I have a sphere and a semi-reflective ground plane and I want to get solid reflection alpha on the floor from the sphere.
The ground plane has a semi-reflective material (Reflection of 150 gray color + fresnel) and in the Vray properties menu of the ground object I've enabled Matte object, set Alpha contribution to -1 and enabled Affect alpha. Everything works perfectly apart from the fact that the alpha of the reflections onto the ground plane is not 100% solid white but something like 50% grey (apparently because it is not a perfect mirror with white reflections and no fresnel) which is not what I want.
What I want is to get solid white reflection alpha onto the semi-reflective matte object (the floor) in a single render. Is this possible or do I have to make 2 renders - one with the aforementioned setup and then another one with a 100% mirror material applied to the floor to get the solid white alpha I need?
To get this in a single render I thought that it would be possible with VrayMtlWrapper + VrayOverrideMtl. I applied a VrayMtlWrapper material to the ground and set its options in such a way to get alpha of the reflections. Then I plugged in a VrayOverrideMtl into it so that I can add a 100% reflective material in its Reflect Mtl slot while having the original semi-reflective material in the Base mtl slot. Unfortunately it seems that VrayOverrideMtl doesn't work with VrayMtlWrapper. The alpha on the ground plane disappears if I plug VrayOverrideMtl into VrayMtlWrapper.
The ground plane has a semi-reflective material (Reflection of 150 gray color + fresnel) and in the Vray properties menu of the ground object I've enabled Matte object, set Alpha contribution to -1 and enabled Affect alpha. Everything works perfectly apart from the fact that the alpha of the reflections onto the ground plane is not 100% solid white but something like 50% grey (apparently because it is not a perfect mirror with white reflections and no fresnel) which is not what I want.
What I want is to get solid white reflection alpha onto the semi-reflective matte object (the floor) in a single render. Is this possible or do I have to make 2 renders - one with the aforementioned setup and then another one with a 100% mirror material applied to the floor to get the solid white alpha I need?
To get this in a single render I thought that it would be possible with VrayMtlWrapper + VrayOverrideMtl. I applied a VrayMtlWrapper material to the ground and set its options in such a way to get alpha of the reflections. Then I plugged in a VrayOverrideMtl into it so that I can add a 100% reflective material in its Reflect Mtl slot while having the original semi-reflective material in the Base mtl slot. Unfortunately it seems that VrayOverrideMtl doesn't work with VrayMtlWrapper. The alpha on the ground plane disappears if I plug VrayOverrideMtl into VrayMtlWrapper.
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