General difficult thins on Vray (shadows, reflecctions, Glass)

[Varribas]

Hi, I'm Victor new on it.
First of all, english lenguage is not my mother tongue so I hope to explain everithing the best I can.

I use to render objects and I've some questions that always are explained on diferents posts being caotic.

So, lets make a post for everybody how to make the scene to render industrial products.

I made a Scene with Vray, with (HDRI and one Spot light). Is these one:
dl.getdropbox.com/u/808038/Final%20Render.jpg
alpha channel: dl.getdropbox.com/u/808038/alpha_chanel.jpg


As you can se there are shadows, reflecctions and also glass(the hateful material) .

The main problems everybody use to have when render on Vray are on it image and I don't know how to solve it.
1st: If you want to se the reflections, the groundplane reflects also the background being not anymore transparent.
2nd: the alpha channel only keeps the shadows, not shadows and reflections.
3rd: Also doing the groundplane transparent losing the reflections it appears on the object reflections.
4th: The glass has a Affect Alpha activated where you can see on the alpha image is transparent but only where the grounplane isn't. So when the glass has the ground plane rear we can not save anymore the transparency of the glass on the alpha channel.

I'm sure there is some trick to make the perfect groundplane. somebody knows how to do it?

On these image you can see all the materials used:
dl.getdropbox.com/u/808038/materials.jpg

I'm sure if we made a post explaining how to made the perfect groundplane material everybody will be so much happy.
Thanks Evrybody also these comunity.

[mike_kennedy]

Often times if I find this frustrating I will do it in Passes and Mix them together the way I want in After Effects (or Photoshop)

[rivoli]

1st: If you want to se the reflections, the groundplane reflects also the background being not anymore transparent.
2nd: the alpha channel only keeps the shadows, not shadows and reflections.

unfortunately at the moment it's not possible to have a reflections matte out of vray in just one pass, as you can for shadows. you'll have to render the scene at least two times and extract the matte "manually". this thread might be of some help:

http://www.chaosgroup.com/forums/vbu...ighlight=matte

3rd: Also doing the groundplane transparent losing the reflections it appears on the object reflections.

that can easily be sorted, just make the ground plane invisible to reflections either through vray's or object's properties.

4th: The glass has a Affect Alpha activated where you can see on the alpha image is transparent but only where the grounplane isn't. So when the glass has the ground plane rear we can not save anymore the transparency of the glass on the alpha channel.

then again, in the vray's object's properties you can set the ground plane with an alpha contribution of 0, and make it invisible to refractions.