Render Mask : Gysmos

[Sbrusse]

Hi guys,
we often need to amend changes upon animated shots.

to crop render a portion of the image during a animation we have two options :
1) link a black and matte shadow plane close to the cam and animate a whole in it to only reveal what needs to be rendered (old trick but kind of works). It's quite time consuming (and creates issues of aliasing when using MB)
2) Create a box in 3D space around the space that needs to be rendered (big enough to capture shadows etc), isolate it, and render that box as a animation as white against black to create a animated mask. Then load that sequence as a render mask and render out the shot. This also create aliasing issues but it's fess time consuming than the first solution.

What I would like is to do option 2 in one step :
Create a geometry that would act as a gysmo (not renderable, not visible, etc) but that tells the render mask what pixels he needs to render.
This way, I can quickly draw geos in 3D that will act as containers of what portion of 3d will be rendered, and that will stick in 3d space the render mask during the animation.

This would improve hugely our day to day workflow

Hope this make sense
Stan

[instinct]

Doesn't VRaySphereFade do just that already?

https://docs.chaosgroup.com/display/...VRaySphereFade

Cheers,
Thorsten

[Sbrusse]

Yes kind of, but :

1) It's works on a section of the geometry but not relative to the screen, so if you have objs that goes in front, it cuts it out, I would need it to render the gysmo area as if the gysmo was isolated :


in this example, the chandelier, table, etc needs to be rendered as well and not being alpha out.
If I draw the shape of the gysmo as a render mask, they would be rendered as well.

2) it only works with gysmos, not arbitrary geometry, so more complicated shapes than box/sphere/cylinder can not be used.

3) it's located in the atmospheric tab, not in the render mask section, would be easier to have everything in the same spot.