Auto Normalize is a feature that ensures that the weights of all deforming vertex groups affecting a single vertex always add up to exactly one during the painting process.
Understanding Auto Normalize
Based on the provided reference, Auto Normalize plays a crucial role when working with vertex weights, particularly in the context of rigging and deformation. Vertex weights determine how much a specific vertex is influenced by different bones or deformers.
Here's a breakdown based on the reference:
- Ensures Weights Sum to One: When Auto Normalize is active, as you paint weight onto a vertex for one deforming vertex group (e.g., a bone controlling an arm), the system automatically adjusts the weights for other vertex groups affecting that same vertex (e.g., the bone controlling the shoulder or forearm) so that the total influence from all groups equals 1 (or 100%).
- Contrast When Off: The reference states, "When this option is turned off, then all weights of a vertex can have any value between 0 and 1." This means that if Auto Normalize is off, you can paint weights for multiple vertex groups on a single vertex, and their combined value can be less than 1 or greater than 1. This non-normalized state can lead to unexpected deformation results.
Practical Implications
Using Auto Normalize helps maintain consistent and predictable deformation behavior. When vertex weights on a point sum to 1, the vertex's position will be a weighted average of its influence from all contributing bones, leading to smoother and more intuitive movement.
| Feature | Auto Normalize: ON | Auto Normalize: OFF |
|---|---|---|
| Vertex Weights | Sum of weights for all groups = 1 (while painting) | Sum of weights can be any value between 0 and 1 (per group) |
| Deformation | Typically leads to predictable, smooth deformation | Can result in unexpected scaling or artifacts if sums != 1 |
Essentially, Auto Normalize simplifies the process of distributing influence across different deformers, ensuring that a vertex is always fully "accounted for" by the sum of its influencing groups.
