make object phantom and matte

[Jordan Walsh]

Im trying to a rendering method I would usually use in vray (and perhaps Im wrong in going about it in this way...)

I want an object to be a matte object (black in render and 0 Alpha) but also be textured (as a constant shader with a texture map) so it will show up in reflection and refractions (secondary rays).

I can assign the object a constant shader with the alpha set to 0 and I get the correct reflections and alpha, but the object shows up in the colour channels.

Im not sure how to combine the two methods.

[woodenduck]

If you go to the object, Render - Shading - and check the Matte Shading box, the object will be matted out (zero alpha) but will still show up in reflections.

If you want reflections only, there is a 'phantom' check box, but this will not give you the alpha matte.

[symek]

Apply your material as usual, and toggle Matte Shading on a Render/Shading Tab of the object. Mattes sets color to {0,0,0,0} for primary rays, but works as usual for secondaries (they are like phantoms, except phantoms are invisible for primary rays).

[Jordan Walsh]

Apply your material as usual, and toggle Matte Shading on a Render/Shading Tab of the object. Mattes sets color to {0,0,0,0} for primary rays, but works as usual for secondaries (they are like phantoms, except phantoms are invisible for primary rays).

Thanks guys, thats the checkbox i was looking for

Now I wonder if there is a way to capture the reflections off said matte object at the same time, like the shadows are captured on a matte/shadow shader.