/**
 * Struct for representing the output of a custom vertex shader.
 * 
 * @name czm_modelVertexOutput
 * @glslStruct
 *
 * @see {@link CustomShader}
 * @see {@link Model}
 *
 * @property {vec3} positionMC The position of the vertex in model coordinates
 * @property {float} pointSize A custom value for gl_PointSize. This is only used for point primitives. 
 */
struct czm_modelVertexOutput {
  vec3 positionMC;
  float pointSize;
};