Look at Controller Help

[Byteman]

I have assigned png images to plane objects and want them to look at the camera with the look at controller, but I want the planes to only rotate about the world z axis while looking towards the camera.

In other words I need to constraint the look at rotation only around the world z axis as in the image. Plane face looks at the camera but not towards it in height?

[domo.spaji · Accepted solution]

You can link those planes to some other helpers, dummies or whatever objects...

Look at constrain that helpers, dummies or whatever objects to camera...

For yours planes in Hierarchy panel - Link Info uncheck Inherit for Rotate X 'n Y

[Byteman · Accepted solution]

Thank you very much. It is a good solution. 

I've just learned that there is an MCG Look At Controller which is specifically for the purpose and does this thing in Billboard mode.