Option for double resolution in ZDepth Render Element

[stupendousman_dk]

If you use Nuke to composite, don't use each pass' individual alpha. Use the alpha pass for it in the "end" of the nodes.
This has worked for me for getting rid of that bad and jaggy edge in animations

Tried all sorts of defringing before that with bad results

[HenrikBC]

Did this one get lost in the pile?

I just bought RPManager, so it shouldn't be too much of a hassle for me any longer. But it would still be a nice option to have directly in VRay if possible. Basically just reading the x and y resolution and doubling them - as a checkbox under the VRay Render Element.

[vlado]

It is not as straightforward to implement this; I have noted it down and we will think about it, but it will take some time.

Best regards,
Vlado

[HenrikBC]

Good to know.

How you even manage to get anything done on top of reading + replying to posts and complaints in here is beyond me, but I'm glad it seems to be working out.

[Druski]

I'm pretty sure this could be solved by using an erode filter on your depth element, well in nuke anyhow. Not sure what the equivalent AF filter would be. You objects in the FG that are floating in space need to be contained within the depth map, it won't work every time, but I have had a lot of success using this method.

[titane358]

+1 for this option too !!! congrat HenrikBC for your short !!!

[rfellers]

I've been experimenting with dof in post and came across this thread. I understand rendering it at double resolution, then applying the dof in post, then scaling it 50%. With antialiasing though... I know to turn off the antialiasing filter, but should I also set the image sampler to 'Fixed' = 1? When I do that, thin lines get broken and jump around in the animation. Anyone have any advice?

[HenrikBC]

titane: Thanks!

rfellers:
You will generally have trouble with very fine details. In my experience post dof works best when you have objects placed gradually into the distance - opposed to a shot of some grass in the fg and telephone poles in the far bg (horror!). In that silly example I would render two seperate passes out and apply an out of focus effect to each instead.

Does the Image Sampler change anything when all you're rendering out is a z-pass? I've used the scanline renderer for most of my z-passes actually, to save speed.

[rfellers]

So you do set the image sampler to 'Fixed' = 1?

[HenrikBC]

I don't even touch it - just apply a global override material which is white (or whatever) and disable shadows before rendering out the z-depth pass.

[3DMK]

So you do set the image sampler to 'Fixed' = 1?

Yes....especially if you have opacity maps such as leaves otherwise it won't cut it out properly

NOTE* Turn off anti-aliasing FILTERs as well as turning OFF Filtering for your bitmap that has opacity [Your opacity map should also ONLY BE BLACK & WHITE & not anti-aliased & turn OFF bitmap filter on those types of materials with opacity

Hope this helps

[rfellers]

I don't even touch it - just apply a global override material which is white (or whatever) and disable shadows before rendering out the z-depth pass.

Don't even touch it, meaning you leave it at what? Also, I guess I'm not clear on your workflow. If the z-depth and the color pass are suppose to line up exactly, why not just render it once at double res w/ z-depth channel? It sounds like you render the color pass at 100% res antialiased (then scale it up in post), then render the z-depth at 200% res non-antialiased. If that is what you are doing, it doesn't sound like the edges are going to line up exactly.

Yes....especially if you have opacity maps such as leaves otherwise it won't cut it out properly

NOTE* Turn off anti-aliasing FILTERs as well as turning OFF Filtering for your bitmap that has opacity [Your opacity map should also ONLY BE BLACK & WHITE & not anti-aliased & turn OFF bitmap filter on those types of materials with opacity

Hope this helps

Thanks - that does help.

[HenrikBC]

It sounds like you render the color pass at 100% res antialiased (then scale it up in post), then render the z-depth at 200% res non-antialiased. If that is what you are doing, it doesn't sound like the edges are going to line up exactly.

That's exactly what I do. The reason for not rendering everything out at 200% is speed. And even if you did that, everything would still not line up _perfectly_ because the z-buffer lacks AA. On all the projects where I've applied post dof to a 3d rendered shot - this is the way I've always done it, and been quite content with the result so far.

I have never had a shot where I needed opacity mapped features and no AA - so maybe that's why I haven't worried too much about the bitmap filtering.

Furthermore; On most of my projects, I have made the z-pass by creating an omni light, setting it to ambient, adjusted the far attenuation of the light, linked it to my camera (usually), turned off all other lights in the scene, made a 255 white material and applied it to everything in the scene/global material override using vray and then rendered it out without AA.