Camera / model scale

does anyone know how to make a model auto scale to fit the camera

I don’t want the camera to zoom into the model

So you don’t want to transform the camera in any way? Or just not changing the zoom property? Zooming can also be achieved by moving the (perspective) camera closer to the model. This technique is called dollying.

I just don’t want to camera.lookAt(model) and just increase the the FOV . I just want to either move the camera closer or scale the object to the center of the camera

Can you resove it,i have same problem .

This is to dolly your camera at the right distance, in order to preserve the aspect of an object placed in world center …is this the problem, responsiveness?
But when you resize in portrait, if landscape should works by default

      camera.position.z = your_start_camera_distance/camera.aspect;
      camera.position.z= your_start_camera_distance;