Refraction Render Element problem

[fewlo]

Hi all,

I'm having issues when using 'affect all channels' in my glass materials.

I have comped this test image using LWF and the following elements; bg, gi, lighting, ref, refract, self illum and spec, and all are 'add' layers in photoshop/after fx, in 16bit tiff format.

I can get exactly the same comped image as the beauty pass with the layers when 'affect color only' is used, but obviously my multimatte elements no longer work correctly.

Using 'affect all channels' for the glass results in the problem image...

Please can some of the vray masters have a look at this and help me understand what I'm doing wrong? I'm pretty new to comping but thought I had the set up sorted!

Many thanks, Mike

[fewlo]

Hi all,

Is there anybody out there who has any ideas on this?

Cheers, Mike

[fewlo]

Hi all,

Somebody must know what I'm doing wrong? I know there are workarounds using masks but I was hoping to understand the basics of comping...

Any thoughts would be greatly appreciated.

Cheers, Mike

[gagui]

Hi,
if you are doing the comp in after effects, try to change to use linear mode for blending in project settings.

[fewlo]

thanks for the suggestion, unfortunately that made the comped image look even less like the beauty pass. have you had the same problem in the past?

[3DMK]

What blending mode are you using for the reflection???
It also looks like you're using raw reflection instead of reflection as it is so much brighter

[fewlo]

hi, its actually the refraction layer that causes the issue, but all of the layers are 'add' in after fx, or 'linear dodge (add)' in photoshop. I've also double checked and it is the VrayRefraction element used, none of the raw elements.

I suppose this could be a render theory issue, as I can get rid of the problem if needs be with a workaround, but ideally I'd like to resolve the problem before implementing comping on a live animation...