fresnel reflection, with a reflection map

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Old 11 November 2013   #1
fresnel reflection, with a reflection map

Does anyone know how i can make a fresnel reflection while also using a reflection map?
I know the method of using the ramp and samplerinfo connecton to achieve this, but i cant figure out how to do it while also uing a reflection map to mask the variations of intensity.

I read and tried to use the ramp and samplerinfo node together with a multiply divide node. I connect the ramp and reflection map into the multiply divide node, then connect multiply divide into reflection of the main shader.

I dont know if i connected them right, or if this method works at all..

Can someone help me?
Old 11 November 2013   #2
If you use V-ray or Mental Ray materials, you can simply enable Fresnel in the material itself and you'll get the same effect without having to connect anything.

If you want to use ramp, plug the ramp into the "Amount" slot. The "Amount" slot works the same as multiply/divide.

For Vray, every color attribute will have an accompanying "amount".
For example. diffuse color & diffuse amount, reflection color & reflection amount, etc.
I believe it's the same for MR too.
Old 11 November 2013   #3
thanks for that answer, i will try. But im not sure what you mean by the amount slot??
Old 11 November 2013   #4
Did a quick check and the wording is slightly different on each renderer.

Mental Ray
Diffuse Color & Diffuse Weight
Reflection Color & Reflectivity.

Vray uses "Amount"

Redshift uses "Weight"
Old 11 November 2013   #5
thanks, i tried around with this but i couldnt really make it work. Maybe i had some wrong settings, i dont know. However, i connected both the ramp and reflection map to a layered texture and then this to the reflection slot. It seems to work. Just need to find out if its accurate...
Old 11 November 2013   #6
If the ramp is for fresnel, you don't need that. There's a proper physical one built into the shader. (assuming MR here, since you said "reflectivity"): Attach your reflection map to reflectivity (make sure "alpha is luminance" is on in your texture) then under the BRDF rollout, enable "use fresnel reflection".
Old 11 November 2013   #7
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