FastShadowReceiver/Projector/Multiply Without Falloff
These shaders are similar to “Projector/Multiply Shadow” shader which is included in Standard Assets (Projectors). The difference is both of the FashShadowReceiver shaders have “Shadow Darkness” property to control shadow darkness.
“FastShadowReceiver/Projector/Multiply” have FallOff texture like “Projector/Multiply Shadow” shader (the left image). On the other hand, “FastShadowReceiver/Projector/Multiply Without Falloff” doesn’t have FallOff texture. So, the shadow which is far from the projector is still dark (the right image), and this shader is faster than the others.
FastShadowReceiver/Projector/Multiply Diffuse Without Falloff
These shaders take into account normal vectors of a surface like diffuse lighting so that shadows can be more realistic. Also, these shaders can avoid the backside projection problem whereby a shadow is projected on a surface which is not facing to the projector.
These shaders require normal vectors. Don’t forget to check ‘Has Normals’ property in MeshShadowReceiver if any.
This shader is used for debug purpose. It can visualize meshes which are receiving a shadow from the projector.