Merge of KHR_collision_shapes extension #2370
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...s/2.0/Khronos/KHR_collision_shapes/schema/glTF.KHR_collision_shapes.shape.convex.schema.json
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extensions/2.0/Khronos/KHR_collision_shapes/schema/glTF.KHR_collision_shapes.shape.schema.json
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| "extras": { } | ||
| }, | ||
| "required": [ | ||
| "convex", |
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Not a strong opinion but would it be reasonable to make the property not required with the false being the default value?
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| As both the `mesh` shape references a `mesh`, it additionally allows for optional `skin` and `weights` properties, which have the same semantics and requirements enforced by the properties of the same name associated with a `node`. When specified on a `mesh` whose `convex` property is `true`, the resulting collision shape should be the convex hull of the deformed mesh. As collision detection is typically performed on CPU, the performance impact of deforming a mesh in such a use-case is typically higher than inside a vertex shader. As such, use of this functionality should be given careful consideration with respect to performance. When `convex` is `true`, the referenced mesh need not necessarily be convex itself, nor is there any requirement for the geometry to be closed. An implementation must generate a convex hull from the input vertices. | ||
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| Degenerate shapes are prohibited. A `sphere` must have a positive, non-zero radius. `box` shapes must have positive non-zero values for each component of `size`. `cylinder` and `capsule` shapes must have a positive, non-zero `height` and both `radiusTop` and `radiusBottom` should be positive; at least one of the radii should be non-zero. For `mesh` shapes whose `convex` property is `false`, the referenced mesh must contain at least one non-degenerate triangle primitive. For `mesh` shapes whose `convex` property is `true`, the referenced mesh must contain contain primitives with at least four non-coplanar vertices. |
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Please do not use backticks unless explicitly referring to properties. For example:
A sphere must...
Box shapes must...
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Draft of an extension which describes generic, non-renderable shapes suitable for collision detection.
As discussed, we may want to add a
skinproperty to theconvexandtrimeshshapes; realistically, this functionality would likely come with a performance penalty, but there are valid use-cases which would want this ability.