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Been working on this scene trying to puzzle out why my ocean results were being unpredictable, and i've found some odd behavior.
Setup is a vray plane with a blue material on it, and a flat object sat just above blending from the same blue color to a shoreline.
First thing is that when an opacity map is added the material gets darkened significantly no matter what values are being used in the opacity map itself or how little it affects the materials. This is an object which sits on top of a vray plane. with no transparency it nearly blends perfectly - trying to add a gradient at one end to blend it into the vray plane drastically changes the color of the material.
one odd thing here is that with the opacity map at 100, the vray plane just under the newly transparent area actually gets brighter.
With both diffuse colors exactly the same I still get a huge shift towards darker when an opacity map is added on one. Turning shadow casting off and setting up trace sets so the vray plane cant see the object above it do nothing to the result, it happens when the opacity mapped object is isolated too.
I thought it might be affecting the reflection, so I did some more tests. The other issue is despite being unlinked, the refraction IOR has a pretty significant effect on the amount of reflection - with zero refraction or opacity being used in the material in this example.
For this second issue I made a new vray material from scratch, turned up the reflection, unlinked the ior's and was able to watch the refraction IOR have a significant effect on the amount of reflection in the material editor.
none of these behaviors seem right to me - they're hugely unpredictable and produce different results when viewed through glass and from glancing angles so I cant just visually match them as the second the camera moves, they don't match again.
Setup is a vray plane with a blue material on it, and a flat object sat just above blending from the same blue color to a shoreline.
First thing is that when an opacity map is added the material gets darkened significantly no matter what values are being used in the opacity map itself or how little it affects the materials. This is an object which sits on top of a vray plane. with no transparency it nearly blends perfectly - trying to add a gradient at one end to blend it into the vray plane drastically changes the color of the material.
one odd thing here is that with the opacity map at 100, the vray plane just under the newly transparent area actually gets brighter.
With both diffuse colors exactly the same I still get a huge shift towards darker when an opacity map is added on one. Turning shadow casting off and setting up trace sets so the vray plane cant see the object above it do nothing to the result, it happens when the opacity mapped object is isolated too.
I thought it might be affecting the reflection, so I did some more tests. The other issue is despite being unlinked, the refraction IOR has a pretty significant effect on the amount of reflection - with zero refraction or opacity being used in the material in this example.
For this second issue I made a new vray material from scratch, turned up the reflection, unlinked the ior's and was able to watch the refraction IOR have a significant effect on the amount of reflection in the material editor.
none of these behaviors seem right to me - they're hugely unpredictable and produce different results when viewed through glass and from glancing angles so I cant just visually match them as the second the camera moves, they don't match again.
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