1. Before we begin do the following:

- Global Switches: Turn off Default Lights.
- V-Ray Image Sampler: Use Adaptive Subdivision (for now)
- V-Ray Indirect Illumination (GI): Make sure GI is turned ON.
- V-Ray Indirect Illumination (GI): Use Irradiance Map (IR Map) for Primary Bounces
- V-Ray Indirect Illumination (GI): Use QMC for Secondary Bounces

- V-Ray Environment: Under GI Environment Check Override Max's and set color to the ambient color of your choice (Scene Dependant)

- V-Ray Environment: Reflection/Refraction: Check Override Max's (this isn't important now but it will be for HDRI lighting)

- V-Ray QMC Sampler: These settings may be a little high for now but we'll get into that later.

- V-Ray Irradiance Map: Set the current preset to custom.

- Make the basic Irradiance Map parameters match those in the image (they are optimized for fast render times)

- Leave all other settings default for now

2. Environment Adjustmnets

Here is an example of what can happen to a scene if the environment is too high. As you can see the entire image looks blown out and oversaturated.

Setting the GI environment to .6 caused the result above.

Note: The "blown out" effect is also due to the Target direct Light in the scene. In combination with lights, high GI Environment multipliers can cause unwanted results. By contrast it is possible to light a scene using only the GI Environment

.

2.1 Increase the GI Environment Multiplier to 1.0 and turn off the Target Direct Light (Direct01)

2.2 Render the scene

As you can see this approach produces shadows that are very soft and undefined. This method may work for you depending on the look you are after. You can add a bitmap to the GI Environment by clicking "None" and browsing to a bitmap of you choice. (Adding a bitmap to the GI environment is similar but but the same as HDRI lighting which we will cover later on)