void checkDoTransformUpdate() {
        if ((refreshFlags & RF_TRANSFORM) == 0) {
            return;
        }

        if (parent == null) {
            worldTransform.set(localTransform);
            refreshFlags &= ~RF_TRANSFORM;
        } else {
            TempVars vars = TempVars.get();

            Spatial[] stack = vars.spatialStack;
            Spatial rootNode = this;
            int i = 0;
            while (true) {
                Spatial hisParent = rootNode.parent;
                if (hisParent == null) {
                    rootNode.worldTransform.set(rootNode.localTransform);
                    rootNode.refreshFlags &= ~RF_TRANSFORM;
                    i--;
                    break;
                }

                stack[i] = rootNode;

                if ((hisParent.refreshFlags & RF_TRANSFORM) == 0) {
                    break;
                }

                rootNode = hisParent;
                i++;
            }

            vars.release();

            for (int j = i; j >= 0; j--) {
                rootNode = stack[j];
                //rootNode.worldTransform.set(rootNode.localTransform);
                //rootNode.worldTransform.combineWithParent(rootNode.parent.worldTransform);
                //rootNode.refreshFlags &= ~RF_TRANSFORM;
                rootNode.updateWorldTransforms();
            }
        }
    }
Computes the world transform of this Spatial in the most
efficient manner possible.
jme3-core/src/main/java/com/jme3/scene/Spatial.java