Hi Kent,
you probably know by now, but I got this from GPT when passing on your query about the location of the Generated-data in the Texture Coordinates-node:
On-the-Fly Calculation:
The data for Generated coordinates is not stored in a specific location but is computed in real-time when the material is rendered. This ensures that the texture mapping adapts automatically if the object's shape changes.
Not Stored in Mesh Data:
Unlike UV coordinates, which are stored as part of the mesh data, Generated coordinates are a result of a procedural calculation and do not occupy additional space in the mesh's data structure.
Here's the full answer:
In Blender, the "Generated" coordinates provided by the Texture Coordinate node are procedural and computed on the fly. This means that they are not stored as specific data within the mesh or object but are generated dynamically based on the object's bounding box when the material is applied. Here's a detailed explanation:
What Are Generated Coordinates?
Generated coordinates are a type of procedural texture mapping that automatically maps textures onto 3D objects based on their bounding box. These coordinates are consistent regardless of the object's shape or topology and are particularly useful for procedural textures and shaders where traditional UV mapping is not necessary or would be cumbersome to set up.
How Are Generated Coordinates Computed?
The "Generated" coordinates are calculated using the object's bounding box, which is the smallest box that fully encloses the object. Each vertex of the object is assigned a coordinate based on its relative position within this bounding box. The coordinates typically range from (0,0,0) at one corner of the bounding box to (1,1,1) at the opposite corner.
Where Is This Data Stored?
On-the-Fly Calculation: The data for Generated coordinates is not stored in a specific location but is computed in real-time when the material is rendered. This ensures that the texture mapping adapts automatically if the object's shape changes.
Not Stored in Mesh Data: Unlike UV coordinates, which are stored as part of the mesh data, Generated coordinates are a result of a procedural calculation and do not occupy additional space in the mesh's data structure.
Advantages of Generated Coordinates
Consistency Across Objects: Since they are based on the bounding box, Generated coordinates provide a consistent way to map textures across different objects, making them ideal for procedural materials.
Ease of Use: They eliminate the need for manual UV unwrapping, which can be time-consuming and complex for certain models.
Automatic Adjustments: Any changes to the object's geometry automatically update the Generated coordinates, ensuring that the texture mapping remains accurate.
Example Use Case
Generated coordinates are often used in procedural shaders where the texture needs to adapt seamlessly to changes in the object's geometry. For instance, applying a wood grain texture to various furniture pieces would be straightforward with Generated coordinates, as the texture would adjust itself according to each object's size and shape.
For further information and detailed examples, you can refer to the Blender Manual and various Blender community forums where artists share their use cases and setups involving Generated coordinates.
I do find it weird when stating that "it's not stored in a specific location".
It's still data that exists, so it need to be stored in a variable somewhere, even though it's temporary.
