Screen xy to world coordinates

Questions
,
1

Hi,
apologize if looking in the forum I have already missed the answer to the question I’m about to ask

Someone can give me a concrete example of how to use Vector3 Unproject, to convert screen xy coordinates into world coordinates?

thank you in advance for any help!

2

Hey and welcome back!

here is how to use it:

        var vector= BABYLON.Vector3.Unproject(
                        mousePosition,
            	        engine.getRenderWidth(),
                        engine.getRenderHeight(),
                        BABYLON.Matrix.Identity(), scene.getViewMatrix(),
                        scene.getProjectionMatrix());
6 Likes
3

Thank you @Deltakosh!: )

the scenario is to set the position of a mesh.
Before I used the pickedPoint with this.scene.pick(this.scene.pointerX, this.scene.pointerY)

Does using Vector.Unproject way give the same results?

4

yep :slight_smile: mousePosition is your pointerX/Y thingy

2 Likes
5

Hi and thanks for a great product.

I would like to add - make sure your (input) mousePosition.z is set to 1 to get the expected results

I have been lurking for a while - writing a racing game … about 8 weeks in - thought I would try and make a positive contribution

5 Likes
6

Hey and welcome!!
Please share your game when you want :slight_smile:

7

Will do … although it is nowhere near as far along as the Need for Speed demo…

It’s a top down, racer with custom physics (mass spring system)… I am focussing on high frame rates and smooth gameplay, with analogue input (gyro, accelerometers, mouse) for a nice driving feel… cross platform obviously. I have one commercial game under my belt written with Direct X (QuickSnooker.com) but it is hamstrung by being PC only in an increasingly mobile world.

Lots to like about Babylon, have hit a few performance issues but nothing insurmountable, subdividing meshes should help, but that has broken picking at the moment, so I need to work out how to find the submesh from the subdivided mesh with ray picking … will ask more clearly if I get really stuck.

Very impressed by your dedication the the cause, I hope I can build something that does it justice.

Nick

8

Feel free! We are here to help

9

Hello everyone,

I am (I think) in the exact same issue. I need to add a sphere where the user clicks. I tried the following option :

var ballPos = BABYLON.Vector3.Unproject(
new BABYLON.Vector3(scene.pointerX,scene.pointerY,1),
engine.getRenderWidth(),
engine.getRenderHeight(),
BABYLON.Matrix.Identity(), scene.getViewMatrix(),
scene.getProjectionMatrix());

But the coordinates are really weird (like thousands or so)…

I thought about an option where I link a transparent plane end get the picked position but it’s seems a bit goofy.

Any idea ?

4 Likes
10

OK I think I have found the solution here : Scene.pointer to Vector3

3 Likes
11

Having same trouble here. Any help appreciated.

1 Like
12

is this one not working Scene.pointer to Vector3 - #2 by Cedric ?

13

Hi @trsh do you still have trouble?

16

The size of the result is related to the z-value of the source.Using a value smaller than 1 will get better results, or just normalize the result, then scaling to the size you want:

result.copyFrom(Vector3.Unproject(new Vector3(0,h*0.5,0),w,h,Matrix.Identity(),this._camera!.getViewMatrix(),this._camera!.getProjectionMatrix()));
const inv=this._camera!.getWorldMatrix().clone();
Vector3.TransformCoordinatesToRef(stw,inv.invert(),result);
result.normalize().scaleInPlace(10);
root.position.x=result.x;
root.position.y=result.y;
root.position.z=result.z;