Compute Boundingbox from a group of Objects

compute_boundingbox_group_objects.js

                    
    /**
     * Calculates the bounding box of grouped 3d Objects, with Objects that contains geometries
     * @param {Object3d} objectgroup A Object3d that contains other Object3d objects like Mesh.
     * @return {Object} Returns a Object with two parameter min{THREE.Vector3} and max{THREE.Vector3}
     */
    function computeBoundingBoxGroupObjects(objectgroup){
        var minX = 0, minY = 0, minZ = 0, maxX = 0, maxY = 0, maxZ = 0;
        function getBox(item){
            if(item.geometry){
                item.geometry.computeBoundingBox();
                minX = Math.min(minX,item.geometry.boundingBox.min.x);
                maxX = Math.max(maxX,item.geometry.boundingBox.max.x);
                minY = Math.min(minY,item.geometry.boundingBox.min.y);
                maxY = Math.max(maxY,item.geometry.boundingBox.max.y);
                minZ = Math.min(minZ,item.geometry.boundingBox.min.z);
                maxZ = Math.max(maxZ,item.geometry.boundingBox.max.z);
            }
        }
        if( objectgroup instanceof THREE.Object3D){
            objectgroup.traverse(function(_item){
                getBox(_item);
            });
        }
        if( typeof objectgroup === 'object' && typeof objectgroup.slice === 'function'){
            for(var i = 0; i < objectgroup.length; i++){
                getBox(objectgroup[i]);
            }
        }
        return {
            min: new THREE.Vector3(minX, minY, minZ),
            max: new THREE.Vector3(maxX, maxY, maxZ)
        };
    };