Vray Region Render problem

[b.maio_SGA]

Dear ChaosGroup,

I'm have the latest Vray next (hotfix 1) for Rhino 5 and have been having this irritating problem with the Region render in the Frame buffer.
Here's the description.

I usually save my final renders with the history window in the Frame Buffer. If I have to make changes, I load the render and do a region render on a selected part of the image.
Here's the problem, Immediately after saving the render in the history window and do a region render, it works fine. But if I close rhino after saving it in history, open the rendered image and then do a region render, it never does it in the first try..... it always renders the 'entire scene' again. Only when I stop it, load the scene from history again and then do a region render, will it render the region. It is never in the first try!

Could you please check and provide a fix?

Thanks

Bomching

[b.maio_SGA]

Hi again,

In general, I've found the region render unreliable in remembering a region render command. Sometimes it does not do a region render and starts rendering the entire scene.

[Peter.Chaushev]

Hello, Bomching,

The behavior you described occurs when drawing a region render in the VFB before having done any rendering. Our developers concluded that fixing this may substantially increase the risk of introducing other bugs and have thus left it untouched. They will revisit it in a future update of the VFB.
For now, I can only provide you the following workaround:

1. Open the Rhino scene.
2. Start a quick render and then stop it (no need to wait for it to finish)
3. Open the VFB history panel, load a previously rendered image
4. Draw a region and render once again. The region will be correctly

Kind regards,
Peter

[b.maio_SGA]

Hi Peter,

Thanks for the notification and workaround. I've been doing it as that's the only way. Its not much trouble for most scenes but on large projects that require a lot of pre-calculation, it does push your patience.

Thanks again.

Regards,
Bomching Maio

[Peter.Chaushev]

There is no need to keep the initial render process going for more than a couple of seconds. Here's a step-by-step description:

1. open the scene you wish to re-render
2. hit the render button and close it 2 seconds or so after the VFB appears
3. load an image from the VFB History panel, draw a region and render.

Alternatively:

1. open an empty project
2. set the output resolution to match that of the image you wish to re-render, then do a quick render.
3. load the project you wish to re-render
4. load an image from the VFB History panel, draw a region and it will render successfully.

I realize a workaround with such specifics may sound a bit absurd. Unfortunately, this is the simplest method for the time being.

Regards,
Peter

[Micha]

It would help if the region render started from the Rhino viewport could work like in the past again. From time to time I need a small region rerendered from a fresh opened, complex scene. Starting the scene and stop it for a first preview can need a minute. At VfR2 I used the region render of Rhino.

[Peter.Chaushev]

Redesigning and enhancing the render in window functionality on V-Ray's side is on our to-do list.

Kind regards,
Peter

[Micha]

I opened a scene, opened the frame buffer and load an old rendering from the current view. Than I draw a region and pressed the blue render button of the frame buffer - frame buffer reset to small default size, loaded image gone and nothing happens. Again, old rendering load ... and render button of the asset editor pressed. Renderings start, region is disabled and the whole image is rendered. Both methods doesn't work like expected.

[georgi.georgiev]

Please note that the render button in the VFB does a Render Last command. If this is used when the project is first loaded, the VFB does not have any data in respect to a previous render, so this is expected and normal behavior.

As my colleague has previously advised, the functionality of the VFB will be overhauled and enhanced.

[Micha]

It would help if the region render started from the Rhino viewport could work like in the past again. From time to time I need a small region rerendered from a fresh opened, complex scene. Starting the scene and stop it for a first preview can need a minute. At VfR2 I used the region render of Rhino.

Please don't oversee this isse. It could be great to get it working like in the past.

[b.maio_SGA]

Dear Vray for Rhino team,

Many thanks for fixing this issue in the latest version (May 5, 2020)
I've been able to test this only today, unaware this was fixed. Guess I missed the text in the announcements.
Actually, I had got used to the habit of doing a short render for a few seconds before I do any render. But, I'm so glad this issue is over.... should I say sooner than I expected.

Thanks again!!

Regards,
Maio