Matte Shadow Material rendering black?

[Cesar R]

I am wondering why is it that when using the physical units on the mr photographic exposure, the Matte/shadow material renders black?

 

In the only way around this, i so to use a unit-less physical scale, or am I doing something wrong?

[Cesar R]

I wanted to follow up to the post above.

I did a bit more digging around the web and help files and I found out that the physical units exposure will render a non-HDRI background black as there is not enough light information on the image compared to an HDRI background ?

 

All this leads me to believe that unless you are using the MR Physical Sky blackground there is not need to use the physical units and rather use the unit-less?

 

I am curious to learn how do other engine handle this, let say for instance Vray?

[Tommy L]

I think both the matte/shadow material and also all of the VRay matte object options are just there to tease you. Ive tried every combination and every tutorial. Should be so simple but i cant figure out how to get shadow pass that I can use in post. Its either black on black or more black on a bit more black with a black shadow and black in the apha channel. Or white...obviously I can make everything white, thats easy, I just change a setting that i dont know what it does and everything goes white. Ive wasted so much of my life trying to figure out shadow matte channels that I could have learned Nuke by now and been able to do everything the easy way. So if you figure it out let us know.

[thorsten hartmann]

Hi

 

the best Mode for all Effects is unitless mode. Here can you set the correct physical scale Value. The problem is, if you change exposure (Iso,F-Stop,Shutter), change you the physical scale too.

 

What is the physical Scale?

- normaly is White = RGB = 255,255,255 = ( non physical value = 1 )

- in the correct physical mode is White = physical scale

 

for example.

 

- if the sun have 80.000 Energy, is the physical scale =80.000 = White = ( non physical value = 1 )

 

What is the Problem?

 

- if you change ISO,F-Stop or Shutter, change you the brightness of the image. White is now not physical Scale of 80.000, because white is more or less the 80.000. You need the correct physical scale for the exposure settings ( ISO, F-Stop and Shutter).

 

How Fix the Problem.

 

- use Photo Studio and go under Camera-Settings. Click on "delete overbright BG", now calculate PS the physical scale for your exposure settings and all is good. This Option fix the "Render Elements" Problem too!!!

 

Photo Studio: http://www.infinity-vision.de/page/gui-screenshot

 

mfg

hot chip

Edited September 29, 2013 by thorsten hartmann

[Roodogg]

I think both the matte/shadow material and also all of the VRay matte object options are just there to tease you. Ive tried every combination and every tutorial. Should be so simple but i cant figure out how to get shadow pass that I can use in post. Its either black on black or more black on a bit more black with a black shadow and black in the apha channel. Or white...obviously I can make everything white, thats easy, I just change a setting that i dont know what it does and everything goes white. Ive wasted so much of my life trying to figure out shadow matte channels that I could have learned Nuke by now and been able to do everything the easy way. So if you figure it out let us know.

 

My beauty pass in the VFB renders my matte object black with every combination I try. Material with vraymaterialwrapper alpha on and -1. Same in vray object properties. And the shadow /matte material too. going to have to use a studio background with a camera map.