Need help with scale of 3D model

Questions
1

Hi,
I am new to three.js.
I use the gridhelper to draw a grid then I load a gltf model into this grid.
I add drag controls and I can drag my model. So far so good.
Trouble is when I move the model it stays at the same scale.
What I want to do is create the ‘illusion of depth’ that is, when I drag my model towards the ‘end of the grid’ down the back my model will become smaller and smaller.
Can you help?

2

What type of camera are you using? Consider to share your app as a live example or as a github repository.

3

I am using PerspectiveCamera
fov:75
near:1
far:1000

I already tried to change these values but that did not give me the desired result.

4

Any chances to share your code as a live example (https://jsfiddle.net/f2Lommf5/)? Sharing a github repository is also a good idea.

5

My app is using Meteor.js. Here is the code though you will not see the output:
https://jsfiddle.net/Menashay/96g5Lnox/9/

6

I think you are going to need to edit DragControls - see this:

instead of _camera.getWorldDirection( _plane.normal ) you want your grid normal

7

Thank you for your help.
I think TransformControls will do the trick.