How to Make Stereo Cubemap Architectural Renders with V-ray

In this tutorial we’ll look at going from a 2D render (top) to a stereo cubemap image (bottom)

This is the second in a series of tutorials designed to help you use your favorite software and favorite rendering engine to output 360 panoramas. If 3ds Max is your software of choice and V-ray Adv or RT is your rendering engine of choice, this is the tutorial for you. Other 360 tutorials for other rendering engines will be posted in the coming weeks.

Welcome! In this tutorial we’re going to help you take a scene you’ve already set up for V-ray rendering, make a few adjustments, and render out a 360 cubemap image viewable in 360 and VR. We’ll finish by uploading the image to Vizor 360 and viewing it in a VR headset.

Check out the finished project in Vizor 360 below to get an idea of how it looks.

Finished project here, comparing the stereo cubemap with the previous tutorial’s mono equirectangular image.

This tutorial is going to look very similar to the previous one in this series but with two distinct adjustments:

  1. Stereo instead of Mono. That means if you look at the tour in a VR headset, each of your eyes will be viewing a different panorama, thus creating the illusion of a fully 3D experience.
  2. Cubemap instead of Equirectangular. A stereo cubemap is 12 side-by-side images, 6 for a cube for each eye. Due to its more equal treatment of the top and bottom poles of a panorama, cubemaps look less distorted than an equirectangular image, particularly when rendering a primarily orthogonal space.

The primary downside of rendering to a cubemap is, due to its fractured nature, it’s more difficult to understand or add post-processing to the image.

Mono equirectangular render (top) compared to a stereo cubemap image (bottom)

Setting up V-ray

First, create or select a camera in the scene. Note that the camera may be a standard 3ds Max camera or a V-ray physical camera. This camera will be serving as the center point of a 360 render. If you’re using a different camera from the one you created a typical V-ray render with, you will want to ensure your camera has the same settings for color balance, f-stop, ISO, and shutter speed. Your lens and FOV settings will not matter.

Next, set your camera to an average human height if it is not already. Because of the sense of presence afforded by virtual reality, it can be jarring for someone to feel too short or too tall. But what height to pick? Well, anyone who is tall was once short, but anyone who is short has never been tall. 
1.6m or 5’-3” is a good default if you plan on showing your panorama to 
many people.

You will need to rotate your camera to point North, or some direction that you can be consistent with if you create multiple panoramas and need to align their view. Camera rotation won’t affect the content of the render, only how it will be laid out.

Next, insert a V-ray Stereoscopic Helper object anywhere in the scene. The location does not matter.

or

The default settings should already be close to what we want, but go ahead and confirm the following:
Eye Distance: 6.5 cm or 2.56 inches
Focus Method: None
Interocular Method: Shift both eyes
Adjust resolution: Unchecked
Output layout: Top/Bottom
Panoramic Pole Merging: Top and Bottom Merge Angle both set to 60.0

Next, let’s change some render settings. Press F10 on your keyboard to bring up Render Setup. Change the Output Size to 18432x1536 and pick a place to save it. Under the V-Ray tab, choose camera, then set type to Cube 6x1 and uncheck Image Filter.

(L) Camera direction settings, (M) Output settings and (R) Camera settings

That’s it! Now press Render, and you should see 12 square images being rendered in a row, the first 6 for the left eye, the second 6 for the right eye, each square at 1536x1536.

Note if using V-ray RT:

If you are using V-ray RT, this process is almost identical with two simple adjustments:

  1. Don’t use or disable the Stereoscopic Helper.
  2. Under the V-Ray RT tab, then V-Ray RT section, set:
    Stereo mode: Left/Right
    Output layout: Top/bottom

To share your image on the web or create a virtual tour, use the Vizor 360 editor, which will allow you to link scenes, annotate your images and more.

This article was brought to you by Vizor — the most accessible WebVR solution for all devices. Our VR tools are intuitive and easy-to-use, so you can create beautiful WebVR experiences to delight and engage your audience.

https://vizor.io/