diff --git a/extensions/2.0/Vendor/EXT_implicit_geometry/README.md b/extensions/2.0/Vendor/EXT_implicit_geometry/README.md index af389bca48..a428185a71 100644 --- a/extensions/2.0/Vendor/EXT_implicit_geometry/README.md +++ b/extensions/2.0/Vendor/EXT_implicit_geometry/README.md @@ -12,7 +12,7 @@ Written against the glTF 2.0 specification. ## Overview -This extension allows mesh primitives to represent renderable implicit surfaces. Typically, a glTF mesh primitive requires `attributes` that supply mesh data, and uses `mode` to indicate the mesh topology. With `EXT_implicit_geometry`, the primitive may omit these properties. The extension's properties will be used instead to infer the implicit 3D volume. +This extension allows mesh primitives to represent renderable implicit surfaces. Typically, a glTF mesh primitive requires `attributes` that supply mesh data, and uses `mode` to indicate the mesh topology. With `EXT_implicit_geometry`, the primitive may omit these properties and instead use the extension to infer the implicit 3D volume. The following example illustrates how a primitive with this extension may represent an implicit box. @@ -43,7 +43,7 @@ Currently, this extension supports the following implicit geometries: - [`ellipsoid`](#ellipsoid) - [`region`](#region) -Each shape is represented by its aptly named property in the extension. Only **one** shape may be defined at a time. +Only **one** shape may be defined at a time. By default, the implicit 3D volume is assumed to fill the entire shape specified in the extension. However, each shape allows an optional `bounds` property to define the subsection of the shape in which the 3D volume is actually rendered. For instance, while the extension may define an implicit sphere, its `bounds` can limit the volume to be only half of the full sphere. @@ -137,5 +137,25 @@ The implicit **sphere** is centered at the origin in local space. The unit spher The implicit **ellipsoid** is centered at the origin in local space. The unit ellipsoid has radii of `[1, 1, 1]` along the `x`, `y`, and `z` axes. The `radii` property is used to scale the ellipsoid along these axes in meters. +**TODO** visual example + +``` +{ + "primitives": [ + { + "extensions": { + "EXT_implicit_geometry": { + "sphere": { + "radii": [2, 3, 4] + } + } + } + } + ] +} +``` + +### Region + ## Optional vs. Required This extension is required, meaning it should be placed in both the `extensionsUsed` list and `extensionsRequired` list.