Slice rendering without the empty space around it?

[Fredrik Averpil]

Hi,

Today, when slice rendering, you get a big black frame with the slice region in it.
Is there any way to slice render without getting all of the black surrounding empty space, meaning getting a image of the same size as the slice itself?

The reason I'm asking is really because I'm wondering if this could be a solution to a problem we have frequently; RAM peaking.

We had this huge billboard poster render which would peak the RAM and basically take forever to render. We decided to manually split the frame up in several scenes using camera offset values and a lower total rendering resolution for each scene. This would essentially produce slices of the render, but without the overhead black empty space around each slice. And indeed, the RAM was totally fine, not even getting close to peaking RAM.

Another scenario which is quite frequent here for animation is that something needs to be changed in frame and which is very isolated. Here we usually turn on region rendering and render that out on our farm. However, even in this case it would be nice to be able to skip the black empty space around the region if possible.

What are your thoughts on this?
If not possible to do today, maybe a feature request?

If there are problems with GI or other things being calculated so that you will actually see the borders of each slice, a slice margin could be implemented. This is how we approached the large billboard render custom "slicing"...

[tashko.zashev]

Hi,

What about if you render to Vrimg and use the memory frame buffer in preview mode? It will decrease the memory usage by the frame buffer.
Do you have many render elements? What is the final render resolution that you are trying to render?

Unfortunately don't know any way to automatically change the render size when doing split renderers.
The empty are will be rendered very quick without any memory consumption (assume that DMC Min is 1)

Another scenario which is quite frequent here for animation is that something needs to be changed in frame and which is very isolated. Here we usually turn on region rendering and render that out on our farm. However, even in this case it would be nice to be able to skip the black empty space around the region if possible.

Do you mean something like render selected? Where you could render only the object area.

[Fredrik Averpil]

Hi, What about if you render to Vrimg and use the memory frame buffer in preview mode? It will decrease the memory usage by the frame buffer.
Do you have many render elements? What is the final render resolution that you are trying to render?

I am unfamiliar with the "memory buffer preview mode". What is that and how do I enable that?
I'm planning on rendering vrimg via vray standalone (vrscene exported from Maya).

We have approx 10-15 render elements and the resolution is around 10 000 x 10 000 pixels (ridiculous size if you ask me but that is what the client is requesting).

By the way, we all think it's really impressive that V-Ray will at all render these types of resolutions. It's probably the only renderer that would be able to do it and still have it possible within the constraints of production standards. We think you guys are awesome

Unfortunately don't know any way to automatically change the render size when doing split renderers.
The empty are will be rendered very quick without any memory consumption (assume that DMC Min is 1)

I think it could be useful to be able to region render or crop render without the original full image resolution taking up blank space around the region/crop area. Maybe adding a commandline flag -cropMode which would in effect change the resolution of the output?
Would such a feature request make sense to you?

[tashko.zashev]

Rendering to .Vrimg with V-Ray frame buffer set to "None" or "Preview" will save a lot of memory with such a render resolution. You can easily check this in Task manager.
Just set the file output to .Vrimg, then "Memory frame buffer" parameter will be unlocked and change the "Full" option to "Preview". This will work for both Maya/V-Ray and V-Ray Standalone renderers.

I think it could be useful to be able to region render or crop render without the original full image resolution taking up blank space around the region/crop area. Maybe adding a commandline flag -cropMode which would in effect change the resolution of the output?
Would such a feature request make sense to you?

I'm not sure if i understand this right, but there is an option -crop=x0;y0;x1;y1 in V-Ray Standalone available already.

[Fredrik Averpil]

Hi Tashko,

That is really good to know. I wasn't aware of the frame buffer memory setting!

That's it, -crop did exactly what I wanted.
Many thanks