Object Property Overrides for Matte Shadows like Redshifts

[emartin8907]

Redshift has an excellent Material Override options that you set it up in a way that only the shadow is visible in the objects reflections & Alpha and not the shadow plane itself.

Currently in Vray we have to plug our HDR texture into the environment overrides to get the shadow plane to be 'invisble' in our objects reflections. This is kind of clunky and does not behave as good.

Here is an example of Redshifts. This is just using an HDR and a area light, no monkey business with Environment Overrides necessary!

[emartin8907]

Here is Vrays. Using Env Overrides and Secondary Matte Shadow Override. Plane is still somewhat visible in reflections. I've never been able to get this to go away and would prefer to not have to use Env Overrides anyways

[emartin8907]

Here is the Vray Scene if anyone is interested in testing.

[yolov]

Hey, I hope to be able to shed more light on the matte shadow (no pun intended) to the best of my ability.
First thing I noticed in your scene is that you have both object properties (although disabled) and mylWrapper on the same object... which is not really a good idea. You should use either or (in the case where the object properties were enabled, of course).

The 'wtf is this' thing is the matte projection, you can set 'matte for secondary rays' to 'without projection mapping' and still be able to use the secondary matte override texture.
Also, I can see the sphere's shadow reflected back perfectly well (it's also visible in your vray image 'with shadow plane').
Not sure how you got the redshift result and I am not knowledgeable enough to judge which one is more correct.

Bottom line is
- don't set a matte surface with object properties and mtlWrapper at the same time
- set 'matte for secondary rays' to 'without projection'
- there's no indication for an issue with the sphere's shadow caught by the matte and reflected back
and you should be good to go.

As a side note - we do realize our 'matte surface' workflow is not perfect and we have certain plans on improving this in the future.

As a side note to the side note - any particular reason why you're using irradiance map and local subdivs? Just curious.

Hope the above helps.

[emartin8907]

Hi Yolov,

Thanks for looking into this.

I usually never use Object Properties on my shadow planes, it was only on because I was just testing out of desperation. But that is good to know to use one or the other.

No reason Gi was set to IRmap.

AHHHHH WITHOUT projection mapping was the bullet I needed. Thank you!!!!!!!!

Look forward to how you guys improve this in the future though, would still be great to not have to use Env Overrides for HDRs.

Cheers!!