How to rotate mesh with ArcCamera's alpha?

[kevzettler]

I have an ArcCamera with a root object as it's target. I'm going for a 3rd person or "over the shoulder camera". I want the root to rotate on the y axis when the ArcCamera moves on the alpha axis. I'm currently doing something like:

Quote

root.rotation.y =  -1 * camera.alpha;

It seems like the alpha is at a lower magnitude than what the rotation vector expects. I can rotate the camera like 3 times around the root before it rotates completely 

[Temechon]

Hey, 

I'm not sure if I can help, but did you take a look at ArcFollowCamera ? http://doc.babylonjs.com/classes/2.5/arcfollowcamera

[kevzettler]

I have looked at ArcFollowCamera it dosen't seem to be working for though. Once attached to a target to follow I cannot control it. I setup a playground here http://www.babylonjs-playground.com/#4FC2X#0

Also to get the desired effect I want, I would still have to rotate the target mesh based on the ArcFollowCameras alpha.

[GameMonetize]

Hello using the ArcRotateCamera should work but as you already found out, the camera.alpha is an angular rotation (based on a radius). 

To help you , can you provide a PG with your initial setup? (With the arcrotatecamera and the mesh)

[kevzettler]

@Deltakosh I'm having a hard time reproducing my setup in the playground environment. Playground is using v2.6-alpha I'm not on the same version. Actually I'm not sure what version I'm using is there a value I can check? Even so seems like coordinates are different between the two environments.

Here's my best attempt at reproducing http://www.babylonjs-playground.com/#GVPCK#4

Here's a better example on my production environment http://localhost:8000/robotbones/attempts/babylon/babylon-bones-qubicle-CEWBS/

Essentially I want the character to face the direction the camera is facing on rotate. I thought I could maybe use the alpha from the rotateCamera but maybe I can take the a direction vector from the character to traget and apply that to the character instead.



 

[GameMonetize]

Hello, you can check engine.Version to get your version

 

You can also think about using some code from camera.getFrontPosition: https://github.com/BabylonJS/Babylon.js/blob/master/src/Cameras/babylon.targetCamera.ts

 

[kevzettler]

thanks @Deltakosh

I was able to get the effect I want by doing

focus = arcCamera.getFrontPosition(100);
focus.y = 0;
focus.multiplyInPlace(negativeVector);
mesh.lookAt(focus);

How do I move the camera towards that direction? I'm currently moving the mesh with mesh.translate when keys are down. I want to do the same movement with the camera. Seeing the camera dosen't have a translate method

[GameMonetize]

You have to just call arcCamera.setPosition(newPosition);