Texture

Every game needs a crate texture

Early on textures was simply mapped onto the polygons. Then with the use of multiple textures one could started to blend them in the fixed function pipeline. Now with shaders textures are not so much specific images but rather data that one needs to pick and choose how to use them in the shader. For the details on how textures are used and abused look in the Material section.

Texture Dimension

A texture can be in one-, two-, or three-dimensions. A 2D texture is a image, a 3D texture is a volume and a 1D texture is like a gradient. Each element in the texture is called a texel and to select a texel one use coordinates of the same dimension as the texture. The coordinates normally go from 0 to 1 so [0.5,0.5] is in the middle of a 2D texture. Getting the texel from the texture with a coordinate is called sampling the texture. A texture can also be in the form of a Cubemap.

Texture Size

The size of the texture is how big each dimension is in number of texel's. It's common for sizes to be power of two (64,128,256,512,...) as graphic cards liked it best that way. The size in all the dimensions does not need to be the same. The max size supported depends on the graphic card and available memory. One solution to large textures is to use Virtual Texture that are not all loaded at the same time.

Texture Format

The format of a texture describe what data each texel contain.

Compression

Filtering and Mipmapping

Say there is a textured surface on the screen where each texel is covering one pixel. If the surface move closer each texel with start to cover more then one pixel, known as texture magnification. If the surface move away there will be more then one texel inside each pixel, known as texture minification. In each of these cases a filtering function is used to select what the color of the texel that is sampled from the texture will be. The visual quality can be improved with mipmaps. A mipmap for a texture is a chain of down sampled images of the texture. So a 256x256 texture have mipmaps of size 128x128,64x64,32x32 and so on. When trying to sample a texture the mipmap is first selected depending on the distance to the surface drawn and then the mipmap is sampled with the filter functions. Mipmaps only affect minification.

Texture filtering

Noise

Links

Procedural Stochastic Textures by Tiling and Blending - 2019

MinLod: A Cheap&Simple Method to Increase Texture Details at Acute Angles - 2018

roughness mip maps based on normal maps? - 2018

Conformal Texture Mapping - 2017

Rethinking Texture Mapping - 2017

Mesh Color Textures - 2017

The Implementation Of A Scalable Texture Cache - 2017

Mesh Color Textures - 2017

Rethinking Texture Mapping course notes - 2017

The Next Frontier of Texturing Workflows - 2016

Texture atlases, wrapping and mip mapping - 2013

A Closer Look At Parallax Occlusion Mapping - 2013

Applying Sampling Theory To Real-Time Graphics - 2012

Textures : can we cheat ? - 2011

Reference Guide For the Beginner Artist - 2008

The Art of Texturing Using The OpenGL Shading Language - 2005

Texture Splatting in Direct3D - 2005

Normal Mapping - 2018

A brief history of 3D texturing in video games - 2019

Announcing the NVIDIA Texture Tools Exporter 2020.1 - 2020

Generating Perfect Normal Maps for Unity (and Other Programs) - 2020

World space UVs & Triplanar Mapping - 2020

Texture Generation Part 2: Normal Swizzling - 2020

Texture Generation - 2020

Complex Maps Masks, Details, and Normals - 2019

Alpha Compositing - 2019