GI intensitiy on footage

[BoltThrower]

Hi,

 

First excuse my english

 

I use V-Ray with 3D-Max and have the following problem:

I'm trying to get some light on my movie. In principle that isn't a problem: I set my video as the environment map (AVI-File), create a plane as my virtual ground and put a VRayMtlWrapper (matte surface) material on it (to receive GI). Then i create a VRayLight, set the GI in the renderer active an render the scene. And now the real problem: i can only see some light on my plane if i move the light realy near to the plane, it seams that the light decay (only on this plane, beacause the rest of the scene is ok) is to high... to check "no decay" in the light properties has no positive effect... also if i incrase the light multiplier or incrasing the "Receive GI" amount of the wrapper mtl. has no big effect (it only makes the light brighter and doesn't decrase the decay).

Incrasing the size of the light (sphere) is the only way to get more light on the plane, but then i have a problem with lighting the other geometrie in my scene correctly... and if i check "Normalize intensity" the light on my plane disappears completley... i can't adjust to many global render settings like GI intensity or boost the primary bounces because the rest of the geometry is rendered well...

 

is there a way to incrase the diffuse light on my wrapper mtl. matte surface plane with GI? or is there another way to bring correct light on my real movie background?

 

i hope my problem is understandable and thank's a lot for your help