3D Materials and Textures PDF

AS2209 APPLYING MATERIALS AND TEXTURES Materials. Image retrieved from substance3d.adobe.com Materials and textures are the most crucial elements of 3D design. These are focused on achieving the best design of the model. More...

AS2209 APPLYING MATERIALS AND TEXTURES Materials. Image retrieved from substance3d.adobe.com Materials and textures are the most crucial elements of 3D design. These are focused on achieving the best design of the model. Moreover, materials and textures also play an essential role in developing prototypes. When specific materials and textures are used in the modeling process, it helps determine the final product's appearance. It helps to turn the concept into reality. Few objects in the real world have completely uniform surfaces. Instead, most have patterns, color variations, or flaws— for example, the rings in wood or the feeling of brick on a wall. With materials and textures, the visualization in computer-generated 3D looks natural and realistic. Depending on the type and style of visualization, 3D graphic designers use different methods of creating materials and textures. MATERIALS BSDF Material. Image retrieved from r/GraphicsProgramming Materials are applied to 3D objects and significantly impact the final model. Materials can have a wide range of properties. It is a combination of all elements that define the appearance of the material and the final appearance of the objects given the material. The materials include different features that define the model’s final appearance. These features include: Color – Also known as the “diffuse” channel. This determines the RGB color of the material, and this color is the basis of all further calculations. 02 Handout 2 *Property of STI  [email protected] Page 1 of 5  AS2209 Alpha/Transparency – This material setting allows more light to pass through than is reflected, making it “visible” and will enable you to see things behind it. A classic example is glass elements that have a high transparency parameter. Refraction (IOR) – In other words, the refractive index. It is a child parameter of color and transparency. With refraction, elements behind a transparent object like glass appear distorted, just like in reality. Gloss – Gives the object a glossy appearance and is mainly used for wooden or stone elements. Specular – This is the amount of direct reflection of a light source on an object. It is the difference between a matte finish and a shiny finish, but it is not the reflection of the environment itself. Reflection – This is the amount of reflection of the real-world environment around the material. It acts like a mirror and can be colored to act like it has a filter on top. Luminosity/Emission – This is how much light is emitted by the object's surface. No object other than a light source should have luminosity in order to preserve realism. Instances that use luminosity include lamps, neon lights, fire, LCD screens, etc. Subsurface Scattering – This is the amount of light coming into a surface and bouncing inside of it. It acts like a localized luminosity source inside the object, like your hand with a flashlight behind. The material allows designers to determine how light affects an object. It determines the optical properties of an object, its color, opacity, and whether it is matte or glossy. In addition, it defines things such as the amount of light absorbed and reflected by the object. TEXTURES Textures. Image retrieved from substance3D.adobe.com Textures are images that are used to coat 3D objects. The texture can be any conventional JPEG, PNG, or TIFF image file. For example, a brick wall photo can give a 3D model a realistic red brick look. Some objects will also use multiple textures, such as in video games, wherein terrain may contain grass texture, road texture, and rock texture. The texture is applied to the 3D model with the material wrapped around the 3D model using special mapping tools. The surface will not override material settings. Instead, it will work with an existing material setting, breaking its uniform pattern. With this, the visualized object takes on an even more realistic look. You can’t texture an item that doesn’t have a material. The texture is only an image; a material is needed to apply it to an object. 