How to Set Plane Mesh to always lookAt camera without tilting

Question

I'm trying to make a Plane to always face the camera or another moving object but I want the Plane to only rotate on 1 axis. How can I use the lookAt function to make it only rotate side ways without tilting to look up or down at the moving object?

maybe put the camera and the plane under the same node in the scene graph? http://jsfiddle.net/dmt23/yqkmpe5t/ — mdan, Nov 03 '14 at 16:28

score 1 · Answer 1 · answered Nov 04 '14 at 12:00

1

thanks, I managed to solve it easily by just keeping the y position of the rotating object constant.

if(planex){
    var yaw_control = controls.getYawObject();
    pos = new THREE.Vector3( yaw_control.position.x, planex.position.y, yaw_control.position.z );
    planex.lookAt(pos);
}

answered Nov 04 '14 at 12:00

user3661557

138
12

2

Don't use `new`. Create one `pos` vector and reuse it: `pos.set( x, y, z )`. – WestLangley Nov 04 '14 at 16:08

score 0 · Answer 2 · edited May 23 '17 at 12:13

http://www.lighthouse3d.com/opengl/billboarding/index.php?billCyl

maybe this article of any help for you. You are looking for those cylindrical billboards i think but read up from the first page ;) You can modify the specific mesh matrix yourself, although i am not sure if this is the most efficient way. I also did this myself once.

Get the camera look vec:

three.js set and read camera look vector

Then get the camera upVec and afterwards get the cross prodcut of those = rightVec according to the article above.

using those vectors, you can fill in a new Three.Matrix4() like explained in the article and then replace the meshes matrix with the newly created one. As I said, i am not quite into the matrix stuff in three.js but this works but it is probably not that efficient.

For this to work you will have to deactive the meshes auto matrix update with

mesh.matrixAutoUpdate = false;

How to Set Plane Mesh to always lookAt camera without tilting

2 Answers2