Alpha shadow and ground influence

[César]

Hello,

I am trying to make a render with alpha channel, so I check Alphachannel on the Mesh Preview Kernel, and I check Matte on my orange ground object, but I his color influence is very little, almost inperceptible.

Is possible to keep his original influence with the alpha shadow ?

[kavorka]

Hello,

I am trying to make a render with alpha channel, so I check Alphachannel on the Mesh Preview Kernel, and I check Matte on my orange ground object, but I his color influence is very little, almost inperceptible.

Is possible to keep his original influence with the alpha shadow ?

Until they fix this, what I do is do multiple passes, one for the shadow ect and composite it together (using a mat ID pass). This way, you can put the shadow catcher pass down and then composite the original sphere over that.

[ROUBAL]

You can get colored reflexions on your model in one pass only :

Make sure that you have enabled the transmission node in the Diffuse/matte material of the shadow catcher plane.

Adjust the wanted color in the transmission slot : it changes the color of the shadow and reflects onto your model !

You can even use an image if your Matte plane is UV mapped, and the image should reflect onto the model, emitted from the area of shadow.

The matte plane can also emit light from the shadow area !

[César]

Indeed, the transmission able to color the shadow, but it doesn't make exactly the same effect. The multi-pass seems to be the best to get the same render, or maybe I am doing something wrong ?