Problem with Creating Transparent Background for Product Renders in V-Ray

Hey guys,

I’m having a lot of trouble finding a way to make the background transparent in my product visualization scene.

My goal is to be able to export just the product itself, and the shadows associated with it, so that I can send that file to our graphic designers for them to customize further.

Could someone please explain to me how I would go about doing this?

I am self taught with both SketchUp and V-Ray, so my vocabulary and depth of understanding surrounding those two programs is intermediate at best.

Please let me know if someone can help. I have attached a PNG of the scene in question for everyone’s reference.


Great question. I’m here in Vancouver at 3DBC and the Chaos team is here…I’ll try to ask them and see what their recommendations are and circle back.

Thank you! Please let me know what you find out.

If I were going to do something like this I would create a smooth seamless background something like in the image below. You need the floor and walls to help keep the light in. But I would make the surface an illuminator (wrong term for V-ray I’m sure) so it’s entirely white with no shadows. Then in an image editor I would set the rendered image’s layer to Multiply so the white background appears as transparent. You could, of course, make the background pixels transparent, too.

It’ll be interesting to see what Eric comes back with.

Trying to remember how you do this away from my computer (at 3D basecamp also) , but there are a couple of ways I think you could do this.

If you are saving as PNG file the background should be transparent automatically - however if you’ve used a backdrop of a lighting studio or floor plane , then that is a physical thing. That will show.

If you find the material that you’ve used in the backdrop “fabric” there is somewhere where you can make that material invisible to the camera , but not to the lighting calculations.

Then when you export it as PNG , it should not be there

Most rendering programs have the ability to render with an “alpha channel”. This is what you are looking for. Unfortunately, I don’t know Vray. From what I remember, in the Frame buffer window you have the option to select the alpha channel and save it.

This additional geometry is not necessary. It was a must for traditional photography. Here it is enough to have a fairly large area of white floor and use the white color of the sky in the environment settings. It’s everything. Adding an illumination to the floor material does not make sense - the material will illuminate the model and distort the shadows. And the arrangement of the armchairs in your example also makes no sense. Always position models as far away from walls as possible to avoid unwanted shadows


With the above image, a skilled graphic designer can already get what you need.

What you should be looking at is how to build a shadow-catcher material.
You can look for detailed tutorials online by keywords: “V-ray matte shadow catcher material”.

Basic steps:

  1. Create a generic material and use a light gray color for it.

  2. Create a new wrapper material and use the background material as a base

  3. Set Alpha Contribution to -1

  4. Turn on “Matte” option

  5. Turn on “Shadows” option

  6. Apply the material to faces.


FWIW, here’s a quick example or what I described with a low quality render.

Setup in SketchUp.

Result of rendering after giving the background material Self Luminance. No shadows on the background to deal with at all.

After deleting the white background pixels to end up with transparency. No shadows on the background to deal with.

Line only exports from SketchUp:

The line only images combined with the render with the transparent background.

Very simple process.

This is the breakdown of the V-ray Scene:

In SketchUp

In render


Final PNG Image
Matte background scene

Example studio. There is only one light source, so the Shadows are harsh.
Studio.skp (1.4 MB)

For some reason the Wrapper material works only in CPU render


Are you sure this is what he wanted to achieve OP?

Thank you. This ended up working for what I was trying to achieve.

I searched your key words online and found this link that I used to fill in any gaps in direction:

I know it uses a slightly older version of V-Ray, but it’s still easy to follow.