shadowcaster : depth VS shadow

I'm in a situation where I need to know when a shadowcaster is being used to render the Depth buffer (VS shadow buffer)

Nothing seem evident at this time.

So I wonder if there is some shader constant that can be tested in the vertex shader to implicitly tell me the render usage.

I might be alone on this one, but I would like a shader keyword to differentiate the usage.
Because I want to use a lower resolution "mesh" for the shadow VS the depth.

Because the depth buffer must be absolutely identical to the rendered geometry, but the shadow doesn't need to be ?

 

Code (CSharp):

1. #ifdef SHADOWS_DEPTH
2. if (unity_LightShadowBias.z != 0.0) {
3.     // shadow
4. } else {
5.     // camera depth
6. }
7. #endif

This is what Unity uses internally, but it only works if your lights have a non-zero bias setting. For Unity's internal case they actually don't care if when it's zero it does the same code, so they never added another way to deal with this.

I started a thread on this a while ago to try and find a 100% consistent way to tell between camera and light, but I never found a good one that worked in all cases.
https://forum.unity3d.com/threads/d...dow-caster-and-shadow-receiver-in-5-2.362653/

 

The frame debugger seem to indicate (at least in unity 5.4.0f3) that unity_LightShadowBias is zeroed in the depth pass.

In the shadowcaster I'm now using this

if(any(unity_LightShadowBias)==false) // Depth pass

But I'm concerned that this can break at any time...

Could someone from Unity confirm that this is the official/correct way to write Depth vs Shadow shaders ?