Odd Reflection Problems

# 1 27-11-2005 , 02:19 PM

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Well I have a question about Mental Rey Dialectic Materials and HDRI. I have rendered this ball /marble thing in Mental ray using the all popular Uffizi HDR image. The ball is a dialectic material. Now, the question is, how come the clearest reflcetions are on the bottom? The plane underneath is a Phong E with reflections around 0.060. And why are there 3 seperate reflections on the top??? Anyone wish to clarify? I'm sure this can't be realistic at all!

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Last edited by MattTheMan; 27-11-2005 at 04:00 PM.

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# 2 27-11-2005 , 04:49 PM

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Re: Odd Reflection Problems

Originally posted by MattTheMan
Well I have a question about Mental Rey Dialectic Materials and HDRI. I have rendered this ball /marble thing in Mental ray using the all popular Uffizi HDR image. The ball is a dialectic material. Now, the question is, how come the clearest reflcetions are on the bottom? The plane underneath is a Phong E with reflections around 0.060. And why are there 3 seperate reflections on the top??? Anyone wish to clarify? I'm sure this can't be realistic at all!

Originally Posted by

Now, the question is, how come the clearest reflcetions are on the bottom?

My guess is that it is because the floor surface is reflective being a phong E shader. The sphere recieves a reflection of the scene from the ibl node and a reflection of the scene from the floor, increasing the intensity of the reflection on the sphere on the bottom half.. the top half only gets a reflection from the ibl node.

unsure on the second question..

You might try a re-render with a lambert shader on the floor and hide the primary visibility for the ibl node. Just to compare..

mayafreak3

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# 3 27-11-2005 , 05:46 PM

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OK man thanks will do!

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# 4 27-11-2005 , 05:55 PM

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Well, this time I rendered this with the IOR setting on 2.0. The thing is that EVEN WITH THAT, which I am pretty sure is the opacity of the shader, still the clearest reflections come out on the bottom. The plane underneath is Lambert 1. THanks for yer help so far Mayafreak, user added image