Resizing uploaded .obj file in 3D scene

Questions
1

I have .obj file being loaded using
let objLoader: OBJLoader = new OBJLoader();

  objLoader.load(

    'assets/device.obj',

    (object) => {}

)

perspective camera is being made use of and positioning and rotating also happens to uploaded object(THREE.Object3D)

How can i resize the uploaded object to real world 0.27m width regardless of positioning and rotating.

2

Let size = Box3.setFromObject( yourobject ).getSize(nee THREE.Vector3())

Gets you the size of the object… Then you can yourObject.scale.multiplyScalar(.2/size.x)

2 Likes
3

I already tried this, it works perfectly for the first time when camera obj is loaded, drawCamera() gets called if riverCamY or riverCamX or riverCamZ value changes. Here please note that X is mapped to Y, Y is mapped to Z, Z is mapped to X
When riverCamX value is changing, camera3DObject size is same but visually it is appearing small and larger, maybe because each time positioning and rotation also changes, now how can I keep camera3DObject visually also same

private drawCamera(): void {

let riverCamY = parseFloat(this.analysisSettingsModel.analysisCameraPositionY?.toString() || "0");

let riverCamX = parseFloat(this.analysisSettingsModel.analysisCameraPositionX?.toString() || "0");

let riverCamZ = parseFloat(this.analysisSettingsModel.analysisCameraPositionZ?.toString() || "0")

let riverCamVisibility = this.analysisSettingsModel.cameraVisible;

const riverCamMeshName = "riverCam_mesh";



if (riverCamVisibility) {

  this.camera3DObject.name = riverCamMeshName;

  const verticalCrossSectionCenter: number = this.bottom.y;

  const diffBetweenCenterAndCamY = Math.abs(verticalCrossSectionCenter - riverCamZ);

  this.camera3DObject.position.set(riverCamY, (verticalCrossSectionCenter + diffBetweenCenterAndCamY), -Math.abs(this.bank1?.x - this.bank2?.x) / 2 + riverCamX);

  this.camera3DObject.position.z += 0.5;

  this.riverCamObject = this.camera3DObject;

  if (!this.isValidOBJ(this.camera3DObject)) {

    let objLoader: OBJLoader = new OBJLoader();

    objLoader.load(

      'assets/camera.obj',

      (object) => {

        object.name = this.camera3DObject.name;

        const verticalCrossSectionCenter: number = this.bottom.y;

        const diffBetweenCenterAndCamY = Math.abs(verticalCrossSectionCenter - riverCamZ);

        object.position.set(riverCamY, (verticalCrossSectionCenter + diffBetweenCenterAndCamY), -Math.abs(this.bank1?.x - this.bank2?.x) / 2 + riverCamX);


        object.scale.setScalar(0.001); // converts mm → meters

        // Ensure the transformation is applied

object.updateMatrixWorld(true);

        this.changeCameraFacing(object);

        object.traverse((child) => {

          if (child instanceof THREE.Mesh) {

            // Change the material color to the specified color

            child.material.color.set(0x404040);

            child.geometry.computeBoundingBox();

          }

        });

        if (this.savedRotation) {

          object.rotation.copy(this.savedRotation);

        }

        this.camera3DObject = object;

        this.camera3DObject.position.z += 0.5;

        this.addOrReplaceToSceneByName(riverCamVisibility, riverCamMeshName, object);

        return;

      },

      (xhr) => {

      },

      (error) => {

        console.error('Error loading OBJ:', error);

      }

    );

  }

}

if (this.savedRotation) {

  this.camera3DObject.rotation.copy(this.savedRotation);

}

this.changeCameraFacing(this.camera3DObject);

this.addOrReplaceToSceneByName(riverCamVisibility, riverCamMeshName, this.camera3DObject);

}