Option to disable DOF per object - eg. to render glass with rain on live-action plate with baked-in DOF

[HenrikBC]

I would like an option to render with depth of field, but be able to disable it for specific objects (typically a background plate/object with an image on it), for the ability to render eg. glass with rain, or other objects with dof, on top of a background plate that already has baked-in DOF that cannot be removed.
In other words, the objects that have the DOF Disabled property, would just render completely sharp - as if the camera had DOF disabled - but only for these objects.

Maybe a workaround for this already exists and I just couldn't find it? My search got me some results in a Corona forum, but the thread didn't end up with any implementation nor solution, as far as I could tell.

[^Lele^]

DoF is calculated on the scene, via the Camera.
It's simply impossible to turn it off per node.

[HenrikBC]

I see. But is there a possible workaround to solve the use-case as described above?

And happy new year!

[^Lele^]

I see. But is there a possible workaround to solve the use-case as described above?

Entirely unsure.
Other stuff can be composited using render passes (i.e. moblur: render the scene without, and a scene with a single node with, composite.), bot for DoF, i'd be quite skeptical it'd ever work.
Marrying the CoC with the straight render is going to be exceptionally tricky at best, quite likely resulting in artifacts in a number of cases.

You could surely attempt it entirely in post, with deep renders and a post-effect DoF, but that too will prove difficult (refractions, reflections, and such), and the visual results, even when one managed to achieve an overall convincing DoF, would look out of sorts, i'd think.

And happy new year!

Likewise!

[HenrikBC]

Yeah, and one major reason for keeping it in 3D is to get correct refractions thru the glass/water materials. The developer (I think he was) in the Corona thread seemed to think a method was not impossible, but alas the thread never ended on an answer or follow up..

[^Lele^]

Yeah, and one major reason for keeping it in 3D is to get correct refractions thru the glass/water materials. The developer (I think he was) in the Corona thread seemed to think a method was not impossible, but alas the thread never ended on an answer or follow up..

Do you have a link to that thread?

[HenrikBC]

https://forum.corona-renderer.com/in...p?topic=8181.0

They mention it might be possible as a screen mapped bg. That would work perfectly for my example.

[^Lele^]

no, not currently possible. We have some internal prototype, but it was not working well, needs more work

I rest my case.
I'll poke Ondra anyway, see where it fell apart.

I still can't get my head around the marrying of the two circles of confusion: the blurs blend together, normally, so splitting them will *have* to generate artifacts.
For example, if the un-dofed BG was seen through a dofed glass, seems to me to produce an unsolvable case.

[HenrikBC]

I can see that it's tricky - if not impossible. But I also see utility - if it were, somehow, possible.
Just did some experiments. Putting a map in the V-Ray Reflection/Refraction environment slot, set to Screen, is sort of towards my goal - except that besides "bypassing" depth of field, it also bypasses any refractions.

[^Lele^]

It's not impossible at all: it's just quite limited to specific cases not involving reflection or refraction.
If you think of a diffuse-only scenario, f.e., it's trivial to obtain with simple alpha compositing (of the foreground on the backplate.).
But when it coms to those two effects, my head melts trying to find a solution (which is also why i'm not Ondra, or Vlado, or any of our devs, btw. ^^).
That, too, would have to be limited to the BG, in case, as marrying *any* node within some other's CoC would become a source of artifacts the eye would be drawn to immediately.

[HenrikBC]

Let me know if one of the uber-devs comes back with any updates.

[piotrus3333]

it should work per object with multiplier:


cpu only.

edit: heh. DOF not MB. my bad..

[HenrikBC]

piotrus3333 If only it were that easy.