Header image retrieved from http://abeloroz.deviantart.com/art/Texturing-Practice-379916683
To create a realistic or visually appealing model, texture artists apply surface and colour properties to the complex character / object models created from the modelling stage. The textures themselves are two dimensional image files, applied to the surface of the model through a process called texture mapping. Texturing and shading are used in conjunction to develop the model’s aesthetics depending on style or realism (textures may range from photorealism to flat colours) of the 3D animation itself. Although textures may be derived from photographs, it is common amongst the industry for artists to hand-paint textures in digital programs such as Adobe Photoshop, (Beane, 2012). Programs like Mudbox also allow artists to paint during the modelling process.
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One method of transferring a texture to the surface is through planar projection, wherein an image is projected onto the surface, comparable to how a movie projector projects onto a surface (Chopine, 2012, p. 152), which is then able to rotated or moved until the desired effect is achieved. Once again likening to a movie projector, when using planar projection on a non-planar surface, the may become warped or distorted.
Cube, or box projection, is a method wherein the texture is divided into six individual squares, then folded up into a cube, and projected onto the surface, whilst cylindrical projection ‘rolls’ the image into a cylinder before projection (Chopine, 2012, p. 152).
Retrieved from Chopine, 2012, p. 152.
To add photorealism to the object, algorithms called texture maps (also known as ‘shaders’) are added to apply colour, texture, or specialised surface details such as glossiness, reflectivity and transparency (Slick, 2016), giving them the appearance of an object with three dimensional depth. The UV co-ordinates achieved in the previous step (UV mapping) correspond to the textures laid on the surface of the model. Artists may additionally use UV co-ordinates on a semi-transparent layer as a guide for where to place details (Slick, 2016).
Colour, or “diffuse” maps add colour or texture to the surface of the model, and is the most basic of texture maps. Specular maps, or “gloss” maps can alter the glossiness of the surface, and is particularly useful for shiny surfaces (e.g. ceramics, metals), whilst a bump or “displacement” map helps to indicate impressions or depressions (Slick, 2016). Other maps include transparency and reflection maps (the clues are in the name).
Beane, A. (2012) 3D Animation Essentials, John Wiley & Sons. Retrieved from https://books.google.com.au/books?id=62FrKLO2M3AC&source=gbs_navlinks_s
Chopine, A. (2012) 3D Art Essentials: The Fundamentals of 3D Modeling, Texturing, and Animation. Focal Press.
Geig, M. (2013) Working with Models, Materials and Textures in Unity Game Development, Retrieved from http://www.informit.com/articles/article.aspx?p=2162089&seqNum=2
Slick, J., (2016) Surfacing 101 – The Basics of Texture Mapping. Retrieved from https://www.lifewire.com/texture-mapping-1956