[REQ] Render Cropped Section

[noyb]

You probably don't need any more feature requests since there is already a huge list - but... here's another one just in case there isn't enough:

Render a cropped section of a scene.
Most renders seem to have a small section that converges much slower than the rest of the scene, so isolating that selection would allow for that portion to continue rendering without having the rest of the scene slow it down.
This would probably work best if you could do a resume on a particular section of the image.

Just something to think about

[pxl666]

i think this is not possible since unbiased renderer has to take into account whole scene - so to render light bounced from objects properly...i might be wrong but i think this is the issue...

[Kram1032]

Well, yes, but the difference is, that the rays can be shot from a smaller pixel depth, which makes it converging faster, anyway (The rays aren't shot from the light-sources but from the camera...)

[Wedge]

This concept has been brought forth in the past...I think it is either too hard to code or not possible.

The entire scene affects the entire scene, right? So how could you ignore parts of the scene for a moment and focus on converging one area? Can some kind of snapshot be taken to see what the converge will likely be in the future judging by the scene state and making this possible? I don't understand. Is this easier to figure out than it appears to me?

If the floor has a shadow on it cast by an object nearby, how can the area with the shadow be converged if we ignore the area that the object resides in that is causing the shadow? Can the renderer assume the details of this shadow judging by the verts/faces of the objects in the scene that cause this shadow and angle of lights?

[Kram1032]

hum... well...
as the camera shoots the rays...
You can clamp the part, where the camera shoots the rays at... (the pixels, which are behind the part, should converge far faster)
Will be far harder with BiDir, though, where both the cam and the light shoots a ray, that meets in the middle...
And under circumstances, the forced parts get brighter and brighter, while the rest is a bit darker... I dunno, if that problem is solved only for a full image or also for parts of it... (It definitely is for full pics)

[OnoSendai]

Hi All,
I'm working on region rendering right now, it's not too hard, although there are quite a few subtle complications regarding Reinhard tonemapping, resume rendering etc..

What I need to know, is what kind of workflow would be useful for the artists out in IndigoLand.

I can either make the entire image size shrink to fit the render region, or I could draw the render region inside a large black image.

How are people expecting to merge a full render, combined with a render-region render? Photoshop? Or is some kind of merging tool desired?

[dougal2]

could indigo load an IGI in the GUI, and render over a portion of it, outlined with a red box ?
then save the whole preview (without said red box) to a new IGI ?

Could indigo be told to render a region only by simply dragging the red box over the preview ?
(Then click off the image to remove the box and resume rendering the whole image ?)

This is the kind of workflow I'm used to in Maya.

[SimonLarsen]

How are people expecting to merge a full render, combined with a render-region render? Photoshop? Or is some kind of merging tool desired?

It would be a waste of time developing some kind of tool, when it's so easily done in Photoshop or GIMP or whetever people use.

Oh, and by the way. Great about the feature. Thanks. It will definitely become very useful.

[dougal2]

I don't like the idea of trying to align regions in PS/GIMP whatever - how many mis-aligned regoins will we start to see ?

[OnoSendai]

could indigo load an IGI in the GUI, and render over a portion of it, outlined with a red box ?
then save the whole preview (without said red box) to a new IGI ?

Could indigo be told to render a region only by simply dragging the red box over the preview ?
(Then click off the image to remove the box and resume rendering the whole image ?)

This is the kind of workflow I'm used to in Maya.

I think I'll leave this kind of stuff to the exporters, and Indigo will just receive pixel coordinates for the rectangle to render.

[OnoSendai]

I don't like the idea of trying to align regions in PS/GIMP whatever - how many mis-aligned regoins will we start to see ?

Yeah... I'm not sure if this is actually a problem, as I don't use PS/The gimp that much.

[dougal2]

hmmm ok. In that case I'm in favour of building a tool to do this - probably too hard to do with the limited API available in exporters.

Can we get the region co-ordinates stored in IGI and PNG metadata please ?

edit: re: mis-alignment. You, I and the experienced amongst us wil have no probs I'm sure, but I'm almost certain it'll become the new recurring topic for n00bs, like normal-smoothing.

[neepneep]

I like the render region frame in a big black box idea...It makes alignment quicker.

Maybe if the black surrounding area had alpha transparency then it would be easy to use merging tools as well.

[OnoSendai]

Yes, I think I'll add the region coords to the IGI format.

[SimonLarsen]

I don't like the idea of trying to align regions in PS/GIMP whatever - how many mis-aligned regoins will we start to see ?

If you have to pixel coordinates it shouldn't be to difficult putting it the right place.

But If you, or anybody else would like to make a tool, then go ahead.
It might be useful for some people.