VrayLight (Dome) affecting entire scene

[Markus]

Hi,

I have a little problem with the VrayLight set to DOME mode. Even if I inlcude just a few objects in my scene, it affects the entire lighting setup (irradinace map GI).

My settings in the vraylight are:

checked: cast shadows, Invisible, Ignore light normals, No decay, Affect diffuse, Affect specular, Affect relfection

The rest is unchecked.

I am are doing some thing wrong??

Thanks, Markus

[Markus]

lol... am i the only one !??

can at least someone say:

"Markus.. all is fine here.. you are doign something wrong"

or

"Yes, same shit here as well"

[vlado]

Can you show an image for this? Also are you rendering an exterior or interior scene?

Best regards,
Vlado

[Morbid Angel]

you are being a little unclear about your problem. How exactly does it affect your scene? typically as any light, a dome light will contribute with its own lighting to the lighting which is already in the scene.

[dlparisi]

I can't get it to work correctly here either (max 9 x64, vray sp2). Using include or exclude to have the dome light hit just one object doesn't work it lights the whole scene regardless.

[sv]

Do you mean in reference to the include / exclude list?

edit: what dlparisi said....

[Morbid Angel]

it works for me. Second teapot is excluded by dome light:



though Im on a later vray version.

[dlparisi]

@MA-I assume you have GI off. I get them same result if I set it up that way. If you turn on GI (Imap and LC) and turn off the plane light you'll see the problem. For ease of seeing the problem I recommend placing a box in the scene rather than a teapot. With the box excluded from the domelight, the top of the box should be black becaue no bounced light from the plane should reach that surface. In my tests however it comes out grey (the right teapot and the box are excluded).

[Morbid Angel]

hmmmm...investigating.....

[Morbid Angel]

well I think I know what the problem is. Since the dome light, when gi is turned on, uses a blend between direct and indirect rays to achieve faster rendering, it does not exclude the indirect part, or rather the include/exclude function only works for the direct rays.
Vlado...?

edit:
I have tested it against mental ray, and got same result:

Direct dome light has box excluded


Direct dome light has box excluded but gi (final gather is turned on)

[Neilg]

Could it be something to do with the bounces not being excluded, and only the initial rays?

The dome light hits the ground plane and works as usual - which is correct, then the rays bounced up off the ground are free to act upon the object which is supposed to be excluded as normal GI.

[Morbid Angel]

Could it be something to do with the bounces not being excluded, and only the initial rays?

The dome light hits the ground plane and works as usual - which is correct, then the rays bounced up off the ground are free to act upon the object which is supposed to be excluded as normal GI.

no, what Im saying is that when gi is turned on, dome light does not cast all rays as direct rays. Instead it uses a blend of both gi and direct rays. So, even if you dont have any other objects in the scene, the top of the box will still get illuminated, because its still included by indirect gi.

[Markus]

wow.. lots of postings here.. cool.

OK.. here are a few images.

skylight-off.jpg shows the scene with vraysun and irradiance map + skylight OFF

skylight-on.jpg is the same scene, with the skylight turn ON and ONLY the box INCLUDED.

So, my question is: Why is the vraylight affecting the ENTIRE scene if only the box is included ?

The scene is attached as well: max2009/1.5 SP2. The ZIP need to be renamed to RAR (because of the upload limitation for rars)

thank you guys,
Markus

[Morbid Angel]

wow.. lots of postings here.. cool.

OK.. here are a few images.

skylight-off.jpg shows the scene with vraysun and irradiance map + skylight OFF

skylight-on.jpg is the same scene, with the skylight turn ON and ONLY the box INCLUDED.

So, my question is: Why is the vraylight affecting the ENTIRE scene if only the box is included ?

The scene is attached as well: max2009/1.5 SP2. The ZIP need to be renamed to RAR (because of the upload limitation for rars)

thank you guys,
Markus

As I said before, maybe I'm not explaining clearly.
When a user turns on GI when using dome light, vray will use a mix between "Direct" and "Indirect" rays for primary hit. And when you exclude or include specific objects, vray will exclude them only from "Direct" part of the formula. So, no matter what, all objects will still get the indirect rays.
Actually, from what I understand, its not simple to exclude specific objects from recieving indirect rays in this manner. Because things will get a lot more complicated when GI starts to bounce between objects which include everything and those that include only some rays.

Here is a diagram example of what happens:

Figure 01, dome light is illuminating all objects with both direct and indirect rays as primary hits:



Figure 02. dome light has all objects excluded from illumination, however that is still a direct illumination only, and as you can see, indirect rays still illuminate the whole scene.

[Markus]

I understood what you said Dmitry. But that is a, let me call it, very bad behavior of the dome-light.

But then we need a way to exclude it completly in my eyes. What is the purpose of an include/exclude list, when only half if it is affected?

I am not a programmer, so dont know how hard that is to implement, but that would be really appriciated