VrayMtlWrapper with Alpha 2.2 on a photo causing problems

[daltonsr]

Recently I came across an obstacle I don't seem to find a solution to. I'm making a photo-match using VrayMtlWrapper as material to receive shadows. When using linear color mapping with default settings - VrayMtlWrapper works fine. But as soon as I start tweaking burn and/or gamma settings I get strange results - VrayMtlWrapper is seen as some bright noise over background image. I really like the natural tone of light/shadows getting out of Reinhard set to B=0.25 and G=2.2 (learned from Peter Guthrie) as opposed to linear color mapping which looks more unnatural or too contrasted.

 

Does anyone know how to combine Reinhard method (alpha 2.2) with VrayMtlWrapper to get propper shadow effect on background image without unwanted noise.

See the attached pictures.

 

 

other settings are:

- overall gamma correction 2.2

- HDRI as texture on vray dome light as a light source (multiplier=1)

- ordinary jpeg image as backgorund (environment slot) with gamma 1.0

- and color mapping / affect background = unchecked

- vray physical camera

- VrayMtlWrapper with alpha contribution = -1, matesurface=on, shadows=on

 

 

Thanks, Tom