this test image to get a feel for the range of specularity and hardness selectable from blender. Makes it easier to pick settings for say, dry silk, or slimy frogskin, etc. You can also see how specularity settings above 1.0 don't make the reflection any sharper, but the consecutive reflections get out of control quickly.

Hope this helps someone. I'm just not patient enough to do the materials in the xml by hand! Are there any other renders to reference? Like changing IOR, or transparency for example?

[tungee]

tampopo , hanna bi ,ran ...
that looks great, but what means hardness? what parameter is meant?

[lego]

hardness = exponent

[skypa]

Great reference, thank you for that. Getting the spec and hardness right has always been a little try&error-ish.

[OnoSendai]

And what is specularity in the blender exporter?
I have a funny feeling it's fresnel_fraction, in which case, it shouldn't go above 1

[lego]

And what is specularity in the blender exporter?
I have a funny feeling it's fresnel_fraction, in which case, it shouldn't go above 1

mmm that's strange!
I always thought that indigo specularity was taken from blender specular color!
but I did a test and I saw that it takes in consideration the specularity slider too...
so if I set spec color to 0.8 0.8 0.8 and specularity to 0.5, I get an indigo specularity of 0.203 0.203 0.203.
If I set spec color 0.8 0.8 0.8 and specularity to 2, I get an indigo specularity of 4.x 4.x 4.x
maybe an exporter bug? I'm using the last version

[kououken]

Well shoot.. here I thought I had finally figured out how things worked.

What would the settings in blender be, for example, for a perfect mirror?

[OnoSendai]

Well shoot.. here I thought I had finally figured out how things worked.

What would the settings in blender be, for example, for a perfect mirror?

<specular>1 1 1</specular>
<diffuse>0 0 0</diffuse>

[lego]

in the exporter the specularity is set as this

colGamma(mat.specB*specfac)*SpecularGain.val

for each color

I think specfac is the specular slider
I don't know what speculargain.val is...

I'll try to use just

colGamma(mat.specB)

[zuegs]

SpecularGain.val is not used currently and is constantly set to 1.0

so specularity is defined as following:

Red = colGamma(mat.specR*specfac)
Green = colGamma(mat.specG*specfac)
Blue = colGamma(mat.specB*specfac)

[OnoSendai]

Well... whoevers on blender duty.. they need to clamp each component of the specular colour to the range [0, 1].

[lego]

SpecularGain.val is not used currently and is constantly set to 1.0

so specularity is defined as following:

Red = colGamma(mat.specR*specfac)
Green = colGamma(mat.specG*specfac)
Blue = colGamma(mat.specB*specfac)

Are you sure?
I modified the script leaving

colGamma(mat.specR)*SpecularGain.val
I set a spec color of 0.4xx and hit export
in the xml I had a specularity that was roughly 0.25 times the one set in blender!
And I don't get the need to use the specfac value in that expression! it would be much more intuitive to have spec col slider --> indigo specularity

[DaveC]

How very odd!! Last night I posted a final render inspired by exactly the same idea as this image. You can see it at this link: http://www.indigorenderer.com/joomla/in ... temId=3406
I would have done one the same as this one, but I didn't have the patience! lol

[zuegs]

@lego:
as long you have the "colGamma()" function in the formula you do a inverse gamma correction dependent of the col-exp slider in the exporter... you can set col-exp slider to 1.0 or remove "colGamma()" to match values between Blender and Indigo.

@OnoSendai:
you are right, will try to remember this for next release exporter is still very experimental