Maya RT / GPU questions - samplerinfo, imageplanes and override background

Hello,

Sorry for the collection of questions, all GPU limitation questions.

1) I’m using a Maya sampler info piping into remap colour node to extract the facing ratio. My shader seems to work fine in the IPR view, however when batch rendering with the GPU I get a different result. In the documentation it says sampler info works with GPU but with some limitations .. what are those limitations ?

2) I’m having some strange behaviours with Imageplanes. I couldn’t get them to show up in a number of shots. However I have one shot where my image plane does appear in the render and I can’t get rid of it without deleting the shapenode from the scene. Are imageplanes generally compatible with GPU rendering ?

3) Is there a way to have the Vray background override respect the resolution or film gate in the viewport ?. Otherwise I can’t use them with the IPR renderer without resizing the window to the exact ratio.

4) Please add vote for supporting Matte Shadows in GPU. It’s a killer not being able to use them.

Many thanks
ben

Can you give us a simple scene which can be used to reproduce the problem?
If it renders fine in IPR mode on the GPU, then it should be something easy to fix.

I can .. could you give me an email or FTP server address ?

thanks
ben

Send an email to support@chaosgroup.com if the scene is big they can give you access to FTP where you can upload it.

Mail sent. For a moment I thought I was going mad as when I tried to isolate the issue for you it didn’t appear. Then I turned on animation and tried outputting a sequence and there it is, works fine for the first frame and then the effect of the sampler or remap vanishes in subsequent frames:

Thank you for sending us the scene. We reproduced the issue and forwarded it to the developers. We will inform you when we have progress on it.

Thanks a lot Zdravko. Could you help with the other questions / issues ?

1) I’m having some strange behaviours with Imageplanes. They sometimes appear in a GPU render and sometimes not. Are they supposed to be supported ?
2) Is there a way to have the Vray background override respect the resolution or film gate when using the IPR ?, so that if I have the film gate visible the background resizes ? .. otherwise it’s impossible to get the background to line up consistently .. it’s position is based entirely on the aspect ratio of the viewport. It doesn’t seem to matter whether I use GPU or not.

If I’m using the IPR I also get strange behaviour with the background in other viewport panels, if I click in and out of the viewport my background resizes depending on which panel is selected. (see attachment)

Many thanks
ben


Are imageplanes generally compatible with GPU rendering ?

Image planes are not supported by RT GPU at the moment.

Is there a way to have the Vray background override respect the resolution or film gate in the viewport ?

The background image depends on its mapping type it can not affect the resolution or the film gate.

Please add vote for supporting Matte Shadows in GPU.

ok

Thanks for the clarification on imageplanes.

>>The background image depends on its mapping type it can not affect the resolution or the film gate.

My point here is that the Vray Background Image works fine in viewport 2.0. But it doesn’t work in IPR .. I think it’s a bug.
Changing the size of the viewport isn’t respected and causes stretching. Whether I use a resolution gate or not the background isn’t mapping correctly.

Thank you for the clarification. I logged the issue in our bug tracking system.

works fine for the first frame and then the effect of the sampler or remap vanishes in subsequent frames:

The issue is now fixed, the fix will be part of the next SP and its available in the latest nightly builds.

Brilliant .. thank you Zdravko !