Mesh Collider

El Mesh Collider toma un Mesh Asset y construye su Collider basado en esa malla. Es mucho más preciso para la detección de colisiones que el uso de primitivas para mallas complicadas. Los Mesh Colliders que están marcados como Convex pueden chocar con otros Mesh Colliders.

Propiedades

Detalles

El Mesh Collider construye su representación de colisión desde Mesh adjunta al GameObject, y lee las propiedades del Transform adjunta para establecer su posición y escala correctamente. El beneficio de esto es que puede hacer que la forma del Collider sea exactamente igual a la forma del la Malla visible para el GameObject, lo que resulta en colisiones más precisas y auténticas. Sin embargo, esta precisión conlleva una mayor sobrecarga de procesamiento que las colisiones que involucran colisionadores primitivos (como Sphere, Box y Capsule), por lo que es mejor usar Mesh Colliders con moderación.

Caras en mallas de colisión son unilaterales. Esto significa que los objetos pueden pasar a través de ellos desde una dirección, pero chocan con ellos desde la otra dirección.

Mesh cooking

Mesh cooking changes a normal Mesh into a Mesh that you can use in the physics engine. Cooking builds the spatial search structures for the physics queries, such as Physics.Raycast, as well as supporting structures for the contacts generation. Unity cooks all Meshes before using them in collision detection. This can happen at import time (Import Settings > Model > Generate Colliders) or at run time.

When generating Meshes at run time (for example, for procedural surfaces), it’s useful to set the Cooking Options to produce results faster, and disable the additional data cleaning steps of cleaning. The downside is that you need to generate no degenerate triangles and no co-located vertices, but the cooking works faster.

If you disable Enable Mesh Cleaning or Weld Colocated Vertices, you need to ensure you aren’t using data that those algorithms would otherwise filter. Make sure you don’t have any co-located vertices if Weld Colocated Vertices is disabled, and when Enable Mesh Cleaning is enabled, make sure there are no tiny triangles whose area is close to zero, no thin triangles, and no huge triangles whose area is close to infinity.

Note: Setting Cooking Options to any other value than the default settings means the Mesh Collider must use a Mesh that has an isReadable value of true.

Limitaciones

Hay algunas limitaciones al usar el Mesh Collider:

Mesh Colliders that do not have Convex enabled are only supported on GameObjects without a Rigidbody component. To apply a Mesh Collider to a Rigidbody component, tick the Convex checkbox.

For a Mesh Collider to work properly, the Mesh must be read/write enabled in any of these circumstances:

• The Mesh Collider’s Transform has negative scaling (for example, (–1, 1, 1)) and the Mesh is convex.
• The Mesh Collider’s transform is skewed or sheared (for example, when a rotated transform has a scaled parent transform).
• The Mesh Collider’s Cooking Options flags are set to any value other than the default.

Recomendación de Optimización: Si un Mesh Collider solo utiliza una malla, puede deshabilitar Normals en los Import Settings, porque el sistema de física no los necesita.

• Updated Mesh Collider limitations in 2018.3

• 2018–10–12 Page amended

• Mesh Cooking Options added in 2017.3 NewIn20173

• Updated functionality in 2018.1

• Updated limitations relating to read/write enabled setting in 2017.3

• Inflate Convex Mesh deprecated in 2018.3 because the new convex hull computation algorithm (Quickhull) is more tolerant towards imperfections in the input mesh.