Workshop 4b & Postgame Arch 200c 2014 Fall
Course	Arch 200c
Date	2014/10/30
Learning Objectives	Intermediate topics in architectural visualization. This workshop presents an in-depth treatment of materials and textures in VRay. Emphasis is placed on the authoring of bespoke over generic textures, and the application of these textures to 3d surfaces using color, opacity, and displacement channels.
Agenda	VRay II (60 m) In-Class Exercise (60 m)
Uses Tool(s)

Postgame Review

Congratulations on making it through your 200a presentation! Today we'll pinup work you presented for this review, and take some time to go over comments you received from the jury regarding how well you applied what you've learned in 200c. Please have all relevant work pinned up and ready to discuss at the start of class

VRay II

Materials and Textures Overview

Materials are physical properties of objects. For instance, properties such as transparency, reflectivity, refraction etc. can be described by different materials. Textures are images / bitmaps that represent the color or pattern of the material. For instance glass is a material that has transparency, reflectivity and refraction but the texture of glass can be described by its color, for example a blue glass, a green glass etc. An interesting thing to keep in mind is that, besides the appearance of an object in terms of pattern and coloration, textures can also affect the material properties. Later we will examine some examples of textures mapping.

The texture mapping can be affected both by global and local settings.

Materials

You can assign materials in V-Ray you can access either the Material Editor or the object Properties. In order to attribute materials on objects open the material editor and right click on Scene Materials to create a new material. Then create the individual material layers that you wish to add to your scene. The following workflow covers the basic settings to assign materials in V-Ray. Introduction to V-Ray

Texture Mapping

Introduction

Texture Mapping is a method for adding texture to a modeled object. This texture is usually a bitmap or a raster image and it usually represents the material of the modeled surface, so that this material can appear as realistic in the rendering process. Texture Mapping is applied to the surface so that every vertex is assigned a texture coordinate (which in the 2d case is also known as a UV coordinate).

Assign Texture Map

Texture Mapping is the method that allows the pattern of the material to be mapped correctly in the geometric characteristics of the object. The process can be described through the following steps. 1. Create a new material in the Material Editor and rename it. 2. In the Diffuse panel click on the m button}} tab to access the Texture Editor window and upload a Material Map, which will be your texture. Click on the Preview button to preview the material. 3. Now you should apply a Bump texture the same way you applied the texture to the Diffuse layer. You can add texture maps to any material layer.

Scale and Orientation

After you have created a material in the Material Editor and applied it to an object either via the Material Editor or from the Properties menu you now have to adjust the scale and orientation of the texture. You can affect the texture scale and rotation angle by clicking in the m button on the material layer that you wish to add a texture map to. The Texture Editor will appear and then you can adjust the scale and rotation of the texture. Mind that these are global setting and will affect the material in every object that the material has been applied to.

If you want to affect the texture in your objects individually you can do that by accessing the Properties menu.

Scale and Orientation is very important in Texture Mapping, because otherwise it can create undesired, unrealistic results. Here are some examples to be avoided.

The following workflow covers the basic steps of a rendering procedure in V-Ray.

The Basic Vray Rendering Workflow

Displacement Maps

Displacement Maps is a similar process to Bump Maps and it allows you to affect the 3d texture of your modeled object, by using a black and white image. According to the black and white texture of the bitmap image the Displacement process maps the contrast of black and white pixels to a variation of height parameter, in order to create a 3d texture based on the initial texture of the image.

Transparency Mapping

Transparency Mapping is a method to create transparent material based on the Alpha channel of a bitmap image. Transparency Mapping allows you to mask your geometry with the Alpha Channel of a bitmap image. this means that parts of the image hat are black will render with a transparent material in the scene.

Analogous 2012 Session: The above content roughly corresponds with this class session from two years ago.
Analogous 124a Session: The above content roughly corresponds with this class session from Summer 2014.

Applying Hand Drawn Textures to Rendering: This workflow builds off of the workflow Creating a Shadow and Linework Rendering to apply textures specifying materials to the surfaces of the model. Emphasis is placed on creating the hand drawn textures using ink and paper, and using the scans of the texture(s) applied over the surfaces to add more detail and information to a rendering
Creating Composite Materials Using Image-Maps in Vray: Using the facade of the de Young Museum as an example, this workflow demonstrates how to use custom-generated image maps to define composite material "layers" in V-Ray. Using the material editor dialog, we will edit the transparency, diffuse, and displacement layers to create the pattern of punches across the material, alter the color using an image map, and simulate the bumps of the material.