如何为Three.js中的属性分配常量值

Question

Basically what I am looking for is the Three.js equivalent to vertexAttrib . I intend to assign a constant value to my shader attribute.

Answer 1

You can do this by defining Material.defaultAttributeValues . It's an object where the key is the attribute name and the value is the constant attribute value. For example if you want to define a constant vertex color, you can do this:

var material = new THREE.MeshBasicMaterial( { vertexColors: THREE.VertexColors } );
material.defaultAttributeValues = {
    color: [ 0, 0, 1 ] // blue
};

When doing so, it's important to avoid a buffer attribute definition with the same name. Otherwise the geometry data are used and not the values from defaultAttributeValues .

Full demo

In any event, consider to use uniforms if a property is equal for all vertices. The better alternative for the above example is to define Material.color .

three.js R106