Need help, best practice of useFrame animation driven by controller

[hainesc]

I am a newbie here. I am working on a machine tool model for a week, I have made it in blender and import to my project by gltfjsx. Also together I have a controller which read data from backend, it's action data, such as rotate left leg bone at speed 5. I use those data to drive my model to make animation.

For simple I used robot model as example here.
https://threejs.org/examples/#webgl_animation_skinning_morph

After gltfjsx parsed, I insert

  const action = useControls();  // this is my controller, in this example we can just generate some random actions every 1 second
  useFrame(() => {
    // get left leg and right leg
    let leftLeg = nodes.Bone.children[1]?.children[2]; 
    let rightLeg = nodes.Bone.children[1]?.children[3];
    // animation the model by the action data here
    if (action?.segment == "left leg") { 
      leftleg.rotateX(action.speed);
    } else if (action?.segment == "right leg") {
      rightleg.rotateZ(action.speed);
    }
  });

It works but I found the whole Robot component re-render every 1 second(same as the interval that controller updates the action). In my real project the data change more frequently so I do not want re-render the model. I have changed
const actionGetter = useControls(); and made my controller return a getter function but it did not prevent the re-render.
I have also tried leva useControls yet but nothing good.

So my question is: what's the best practice to drive the model by controller and don't re-render the heavy model when the data changes?

[hainesc]

https://r3f.docs.pmnd.rs/advanced/pitfalls there are many suggestions here.

[hainesc]

Using forward ref here

 npx gltfjsx -t ./public/robot.gltf

Then modify the line
export function Model(props: JSX.IntrinsicElements["group"]) {

to

export const Robot = forwardRef<
  JSX.IntrinsicElements["group"],
  React.RefObject<HTMLSelectElement>
>((props, bones) => {

And find the line

<primitive object={nodes.Bone} />

and then add ref={bones}

<primitive ref={bones} object={nodes.Bone} />

Make a new tsx file named RandomControlledRobot.tsx

  const [action, setAction] = React.useState<Action>(null!);
  useEffect(() => {
    const generateRandomAction = async () => {
      let random = Math.floor(Math.random() * 4);
      let action = {
        segment: segmentMap.get(random) || "left hand",
        action: XYZMap.get(random) || "X",
      };

      setAction(action);
    };
    const interval = setInterval(() => {
      generateRandomAction();
    }, 5000);

    return () => {
      clearInterval(interval);
    };
  });

  const bones = useRef();
  useFrame(() => {
    let leftLeg = bones.current.children[1]?.children[2];
    let rightLeg = bones.current.children[1]?.children[3];
    if (action?.segment == "left leg") {
      leftLeg.rotateX(0.01);
    } else if (action?.segment == "right leg") {
      rightLeg.rotateZ(0.01);
    }
  });

  let robot = useMemo(() => {
    return <Robot props={props} ref={bones} />;
  }, []);
  return robot;