Texture Coordinate vs Geometry Node

Question

When working with generated texture coordinates I see sometimes the Texture Coordinate (generated) and sometimes the Geometry (Position) node used. What is exactly the difference ?

Answer 1

The Generated and Position outputs each represent coordinate systems. These are often used as texture coordinates for procedural textures since they are 3-dimensional, though they can be useful for other effects as well.

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Generated Texture Coordinates

Generated coordinates are defined by the bounding box of an object, and are unique to each object.

Generated texture coordinates give the bounding-box-space position across the mesh. The bottom, left, front of the bounding box is the origin (coordinates [0, 0, 0]), and the top, right, back of the bounding box is [1, 1, 1].

I use generated coordinates when I need the texturing to transform, particularly rotate, with the object. However when the bounding box is significantly non-cuboidal generated textures will stretch and distort the texturing. In these cases you may need to manually "un-stretch" the texture with a mapping node, or use Position coordinates.

Generated coordinates can also be useful for non-texturing methods, like creating gradients or other more advanced techniques.

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Position Coordinates

The Geometry > Position output gives the position in world-space across the object. The origin ([0, 0, 0]) is the world origin and all other points are simply their respective position in Blender Units relative to the origin.

I like to use Position coordinates to keep uniform texture scaling across with a material assigned to multiple objects with different sized bounding boxes. Using Position coordinates also prevents distorted stretching on objects with significantly non-cuboidal bounding boxes.