VRAY FOR 3 DS MAX Global Illumination for

V-RAY FOR 3 DS MAX Global Illumination for Exterior Scenes

LESSON INTRODUCTION Orientation • This presentation covers the setting up of GI for an exterior scene using the V-Ray Quick Settings • This lesson topic is approximately 25 minutes in length • This presentation covers all 3 Learning Cycles – Lecture, Demonstration and Activity

GI FOR EXTERIORS • Objective – We will compare different setups for the Global Illumination of an exterior scene • Outcome – You will be able to optimize the quality and speed of the GI calculations for an exterior scene Artwork by Name

TERMINOLOGY • These are some of the terms to be aware of when thinking about Global Illumination – – Global Illumination – a method for gathering light that comes indirectly to the scene. This may be bounced light or light coming from the environment Primary Bounce Engine – this is the GI engine used to calculate the first bounce of indirect light. It has to be very precise because it has a great contribution to the final illumination in the scene Secondary Bounce Engine – this is the GI engine used to calculate all bounces of light after the primary bounce. Because we need to calculate multiple bounces of light here, precision is not as important as speed. Render elements – in CG an image can be split into its composing elements i. e. reflections, refractions, direct and indirect light etc.

GI FOR EXTERIORS Basics • Makes the image more realistic • Adds the light coming from the environment • Adds the bounced light – light that is reflected from diffuse surfaces and further illuminates the scene • Requires additional calculations which slow down the rendering

GI FOR EXTERIORS Quick Settings • Allow us to easily control quality vs render times ratio with a few sliders • GI presets for different scenarios: Exterior, Interior, VFX and Studio • GI drop down allow us to chose between accurate or fast combinations

GI FOR EXTERIORS BF + BF Accurate • This is the most accurate way to calculate Global Illumination • Suitable for wide open spaces – Brute Force as secondary bounce engine allows us to limit the number of secondary bounces • Since GI rays are traced on the fly from the end point of each camera ray we can affect the quality of the GI using only the Shading Quality slider • AA Quality is used to clear out noise that is due to the anti aliasing of the image

GI FOR EXTERIORS IM + BF Fast • The Irradiance Map as Primary Bounce engine speeds up the GI Calculation while maintaining a high quality level • Suitable for wide open spaces – Brute Force as secondary bounce engine allows us to limit the number of secondary bounces • GI Quality parameter is used to control the quality of the GI • AA Quality is used to clear out noise that is due to the anti aliasing of the image

GI FOR EXTERIORS BF + LC Accurate • Very accurate • Use this combination if you want to introduce more bounced light into closed shady parts of the scene • Shading Quality affects the quality of the Brute Force solution • GI Quality affect the quality of the Light Cache • AA Quality is used to clear out noise that is due to the anti aliasing of the image