Help rendering part of the viewport

palmer_aif_1b587f57f9

Hey!
I'm currently doing animations with Daz, but I'm having problems rendering just a part of the viewport. Only certain parts of my character are moving, and I'm trying to only render the moving part without changing camera angles and zoom. I render in iRay and then overlay the moving part above the default image in another software (so everything of the rendered animation related to camera view must remain identical). Since rendering takes a whole lot of time, I'd speed up things considerely if I'd be able only to render the moving part (without hiding the other parts) This could easily be accomplished by just changing the viewport size. I tried fiddling with the aspect ratio but can't get it to work. Is there a way to only render a certain part of the viewport, like a small box or something similar, of the image?

Thanks for your help!

Kerya

What about using the Spot render tool? The icon is the camera with an arrow.

Select the tool and then select the Arrow with a Gear (Tool settings) to change the way the Spot render renders and set it to render to New Window.

Now draw a rectangle (Click upper left corner, hold mouse button, move to the lower right corner of the desired area) and it will render in the perfect place inside the full picture.

palmer_aif_1b587f57f9

Kerya said:

What about using the Spot render tool? The icon is the camera with an arrow.

Select the tool and then select the Arrow with a Gear (Tool settings) to change the way the Spot render renders and set it to render to New Window.

Now draw a rectangle (Click upper left corner, hold mouse button, move to the lower right corner of the desired area) and it will render in the perfect place inside the full picture.

Thanks, but that only renders a single image, not an image series, which is what I need.

nicstt

I know what you mean but I don't think it's available in Daz; I was interested as used something similar to what you describe in blender.

It would certainly be quicker if only the parts of a scene which were changed could be rendered.

There is one aspect you could do; presuming the camera angle isn't going to change much, the try rendering without the backgrounds; just use the ground function in IRAY and use an HDRI. It might help but will depend on the lighting being similar to your HDRI, although turning down the HDRI down very low might work? If you only have a couple of figures, this can drastically decrease render times, and you get shadow information saved in the .png. You'd have to play with the lighting to get the two versions; with backgrounds (rooms etc) and infinite space.

sriesch

Can you simply create a second camera that's zoomed in on the part you need, with the render size temporarily set to small values? 

If you need to constantly adjust pick different spots within your view or flip-flop back and forth between the full size and the small size this would't be workable, but if you're just going to do the same spot render repeatedly for a while as you are working on your scene this might be a workaround.

jbowler

You can zoom in to get a sub-rectangle but it will always be in the center of your original image.  If you rotate the lens to try to get an off (lens) axis rectangle you will rotate the focal plane too and the result will have different distortions to the original.  You can correct those distortions by shearing the image however the rotated focal plane is no longer coincident with the original and so the focal distance will only be correct along a line at best.

This is all because Daz does not support architectural cameras; those things allow both the lens and the focal plane to be rotated.  Think about what is happening with an off-axis rectangle; draw a line through the lens to the center of the rectangle then imagine what a standard camera pointing  along that line will do and where the camera focal plane will be.  Sure it is centered on the rectangle you want but it is rotated off the original plane in at least one dimension.

The way to do this in Daz is to mask out the parts of the image you don't need:

1) Render all the key frames; all the frames where you want the whole scene.  This has to be done as single images (you could use ManFriday's render queue).
2) Make a mask; you need a plane parallel to the focal plane of the camera that covers the whole scene with holes cut in it to expose the bits of the scene that move between the key frames.  Probably just some strips like the sliders on a masking frame so that you can move then in the animation to track the moving segments.  Make the frame green, you may need to fiddle with the surface lighting.
3) Now render the whole timeline as an image sequence.  This gives you a series of green-screened frames that can be alpha composited on top of the respective key frames.

I haven't tried this yet, but I just hit the same problem with AniLip2; 40 frames of lip movement and nothing else.  That's just one word.