"use interpolation" in 1 material causes noise in entire image alpha channel?

[Lupaz]

Hi,

Is this a bug?

I was getting noise in the alpha channel of my pass of trees.
I figured it was due to a "prepass"
I finally found 1 object with "use interpolation" checked in reflection (not an object within the tree pass)
By un-checking use interpolation I don't get the prepass that messes up the alpha channel of the trees.

Please see image below
Thanks.

[vlado]

This is very strange. Can you get me a scene?

Best regards,
Vlado

[Lupaz]

Hi Vlado,

I will as soon as I can.
Cheers.

[Lupaz]

for vlado.zip

Above there's a very simple scene with the problem replicated.
Please note that it's on "render mask: selected"

On the rendered alpha, there's noise.
When you un-check Interpolation (on the material of the little box on the right), you don't have the problem anymore.

However, with interpolation on AND "render mask: none", it doesn't seem to happen.

Thanks.

[Lupaz]

I just found that that "render mask: selected" doesn't seem to work well with opacity.

on another scene I can't get the alpha from the tree leafs if I use "render mask: selected".
But if I isolate the trees and render without using "render mask" I get the alpha correctly.

[Lupaz]

the trees are vrayproxies by the way.

[svetlozar.draganov]

I cannot reproduce it.

Could you please let us know what is the exact Vray/3DSMax version you are using, and what steps should we follow in order to get the issue?

Thank you very much in advance.

[Lupaz]

Here's a scene:

http://forums.chaosgroup.com/attachm...8&d=1398872231

[tashko.zashev]

Hi,

Thank you for attaching the scene.
I assume that you want to get the alpha channel only for the current object selected? The render selected feature defines only the rendered area, not the object itself.



It is expected render result for this setup, but if I've missed something please let me know and will check again.

[Lupaz]

Hi Tashko,

Is that the render you get without changing any materials in the scene?

I get something different:

With the scene as is, with the plane selected, I get this rendering:




If I uncheck the "interpolation" option (reflection) for the material applied to the box, with the plane selected, I get this rendering:



Thanks,

[tashko.zashev]

Hi,

Thanks for the examples.
Most probably you are using our older V-Ray 3.00.03 releases, please update to the latest one available on our web site. Currently is V-Ray 3.00.05.
I'm using this build for testing.