VrayObjectSelect Element

[bleeding_me]

Good Morning friends,

I have a simple scene with a ground, a sphere and a cube. I'm trying to render each object separately so that i can composite into after effects.

I tried using the VrayObjectSelect element to achieve this.

What i did was assign object id to each object. Then i went into render elements and created 3 VrayObjectSelect element, each one with a differente ID (1,2 and 3). But after the rendering, each channel has the correct object rendered but all the other objects appear black.

The result i was trying to achieve was in each channel have the correct object rendered and all the others not seen (maybe transparent).

Am i doing something wrong ?

Regards,
Bleeding_me

[vlado]

But after the rendering, each channel has the correct object rendered but all the other objects appear black.

The result i was trying to achieve was in each channel have the correct object rendered and all the others not seen (maybe transparent).

Hm, what's the difference between the two things?

Best regards,
Vlado

[bleeding_me]

Hi vlado,

thanx for your reply...i'll try to explain the difference (note that i'm not a pro ).

When i use render element VrayObjectSelec, i create 3 elements, one for each object. After rendering the following images are the VrayObjectSelect channel from Vray Frame Buffer:

Object Rendered "Ground" (Element VrayObjectSelect_3)


Object Rendered "Cube" (Element VrayObjectSelect_1)



Object Rendered "Sphere" (Element VrayObjectSelect_2)


As you can see the object that is supposed to render in each element is ok. The cube is rendered in Element VrayObjectSelect_1, The Ground is rendered in Element VrayObjectSelect_3 and the Sphere is rendered in Element VrayObjectSelect_2. But in each one, the objects that are not supposed to render are black. For example when the object to be rendered is the ground (element VrayObjectSelect_3, 1st image) the other 2 objects (sphere and cube) are black. I didn't want (i'm not sure this is possible this way) them to appear, only the shadows and reflections.

As you can see in the next images, i made 3 separate renders using the "visible to camera" option in the object properties.

Rendered Object "Ground"



Rendered Object "Cube"



Rendered Object "Sphere"

[Donald2B]

The only way to get those elements out is the way you did the second set of renders. AFAIK, an object behind another will always be "blocked" due to the object in front when trying to render in one pass.

What is the end goal you are trying to achieve?

[bleeding_me]

Hi Donald2B and thank you for answering.

The goal here is to import to after effects and be able to change parameters for individual objects, like color balance .

[Donald2B]

If that is the case, then I would render out the various passes and then put them back together inside of AFx. Use mattes for the objects you want to be able to adjust. Then you can have total control over the diffuse, reflections, refractions, etc. I use nuke for all my compositing, but I would assume that AFx can do it also.

I believe Christopher Nichols posted a tutorial on how to set all of this up. http://www.chaosgroup.com/forums/vbu...-a-Vray-render

[instinct]

Keep in mind that mattes only works to a certain extent. Unless you render deep data.

[Donald2B]

I've not run into many problems, yet. What would be the limitations?

I'm currently using 32-bit exrs in Nuke. What is the deep data you speak of? Can I start rendering to that now, or do I need additional software?

[bleeding_me]

Thank you guys for your help.

I went throught the VrayObjectSelect Element and tried changing the layers in After Effects (and i did )..so here a preview of the real project of mine ...what do you think ?

Next step is to render HiRes and make the compo in AE .

[Donald2B]

Other than when that truck hits the first bump and completely destroys the front flares, not too bad.