Method renderTarget

src/OldSparkViewpoint.ts:328–365

({
    scene,
    camera,
  }: { scene: THREE.Scene; camera?: THREE.Camera })

  // Swaps buffers if doubleBuffer: true was set.
  // Calls onTextureUpdated(texture) with the resulting texture.
  renderTarget({
    scene,
    camera,
  }: { scene: THREE.Scene; camera?: THREE.Camera }) {
    const target = this.back ?? this.target;
    if (!target) {
      throw new Error("Must initialize SparkViewpoint with target");
    }

    camera = camera ?? this.camera;
    if (!camera) {
      throw new Error("Must provide camera");
    }
    if (camera instanceof THREE.PerspectiveCamera) {
      const newCam = new THREE.PerspectiveCamera().copy(camera, false);
      newCam.aspect = target.width / target.height;
      newCam.updateProjectionMatrix();
      camera = newCam;
    }
    this.viewToWorld = camera.matrixWorld.clone();

    const previousTarget = this.spark.renderer.getRenderTarget();
    try {
      this.spark.renderer.setRenderTarget(target);
      this.spark.prepareViewpoint(this);

      this.spark.renderer.render(scene, camera);
    } finally {
      this.spark.prepareViewpoint(this.spark.defaultView);
      this.spark.renderer.setRenderTarget(previousTarget);
    }

    if (target !== this.target) {
      // Swap back buffer and target
      [this.target, this.back] = [this.back, this.target];
    }
    this.onTextureUpdated?.(target.texture);
  }

  // Read back the previously rendered target image as a Uint8Array of packed
  // RGBA values (in that order). If superXY was set greater than 1 then