Week 2 – Material / Intro to Light Systems 124B 2013 Summer
Course	124B
Date	2013/07/03
Learning Objectives	This session will introduce the use and creation of scene materials and will provide a brief introduction to simple lighting systems. We will explore the relationship between site, building and experience through ray traced representations, material development and overlay with collage techniques.
Agenda	Material Editor Composite Materials Image Mapping Texture Mapping Transparent Materials Emissive Materials Lights Bloom / Glare Materials Introduction to Lights Point Light Spot Light Directional Light Exercise: Create and Assign materials to the 3D model of the Barcelona Pavilion. Assignment: Create and Assign materials for your Sukkah model. Visit the Point Bonita site, do a site survey and obtain the necessary information to assign materials to the 3D model of the site. Create a connection (above, in, or on the site) between the site and your Sukkah model.
Uses Tool(s)	Rhinoceros , VRay

In this session we are going to explore the materiality of digital models. We will introduce VRay , a rendering engine for Rhinoceros. We will introduce the development of composite materials and we will learn to manipulate layer parameters to specify material characteristics of 3D objects.

Schedule

Introduction to VRay

Material Editor
Composite Materials
- Diffuse Layer
- Reflection Layer
- Refraction Layer
- Maps
- Object Mappings

Interface

The toolbar for VRay consists of the following buttons (listed from left to right):

Material Editor: Create, edit, and assign materials to objects.
VRay Options: Edit VRay settings and load preset settings. Options shown here include settings for Camera, Output (image), Environment, Displacement, and Indirect or Global Illumination.
VRay Frame Buffer: Open rendering window.
Add Sunlighting System: Create a system based on physically based daylight, or set it to a specific location and time.
Add Infinite Plane: Creates an infinite plane along the XY plane at the Z zero location, creating a horizon.
About VRay: Information about VRay

Materials & Layers

There are two ways to access the Material Editor in V-Ray: from the toolbar and from the Object Properties panel. Using the V-Ray toolbar, left click on the icon that looks like a tag with the letter "M" on it. Or, select the object(s) to create a V-Ray material for. Use the Properties command and select Material from the drop-down menu. Assign by Plug-in and then click Create.

Creating Materials

Open the Material Editor in V-Ray. Right click on Scene Materials and select "AddVrayMtl."

Assigning Materials

Materials can be attributed to both layers as well as individual objects by using the Material Editor. Materials can be made up of different layer attributes (such as texture, transparency, bumps, etc) in effort to not read more than a flat texture mapping. Sometimes these layers depend on a value (such as intensity or a percentage of transparency) while other times they come from a gray-scale image.

You can quickly view what these materials look like by changing the view to Rendered View which offers a simplified version of the texture maps on the object. However many of the details will change once you actually render the image so it is important to test render throughout the process to check your work.

The next step is to attribute the material to objects or layers. Materials can be applied in two ways: from within the V-Ray Material Editor, or within an object's Properties in Rhino.

In the V-Ray Material editor, right click on the material name, and then click on either "Apply material to layer(s)" or "Apply material to object(s)".

To attribute the material to objects or layers in Rhino, select the objects or layers. Then, use the Properties command and select Material from the drop-down menu. Assign the material by Plug-in, and then click Browse to select the desired material (in the case of this workflow, the material is called Screen1).

Editing VRay Layers

Each VRay Material consists of the following:

Diffuse Layers

Diffuse Color: Change the overall color of an object OR texture map an image onto the an object by selecting the "m" box.
Transparency: Change the overall transparency of an object OR map a transparency pattern onto the object. Black is completely opaque and white is completely transparent.

Emissive Layers

Emissive: Changes the object to become an emitter. Change the intensity to affect how bright the light source becomes. Can change color, intensity, and transparency.

$Refraction Emissive Layers.PNG$

Reflection Layers

Reflection: Adds reflection to the object. White is completely reflective (like a mirror) and black is non-reflective. By Default the reflection layer has a fresnel map which varies the amount of reflection based on the viewing angle (notice the capital M next to the Reflection layer). To make more reflective, increase the Fresnel IOR.

Refraction Layers

Transparency: The darker the Refraction Transparency, the more the material references the edges of the objection (although transparent).
Fog Color: Use this rather than Refraction Color to change the color of the transparent material. Fog color is dependent upon the multiplier, the color and the size of the object. Be sure to pick a color that is slightly less saturated that you desire.
Glossiness: Helps change the frostiness of the transparent material. The lower the number, the more blurry the refraction.
IOR (Index of Refraction): Essentially the degree to which the angle of light entering the material changes upon exiting the material. Calculated the light refracted from the tranparent object. Lowering the IOR decreases the intensity of the Refraction settings.

$Refraction Layer Vray.PNG$

Maps

Bump Map: Changes the way the surface texture appears three-dimensionally, changes the surface normal to create the illusion of surface detail.
Displacement Map: Actually changes the way the surface appears three-dimensionally (such as outlines and edges of the surface) to represent a textured surface
Background Map
GI Map
Reflection Map
Refraction Map

Assignment

Create a series of VRay materials that are specific to your Sukkah model. Apply the materials and textures to your model. Visit the Point Bonita site and document the site's textures and conditions. Create a series of 3D objects to complement the given site model. You might choose to break the site into smaller or differentiated surfaces to assign different materials to the complex ecology of the site; you can add multiple geometry layers to overlay multiple textures.

Finally start thinking about how your Sukkah is going to fit in the site. Start thinking about a connection between your pavilion and the site. You can place your Sukkah anywhere on the site model, but you should think about three types of connections: Above the Site, On the Site or In the Site.

Here are some example files with the site topography and a simple site / object connection: