Informing Three.js about updates

If you've worked a bit longer with Three.js, you'll probably have noticed that sometimes, it seems that changes you make to a certain geometry doesn't always result in a change onscreen. This is because for performance reasons, Three.js caches some objects (such as the vertices and faces of a geometry) and doesn't automatically detect updates. For these kinds of changes, you'll have to explicitly inform Three.js that something has changed. In this recipe, we'll show you what properties of a geometry are cached and require explicit notification to Three.js to be updated. These properties are:

• geometry.vertices

• geometry.faces

• geometry.morphTargets

• geometry.faceVertexUvs

• geometry.faces[i].normal and geometry.vertices[i].normal

• geometry.faces[i].color and geometry.vertices[i].color

• geometry.vertices[i].tangent

• geometry.lineDistances

Getting ready

An example is available that allows you to change two properties that require an explicit update: face colors...