Select a mesh and change it's color?

[maxime1992]

Hi! 

I'm completely a newbie in 3D world and BabylonJs.

What I'd like to do is to be able to select a given mesh by clicking on it and change it's color to show that it has been selected.


I've created a really basic scene with 2 meshes and googled my problem but couldn't find anything about that.
Maybe it's super trivial (?)

Here's my example, thanks for any help or any useful resource to get started on this task

https://playground.babylonjs.com/#TC2K69

[aWeirdo]

Hi @maxime1992
Welcome to the forums.

Pretty simple task; https://playground.babylonjs.com/#TC2K69#1

You can read more about picking here; http://doc.babylonjs.com/babylon101/picking_collisions

[maxime1992]

Hey, thanks for the quick answer (and the demo!) @aWeirdo 

I'm facing 1 issue though with your demo:

It's selecting or loosing the focus on a mesh if I drag and drop in/out of one of them.
For example the biggest part is selected, you just want to rotate the camera and drag from/to an empty point, you'll lose the focus.

I thought of using 

scene.onPointerPick

But I'm getting scene.onPointerPick is not a function

I tried to search into the event but there does not seem to be a starting and ending position so I don't know how to figure out whether it's a drag or not

[babbleon]

try this with line #36 commented out.:

https://playground.babylonjs.com/#TC2K69#3

 

[aWeirdo]

Hi again @maxime1992 
I added the following code to allow de-selecting 

if(selected) {
  selected.material.diffuseColor = BABYLON.Color3.White();
  selected = null;
}

You can move it inside the hit-test to only allow de-selecting when selecting a new mesh,

if(evt.pickInfo.hit && evt.pickInfo.pickedMesh && evt.event.button === 0){
  if(selected) {
    selected.material.diffuseColor = BABYLON.Color3.White();
  }
  selected = evt.pickInfo.pickedMesh;
  evt.pickInfo.pickedMesh.material.diffuseColor = BABYLON.Color3.Green();
}

Or you can check if the pointer moves between pointerdown & pointerup
(this will however make it difficult/impossible to pick if the pointer moves even slightly)
https://playground.babylonjs.com/#TC2K69#4

You can also create pointerCaches and check how much a pointer has moved between pointerDown and pointerUp,
Avoids a million pointerMove fires, and lets you set a limit for how much a pointer is allowed to move and still fire the de-/select code
https://playground.babylonjs.com/#TC2K69#5

 

[maxime1992]

@babbleon tried but it's not working as expected 

@aWeirdo thx it's getting closer

BUT, if you make the scene rotating with your mouse and while it's rotating/in motion, click on a part it'll not be selected/unselected.

[maxime1992]

=x my bad @aWeirdo !!!

It's perfect, thanks for your help