Reflection problem

[shkumbin]

Hi there,
It has been ages since I was trying to find a solution about this simple thing it should be to do, but there is no way I can do it.
Ok basically what I need is to have 1 object reflecting on a floor and the floor to not show in render at all, just the reflection and the object itself with alpha, I dont want the floor to show at all so I can put it in any background I want and it will look like the floor is shiny.

Please help this is a nightmare for such a simple thing!

cheers

[instinct]

Set the floor to be a matte object, turn alpha contribution to -1.0 and leave the reflection amount at 1 in the vray object properties. This way the object itsel is a Matte object, but still renders reflection

Regards,
Thorsten

[trixian]

Could be I'm missing the point, but I,m pretty sure he wants the alpha for the reflection too, which of course Vray still can't do

[shkumbin]

I want the reflection to show in the alpha as well, I dont want the floor to show at all

[Donald2B]

Just thinking out loud here...but would this work: Take the Alpha Channel and Add the ReflectionFilter pass together? The ReflectionFilter is like an alpha, sort of.

I haven't tried it, but it just popped into my head that it might work. Will look into this a little later today if I get a chance.

EDIT: Nevermind...I was thinking about something else and this is Definitely NOT going to work. duh!

[shkumbin]

yeah,

Vlado is there any chance you might sort this out? Definitely would be a winner for motion graphics stuff.

cheers

[vlado]

With SP5 you can get alphas for reflections using the VRayDirt texture in "reflection occlusion" mode (you can put this in a VRayExtraTex element for example).

Best regards,
Vlado

[johnrfraser]

Hi,

I noticed with earlier versions of Vray (don't know if it's still the case) that obejcts with 0% apocity still showed glossy effects...for example, if you made a leaf with an opacity map; if you didn't apply the opacity mask to the reflect channels too, you got reflections beyond the perimeter of the leaf. This should probably work for your invisible floor.
Is this what you're after?