PDA

View Full Version : Inconsistent behaviour with light excludes and radiosity



Captain Obvious
04-16-2007, 05:07 AM
The first image shows the scene with everything visible. The second image shows the scene with the teapot hidden from camera, but visible to everything else. Notice that it's both reacting with global illumination and casting a shadow. The third image shows the teapot excluded from radiosity and the direct light. Notice how it's no longer casting a shadow, yet it is still taken into account. This seems a little bit inconsistent and counter-intuitive. Also, it's a pain in the arse that we can't exclude objects from radiosity and keep them in reflections, and vice versa.

jameswillmott
04-16-2007, 05:30 AM
Exclude from Radiosity just prevents Radiosity affecting the object, not preventing the object affecting radiosity of other objects in the scene. You'll need Unseen by Rays for that.

Captain Obvious
04-16-2007, 06:40 AM
Exclude from Radiosity just prevents Radiosity affecting the object, not preventing the object affecting radiosity of other objects in the scene. You'll need Unseen by Rays for that.
I know how it works. I'm just saying I don't think it's how it SHOULD work. ;)

Also, Unseen By Rays hides it from reflections and refractions as well.

jameswillmott
04-16-2007, 06:57 AM
Yes, there are no good workarounds for this. We need Unseen by Radiosity don't we?

Captain Obvious
04-16-2007, 07:00 AM
Yes, we do. And separate Unseen by Reflections and Refractions as well. It's very useful.

dpont
04-16-2007, 07:10 AM
Right with you and for request,
but with your teapot sample, occlusion is
also efficient and you could filter both
occlusion & reflections with ray bounces,
because occ uses first bounce and reflection
all bounces above.

Denis.

Captain Obvious
04-16-2007, 07:18 AM
The teapot is not important.

brian.coates
04-16-2007, 08:13 AM
The most intuitive setup would be to have 'Unseen by Camera' mean that an object is unseen by everything.

But like the Captain said, that may not be what you want in all situations...

jameswillmott
04-16-2007, 08:16 AM
Sometimes I need an object which is invisible to the camera but visible to other rays.

Captain Obvious
04-16-2007, 08:17 AM
The most intuitive setup would be to have 'Unseen by Camera' mean that an object is unseen by everything.
Why would that be intuitive?

dpont
04-16-2007, 09:02 AM
Ok the teapot is not important,
and again I'm agree with you,
but I have tested a way to use the
bounce output of Spot node for unseen purpose,
radiosity on, the reflected sphere has
shadow and radiosity but not seen at all:
45286

Denis.

Captain Obvious
04-16-2007, 09:12 AM
That's cool. Can I see the node setup, please? :)

dpont
04-16-2007, 09:19 AM
This is only possible in 9.2 beta, a bit complicated,
the reflected ball is "Unseen by Camera" but
it is not excluded (light, radiosity), radiosity
Montecarlo basic settings (1 bounce),
45287

Denis.

Captain Obvious
04-16-2007, 09:27 AM
Interesting.

dpont
04-16-2007, 09:27 AM
The surface file (for Logic node settings...)
45288

Denis.

brian.coates
04-16-2007, 09:33 AM
Why would that be intuitive?
Well, in LW Unseen by Camera means that you can't see an object even when you're looking right at it, so to my mind if an object can't be seen then it doesn't exist, (at least in relation to the virtual 3D environment).

We could start on the old, "if a tree falls in the woods and no-one hears it..." track but we'd be here forever... :D

Captain Obvious
04-16-2007, 09:39 AM
Yeah, but if you have two options, one called "Unseen by camera" and the other one "Unseen by reflections," isn't it kind of obvious that the first option just disables visibility to the camera, but keeps it in reflections?

jameswillmott
04-16-2007, 04:34 PM
Well, in LW Unseen by Camera means that you can't see an object even when you're looking right at it, so to my mind if an object can't be seen then it doesn't exist, (at least in relation to the virtual 3D environment).

We could start on the old, "if a tree falls in the woods and no-one hears it..." track but we'd be here forever... :D

Wouldn't simply 'Unseen' be more intuitive than 'Unseen by Camera'?

brian.coates
04-16-2007, 11:47 PM
Wouldn't simply 'Unseen' be more intuitive than 'Unseen by Camera'?

Exactly. :thumbsup:

That's what I should have said.

ingo
04-17-2007, 01:15 AM
Lets see ;)

- Unseen by camera : means only visible in reflections and throws shadows
- Invisible : like deleting the object from the scene file
- Unseen by lights : visible but don't receive lights and don't cast shadows, visible in reflections (... and for raydiosity bounce light ?)
- Unseen by raydiosity : visible but don't receive and send bounce light, but direct light (preferably with send/receive raydiosity switch too)
- Unseen by reflections : not visible in reflections but visible for light and raydiosity

Have i overseen something ?

Captain Obvious
04-17-2007, 04:17 AM
I REALLY want separate recieve light / cast shadow from light, and separate receive / visible to global illumination.