Frequently Asked Questions

This page provides answers to frequently asked questions about V-Ray. Click the question to view the answer.

General Questions

What's the quickest way to update the script?

Go to Render > System tab > Exporter panel and click the Update Exporter button.

Where is the meshlight?

Select the object you want to turn into a light and go to Object tab > Light.

How do you make an object that is visible in reflections but is invisible to the camera?

This can be done when setting up the material. Select the object and in the Object tab, enable and expand the Render panel. Disable the Visible to Camera checkbox, but leave the Reflections and Refractions checkboxes enabled.

How do you make a point light have a smooth transition between light and dark areas?

Set the sphere segments to 0.

Where is the Number of passes option for the Light Cache?

To set it manually, disable the Auto. Num. Passes option.

How do you exclude an object or a material from generating and/or receiving caustics?

Use the Wrapper panel (in materials and objects).

Can I exclude more than one object? I don't see any button to add another one.

You can add object names and also groups separated by a semicolon ";".

Where is the scripts folder on OS X?

It is hidden inside blender.app. Right click and choose "Show content", then navigate to MacOS/X.XX/scripts/startup/vb25

Rendering

When using V-Ray for Blender with the V-Ray for Maya demo, nothing is rendered out when I hit render.

Check the resolution – the demo version is limited to maximum resolution of 600x450.

After applying a VRayMtl to an object it is rendered black.

If you have "black" objects in the render, and get errors like:

warning: Failed to create object of type "BRDFVRayMtl"

or

warning: Failed to create object of type "BRDFCarPaint"

or

warning: [MtlSingleBRDF] No BSDF parameter specified

This means that you are using an old version of V-Ray. Update V-Ray or use a Layered material.

I have downloaded examples from the site, but when I run render I only see the lights. I don't get errors but 13 warnings.

If you see just lights, and the render is completely dark/without any geometry, click Re-Export Meshes before you hit Render.

V-Ray renders broken .png images.

Leave the image compression to the default value of 90%.

There is no V-Ray window on Mac OS X.

There is an issue with the 64 bit version of V-Ray Standalone on Max OS X, so it doesn't have GUI. Use the 32 bit version to have the V-Ray Framebuffer window. Alternatively, you can observe the rendering process by starting Blender from the Terminal. Also, enable the Output panel and enable "Image to Blender" to load the rendered image back to Blender at render end.

The image is not rendered properly when using Irradiance Map and Distributed Rendering.

Make sure you have saved the Irradiance Map file(s) (.vrmap) into a shared folder. You can use a network path when configuring where to save/load the file(s). Other computers on the network need access to them in order to render the images properly.

How do you render a channel with one selected object?

In the Node Editor, go to Add > RenderChannels > Object Select and type the correct ID in the field below. See the Object Select page for more information.

I have a few objects I want to render out separately, but each element has to have the light interactions with the other elements intact. How can I accomplish this while excluding the other elements from the final image?

Select the Camera, go to its settings (Data) tab, check and expand the Hide objects panel, then choose From camera.

How do you quickly render the whole scene with one material?

Go to Render > Globals tab > Globals panel. Enable Override material, and pick a material.

Content

Space Tools

General Questions

Rendering