02 Handout 2 *Property of STI  [email protected] Page 2 of 5  AS2209 PROCEDURAL TEXTURES Procedural textures are an algorithmic way of creating a texture. Unlike a bitmapped or image texture, in which the texture is represented as a bitmap, a procedural texture creates the texture mathematically. Although not widely used, this method is resolution independent and can create more precise texture, especially if there is varying depth to the objects being textured. There are many different types of procedural texture generators in 3D programs, but the most common and heavily used are noise and gradient generators. One thing to keep in mind is that these are very general terms; in each 3D program, the terms will be slightly different. The important thing is to know what they do and what kind of images they produce. Noise Generators Noise generation is the creation of randomness in a 2D image. There are usually several types of noise generated by varying equations. Fractal is one of the most common types of noise, with Perlin and Marble being two other options. This random generation of pixels can be animated over time, which allows the information to be used for multiple applications Procedural Noise. Image retrieved from docs.chaos.com Gradient Generators A ramp, or gradient, is another type of procedural texture, and it consists of a gradual change from one color to another. Ramp Texture. Image retrieved from docs.chaos.com 02 Handout 2 *Property of STI  [email protected] Page 3 of 5  AS2209 BUMP MAPPING Different Bump Maps. Image retrieved from pluralsight.com Bump mapping is a process by which a texture, or texture map, is applied to a surface in a 3D computer graphics program to create greater detail on that surface. A bump map is typically used to add a greater amount of surface dimensionality and detail, such as bumps, ridges, scratches, and other details that affect the smoothness of a surface. Such mapping allows an object to appear more realistic without increasing the number of polygons in the object. Bump mapping is typically accomplished through traditional bump maps, normal maps, or displacement maps. Bump Maps Bump maps create the illusion of depth and texture on the surface of a 3D model using computer graphics. A bump map is one of the older maps, and the details it creates are fake. Typically, bump maps are grayscale images that are limited to 8-bits of color information. They are images that represent height values using a 256-color gradient from black to white. Black means that it’s indented, white means that it’s extruded, and gray means that the surface of the texture is Bump Map. Image retrieved from pluralsight.com at the same height as the model, meaning that it doesn’t change anything. Bump maps have generally been phased out in favor of normal maps because they can store more information than bump maps. A bump map can only show height information, whereas normal maps can also show angle information. 02 Handout 2 *Property of STI  [email protected] Page 4 of 5  AS2209 Normal Maps Normal maps can be referred to as an updated type of bump map. Similar to bumps, the details it creates are also fake. Normals maps are used when you want to add tiny details to your model in a way that doesn’t destroy performance. Normal maps are mostly used in computer games to add details to models while keeping a low poly. In a process known as “baking,” normal maps are created based on a highly Normal Map. Image retrieved from pluralsight.com detailed version of an object and then applied to a low detail version of that object to create a more realistic appearance with fewer polygons. Displacement Maps Normal maps give models fake depth; displacement maps give models actual depth. It is basically a bump map, but it is made to displace and manipulate actual geometry, meaning that shadows and silhouettes are also affected. The lighting will also look as accurate as having modeled displacements. Unlike bump or normal maps, a displacement map will also add significant time to your renders. Displacement Map. Image retrieved from pluralsight.com References 3Dwombat. (2019). Material attributes & properties. 3D Wombat. Retrieved from https://www.3dwombat.com/blog/career/material-attributes- properties Difference between displacement, bump, and normal maps. Pluralsight. (2019). Retrieved from https://www.pluralsight.com/blog/film-games/bump- normal-and-displacement-maps Glawion, A. (2022). Normal vs displacement vs bump maps: Differences and when to use which. CG Director. Retrieved from https://www.cgdirector.com/normal-vs-displacement-vs-bump-maps/ MATERIALS AND TEXTURES IN 3D GRAPHICS – DIFFERENCES. Product and architectural 3D visualizations - DOUBLE PRISM. (2022). Retrieved from https://2xp-studio.com/materials-and-textures-in-3d-graphics-differences/ Understanding materials and textures. XO3D. (2022). Retrieved from https://www.xo3d.co.uk/understanding-materials-and-textures/ Wiesen, G. (2022). What is bump mapping? Easy Tech Junkie. Retrieved from https://www.easytechjunkie.com/what-is-bump-mapping.htm Van Gumster, J. (2020). Blender for Dummies (4th ed.). Hoboken, NJ: John Wiley & Sons, Inc. 02 Handout 2 *Property of STI  [email protected] Page 5 of 5