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...