Texturing mentor

Here is a touch of france for a change. Let’s texture a wine bottle with our own brand ‘Wineyard Milano’. To begin with we have a very simple bottle ready. Over the next few steps, we will texture, illuminate and produce fake reflection effect. We will use a layered shader. Create a wine bottle in Maya. For the bottle, there are essentially two components here, the glass bottle texture and the ‘wineyard milano’ label. We will basically create both the above and layer them up using a special type of shader called layered shader. To begin with, create a blinn shader and name it glass. Set the color to a very dark red-orange. Also set the Eccentricity to 0.058, specular roll off to 2 and specular color to white. Set the reflectivity to 0.083 as well because we want to fake reflections later on the bottle as we mentioned earlier.

Next up, using the procedure above, texture the chairs. You can select the chair group and apply the material directly. Repeat the process for the cups and the jug on the table. Use a phong shader, set the transparency color value to 0.818. This will make the jug and cups semi transparent. To set the specular highlight correctly, set the cosine power in the specular shading section to 100, color to white and reflectivity to 0.083. Finally texture the table in the same way.

We’ll use this lambert shader to texture the table cloth. Rename the material cloth. Next, middle mouse button drag a file texture node into the work area. Double click the file texture node to open the attribute of the table cloth. Browse and pick furnishing fabrics plaid. Next to use this file as the color of the cloth, MMB drag the file texture node to the lambert created earlier. Click on color from the list that pops up. To see the cloth texture in the panels, click on shading > Hardware Texturing option in the active panel. To use this texture to get the roughness/bump on the cloth, again MMB drag the file texture node to the lambert material and this click on bump. You’ll now see the bump depth to 0.027. To apply this material to the cloth surface, you can either MMB drag it to the cloth surface and right click the lambert swatch in the hypershade and click assign.

In this very first example we can use very basic techniques and simple textures. We will use bitmap textures for a simple example. Although too many bitmaps in the scene can be too heavy on the RAM, however they still remain an important option because they can be custom painted as we will see later in this blog. The procedure for the simple texturing technique is as follows. Open Maya. Take a restaurant scene with a few tables, chairs, a jug and two cups. We will texture this scene using Bitmap textures. Go to window > Rendering Editors > hypershade. The hypershade is a node based shading network editor and it makes the entire process of making shaders very simple.

Shading in Maya is done by means of hypershade. The hypershade features a node based and very easy to use interface for building your material or shading networks. In addition to 2D or 3D procedural and bitmap texture options, Maya also includes utilities which let you modify colors of an existing texture to a certain level in the material network. In addition there are other utilities which can be useful in using sub-maps for different surfaces all bonded together in a single shading network. There is a blend color node which lets you mix two textures and so on and so forth. So, hop right in and enjoy shading.

Maps are nothing but textures. Textures can be either 2D or 3D. The 3D textures come in two types. Bitmap textures and procedural textures are the two types. Bitmap textures are simple image files and they literally wrap around the geometry in the method you specify like a gift wrap. Therefore this is a 2D texture. Procedural textures are computer program which generate pattern like a checker pattern, a gradient, random noise etc. These can be either 2D or 3D.

Blinn algorithm produces high quality specular highlights and is thus suitable for virtually everything which requires a highlight like metal, plastics etc. A shader further defines characteristics like color, shiness or specualirty and glossiness, roughness or bump, reflectivity etc. These properties are then mapped with suitable patterns and visually referred to as textures and maps. Texture maps can be either images or computer generated patterns like checker pattern or a fractal noise pattern which can make the entire task of shading very intuitive.

A shader or a material is a program which holds surface and visibility properties of geometry and is computed by render. A shader also relies on a shading algorithm which defines the specularity. Which in itself can change drastically change the look and feel objects. Anisotropic is used for linear highlights as seen on a brushed material spoon or on a compact disc. Lambert shader features no highlight or specularity and thus can be used for making cloth or dry wood. Phong algorithm produces low quality highlights suitable for organic surfaces like skin, leaves, etc.

Polished surfaces reflect, matte surfaces such as cloth do not reflect. Mirror reflects; wood doesn’t. Even a shiny cue ball reflects. Define how much a surface reflects.
Refractivity is the surface refractive or transparent. Do you see distorted vision as you see through the object like lens, glass of water, frosted glass window etc.? If so your surface has a refractive index of a measure of how much the light beam bends upon entering the medium.
Translucency also referred to a sub surface scattering in Computer graphics. Translucency is when light scatter inside of the surface. This is observed in wax, marble, milk etc.