I have a model of an object and a ground
and I need to separate the two into two different render images. First image -- object with a transparent shadow, second image -- ground without an object. Then I need to place the resulting images in Unity on top of each other so that they would look the same as the render of an object unseparated from the ground.
I managed to make a render of the object with a shadow using render layers and a "shadow catcher" feature. But when I try to combine it in Unity or Photoshop with a render of a ground, the shadow looks too dark (much darker than in a combied render). Surprisingly, when I mix an object with a ground in a Blender compositor, the shadow looks exactly right:
So here are the questions:
Is it possible to make a shadow lighter using shadow catcher? I tried to make a shadow catcher material semi-transparent, but the shadow stayed the same. I also tried to fix the issue with adding a third render -- a render of object without a shadow: I placed it on top, the layer of an object with a shadow in the middle (with the opacity of 50% for a lighter shadow) and the render of a ground in the bottom. Unfortunately it renders some artifacts on the fringes of an object. I also tried to make shadow dimmer in Blender compositor using object ID mask, but again it renders some artifacts on the fringe of an object. The same goes with the method of dividing image with a shadow on the image without a shadow and then placing object on top.
Why does blender overlaying method differ from method in Photoshop or Unity? (I tried to convert renders from standard to premultiplied and from premultiplied to standard, but it did not change much).
Is it possible at all to simulate Photoshop blending algorithm in Blender compositor, so that I will have an idea of how the blending would look in Photoshop or unity without using them?
Would be grateful for any advice.