[Bf-cycles] Shadow Pass including IBL + mesh Lights (VFX)

[Greg Zaal]

If I understand Thomas correctly, he's simply asking if we can have mesh
lights contribute to the shadow pass, and perhaps environment lighting as
well if possible.

Was it a design choice not to have mesh lights included in the shadow pass?
If so, why? Just a performance issue, or is it somehow useful not to have
them? I don't have much experience in compositing renders with GI, so
forgive my ignorance if the answer is obvious.

Cheers,
Greg


On 10 May 2014 00:27, Brecht Van Lommel <brechtvanlommel at pandora.be> wrote:

> In V-Ray or Mental Ray, is really all you use the shadow pass to get
> this working with IBL? Or do you also use "shadow catcher" or "shadow
> matte" materials? To me it seems what you are really asking for is the
> latter, but maybe I misunderstand how this works.
>
> You can emulate shadow catchers using render layers, but the render
> time is longer than it would be if it was done natively:
> http://www.pasteall.org/blend/29068
>
> It's unlikely that I will work on a shadow catcher material in the
> next months, if someone wants to work on that I can help them, but I
> have other priorities at the moment.
>
> Brecht.
>
> On Fri, May 9, 2014 at 9:44 PM, Thomas Beck <software at plasmasolutions.de>
> wrote:
> > Hi Brecht,
> >
> > as we are creating a lot VFX for the advertising industry and we're
> > converting our projects slowly but steadily to Cycles we're now at a
> point
> > that bothers me and my colleagues a lot: A proper shadow pass that
> includes
> > HDR environment lights and mesh lights.
> >
> > In our production work flow we're taking light probes on the set
> whenever we
> > need to create cg elements afterwards, this way we match the lighting
> > situation perfectly with the real world conditions.
> > When we compose those elements into the shot we're used to use the
> shadow (&
> > AO) pass (in vray / mental ray) and were a bit surprised as we saw that
> > we've got no possibility to mimic that behaviour with Cycles and our
> > lighting requirements as mesh and environment lights are not considered
> in
> > cycles shadow pass..
> >
> > Today I asked DingTo on IRC and he told me that there is a way to take
> mesh
> > lights into account by deleting "ls.prim == PRIM_NONE && " in
> > kernel_emission.h
> > That is already a big leap forward but does not help us on our light
> probe
> > (IBL) work flow...so the question is: Do you know that this is not only a
> > small missing feature but is really crucial for VFX work? I talked with
> > Sebastian too and he's also missing it very much - without this, many
> > projects are very cumbersome to do atm.
> >
> > I searched a bit and was led to the wiki page where you collect all todos
> > and especially this:
> >
> > Option to include environment lighting in shadow pass.
> >
> > http://wiki.blender.org/index.php/Dev:2.6/Source/Render/Cycles/ToDo
> >
> > I really don't want to bash here - just raise the awareness of this
> issue.
> > It's not only a missing feature, it's really a show stopper for us.
> >
> > Is that feature hard to implement? Is there any chance you could tackle
> this
> > issue in a relatively short amount of time? Should I write Ton and beg
> for
> > dev time?
> >
> > If you'd like to talk just drop me a message @plasmasolutions or g+ and
> I'll
> > be online in IRC...
> >
> > Many greetings, Thomas
> >
> > P.S: I'm happy that I'm not the only one with this request but I still
> > wonder why there are not many more? Is Blender rarely used in the VFX
> field?
> > https://developer.blender.org/T34272
> >
> > --
> >
> > ------
> > Plasmasolutions
> > Design | Development | Training
> >
> > Website: Http://www.plasmasolutions.de
> > Blog: Http://blog.plasmasolutions.de
> >
> >
> > _______________________________________________
> > Bf-cycles mailing list
> > Bf-cycles at blender.org
> > http://lists.blender.org/mailman/listinfo/bf-cycles
> >
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