Vray feature request VFB + VRIMG

[joelly3d]

Problem:
When rendering really large images, sometimes we need to update only a region of the render with changes and don’t want to re-render the whole image. What we’ve done in the past is region render the changes and patch them in After Effects or Photoshop. But I want to render the region and have it save on top of the previous render, but it doesn’t do that automatically – I think it should.

What I’ve been doing is saving a .vrimg and separate render channels (.exr) under frame buffer options. Then if there are changes (and there always are), I load in the previously rendered .vrimg into the frame buffer and render the region. The problem is that upon render region completion, it overwrites the whole .vrimg and individual render channel .exrs with ONLY the region rendered, destroying the previous render. If I want to save the whole image + render channels, I have to turn off automatic save, render, then manually save a .vrimg and then manually save out the render channels individually. When you save automatically from the VFB it adds the frame number (ie “0000”) to every file, but when you save manually, it doesn’t do this which is why I have to save over the old render channel individually. This is problematic because it takes a lot more time and introduces mistakes.

Solution:
When you load a .vrimg into the VFB and render a region, make it to where it saves the WHOLE image in the VFB + render channels automatically, over the old saved files. Not just the new region rendered, but the old .vrimg and region render addition.

[super gnu]

ha.. exactly the opposite of what i was asking recently.. if you use rendermask, it will overlay the new render on top of the previous one. as was pointed out to me, you can change this behaviour in the settings tab, under "previous render"

[PowerCreative]

Indeed, which is helpful if you're using rendermask to define your region to render. Unfortunately that still saves over the old .vrimg + channels. It would be fantastic to render new pixels (region, rendermask, whatever) and have it save on top of the preexisting .vrimg that you load into the VFB, instead of overwriting it with only the new pixels.

[vlado]

That's why we added the ability to load an image as background in the VFB, but it looks like it doesn't work with .vrimg files for some reason - looking into it now.

Best regards,
Vlado

[PowerCreative]

Bingo - thanks, man! That would make my job so much easier.

[PowerCreative]

Just want to piggyback this thread to add one another related feature request and/or bug I found. If I have region render activated and load a .vrimg into the VFB, it will clear the VFB at render time and save just the region at render completion. I was banging my head on my desk trying to figure out what was going on. Ideally, we want to load a vrimg into the VFB to fix a region, so it should not clear the VFB at render start if you happen to have it activated while loading it in. The workaround is easy, though, just turn off region render, load vrimg into VFB and turn it back on. I just don't see a purpose in saving out only the region if you load a whole vrimg into the VFB.

[vlado]

Just want to piggyback this thread to add one another related feature request and/or bug I found. If I have region render activated and load a .vrimg into the VFB, it will clear the VFB at render time and save just the region at render completion. I was banging my head on my desk trying to figure out what was going on. Ideally, we want to load a vrimg into the VFB to fix a region, so it should not clear the VFB at render start if you happen to have it activated while loading it in. The workaround is easy, though, just turn off region render, load vrimg into VFB and turn it back on. I just don't see a purpose in saving out only the region if you load a whole vrimg into the VFB.

Can you break this down into a bit more detailed reproduction steps? I get a bit lost what and when is loaded and what is cleared.

Best regards,
Vlado

[PowerCreative]

Sure thing.

1) Open VFB, toggle region render on and draw a region anywhere.
2) Load/open a .vrimg into the VFB.
3) Hit render, after pre-processing, VFB goes blank except for region area (despite 'previous render' option set to 'unchanged', or anything else). Upon saving, it saves ONLY the region rendered, discarding everything outside of region.

I can see how this would be a hard one to find, because usually you import a .vrimg into the VFB before toggling and drawing a region to render, but I've been swapping out different .vrimgs in the VFB, so my region was toggled on before importing a .vrimg. Let me know if this doesn't make sense or if I can assist further!

[matanov]

Sure thing.

1) Open VFB, toggle region render on and draw a region anywhere.
2) Load/open a .vrimg into the VFB.
3) Hit render, after pre-processing, VFB goes blank except for region area (despite 'previous render' option set to 'unchanged', or anything else). Upon saving, it saves ONLY the region rendered, discarding everything outside of region.

I can see how this would be a hard one to find, because usually you import a .vrimg into the VFB before toggling and drawing a region to render, but I've been swapping out different .vrimgs in the VFB, so my region was toggled on before importing a .vrimg. Let me know if this doesn't make sense or if I can assist further!

Tried your steps but everything seems ok .. How are you saving the rendered image ? If you are saving through "Render Setup/Frame buffer/V-Ray raw image file" it is normal saved .vrimg to contain only the region.

[PowerCreative]

Tried your steps but everything seems ok .. How are you saving the rendered image ? If you are saving through "Render Setup/Frame buffer/V-Ray raw image file" it is normal saved .vrimg to contain only the region.

If this is normal behavior, then I understand. I just didn't see the benefit of loading in a vrimg, rendering a region only to have everything outside of the region discarded and not saved. We usually want the region rendered patch to save with the rest of everything outside of the region. The workaround for me is simple (just turn region off before loading a vrimg) but it seemed like odd behavior to me so I wanted to share it if it was abnormal.

[matanov]

Actually saving through "Render Setup/Frame buffer/V-Ray raw image file" will always save the region only, no matter the order of loading and drawing regions.

[PowerCreative]

That is true, I miscommunicated. After discovering the vrimg save bug from the first post, I stopped automatically saving through VFB and am saving manually 'save all image channels to single file' or individual exrs. When it clears the VFB (with region toggled) it discards non-region pixels making it impossible to save old render plus new render together. An option to keep everything loaded in the VFB and save everything together would be most excellent.