Texture Mapping: Exploring Dimensionality in Computer Vision

By Fouad Sabry

What is Texture Mapping

Texture mapping is a method for mapping a texture on a computer-generated graphic. Texture here can be high frequency detail, surface texture, or color.

How you will benefit

(I) Insights, and validations about the following topics:

Chapter 1: Texture mapping

Chapter 2: Normal mapping

Chapter 3: Bilinear interpolation

Chapter 4: Texture filtering

Chapter 5: Lightmap

Chapter 6: Reflection mapping

Chapter 7: Cube mapping

Chapter 8: UV mapping

Chapter 9: Texture mapping unit

Chapter 10: Technical drawing

(II) Answering the public top questions about texture mapping.

(III) Real world examples for the usage of texture mapping in many fields.

Who this book is for

Professionals, undergraduate and graduate students, enthusiasts, hobbyists, and those who want to go beyond basic knowledge or information for any kind of Texture Mapping.

• Language: English
• Publisher: One Billion Knowledgeable
• Release date: May 14, 2024

Book preview

Chapter 1: Texture mapping

Texture mapping is a technique used to map a texture onto a computer-generated image. Texture might be high frequency detail, surface texture, or color in this context.

In 1974, Edwin Catmull developed the first version of the method.

Texture mapping initially referred to diffuse mapping, a method that simply mapped a texture's pixels onto a 3D surface (wrapping the image around the object). In recent decades, the advent of multi-pass rendering, multitexturing, mipmaps, and more complex mappings such as height mapping, bump mapping, normal mapping, displacement mapping, reflection mapping, specular mapping, occlusion mapping, and many variations of the technique (controlled by a materials system) have made it possible to simulate near-photorealism in real time by drastically reducing the number of polygons and lighting calculations required to build a scene.

A surface map This could be either a bitmap or a generated texture. They can be saved in standard picture file formats, referenced by 3D model formats or material descriptions, and bundled into resource bundles.

Visible surfaces may have 1-3 dimensions, although two dimensions are most common. Texture map data may be stored in shuffled or tiled orders to increase cache coherence when used with contemporary technology. Rendering APIs often manage texture map resources (which may reside in device memory) as buffers or surfaces, and may permit render to texture for additional effects like post processing or environment mapping.

They often contain RGB color data (stored as direct color, compressed formats, or indexed color) and occasionally an additional channel for alpha blending (RGBA), particularly for billboards and decal overlay textures. It is feasible to employ the alpha channel (which may be easy to store in forms that hardware can interpret) for purposes such as specularity.

Multiple texture maps (or channels) can be merged to manage specularity, normals, displacement, and subsurface scattering, such as for skin rendering.

Texture atlases and texture arrays can be used to merge many texture pictures to decrease state transitions on contemporary hardware. They may be viewed as the modern progression of tile map graphics. Modern technology frequently supports multiple-faced cube map textures for environment mapping.

Texture maps can be gathered via scanning/digital photography, produced in image editing tools such as GIMP, Photoshop, or painted directly onto 3D surfaces using a 3D paint tool such as Mudbox or zbrush.

Comparable to putting decorative paper to a basic white box. Each vertex of a polygon receives a texture coordinate (which in the 2d case is also known as UV coordinates). This may be accomplished via explicit assignment of vertex characteristics, manually updated in a 3D modeling application using UV unwrapping tools. The material can also be associated with a procedural transformation from 3D space to texture space. This may be performed using planar projection, cylindrical mapping, or spherical mapping. Complex mappings may take distance along a surface into account to minimize distortion. During rendering, these coordinates are interpolated across the faces of polygons to sample the texture map. Textures can be duplicated or mirrored to extend a finite rectangular bitmap over a greater area, or they can have a one-to-one unique injective mapping from each surface fragment (which is important for render mapping and light mapping, also known as baking).

Texture mapping converts the model surface (or screen space during rasterization) to texture space, where the texture map appears in its undistorted form. UV unwrapping tools often provide a texture space view for manual texture coordinate manipulation. Certain rendering techniques, like subsurface scattering, can be approximated using texture-space operations.

Multitexturing is the application of many textures to a polygon simultaneously.

Texture filtering governs how samples (e.g., when shown as pixels on the screen) are calculated from texels (texture pixels). Nearest-neighbor interpolation is the cheapest method, although bilinear interpolation and trilinear interpolation between mipmaps are two often used alternatives that reduce aliasing or jaggies. If a texture coordinate extends outside the texture's bounds, it is either clamped or wrapped. When viewing textures at oblique viewing angles, anisotropic filtering reduces directional artifacts more effectively.

Texture streaming is a method of employing data streams for textures, when each texture is accessible in two or more resolutions, to choose which texture should be loaded into memory and used based on draw distance from the viewer and available texture memory. Texture streaming enables a rendering engine to use low resolution textures for distant objects and resolve those into more detailed textures read from a data source when the point of view nears those objects.

Detail from a sophisticated, high-resolution model or expensive procedure (such as global illumination) can be rendered as an optimization into a surface texture (possibly on a low-resolution model). Bake mapping is another name for baking. This method is typically employed to make light maps, but it can also be used to generate normal maps and displacement maps. Some computer games, such as Messiah, have utilized this method. The original Quake software engine combined light maps and color mappings on the fly (surface caching).