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So I'm planning a new portfolio piece, and for it to turn out how I want, I need some help with constraints. There is going to be a star that always faces the camera, and that much I figured out. The problem is I want the star to always be right side up from the cameras POV, so I think there needs to be an additional rotation constraint as well. I don't know how to go about it though. Advice?

Michael
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  • What is your setup like? Have you parented the camera to the star? This will both make the object always face the camera, as well as move with it (including rotation). – Christopher Bennett Jun 24 '20 at 02:34
  • Are you trying to lock cam to object and limit rotation to single axis of object at same time? – Timaroberts Jun 24 '20 at 02:54
  • Hi Christopher, I tried parenting the camera to the star, but it wasn't quite what I was looking for. More or less, I just want the star to orient itself to appear right side up in the camera's view, no matter what position the camera is in.

    And Timaroberts, I think that might be what I'm looking to do. How would I go about setting that up?

     – Michael Jun 24 '20 at 03:45

3 Answers3

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Locked Track Constraint

enter image description here

Locked Track Constraint

Setup Suzanne akin to a compass needle via the locked track constraint. Suzanne faces the camera (To -Y) and can only rotate on the Z axis (Lock)

batFINGER
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One way to do this is with constraints. Namely the damped track and limit rotation constraints.

Here is how to do it:

First select your object and add a constraint, choose damped tracked from the drop down. In many cases, the axis will be -Z and in this case, our target will be the camera object. enter image description here

Next, add a limit rotation, and tick both axes you wish to lock or limit. Here, I have ticked the X and Y axes thus disabling them, permitting the star to only rotate around the Z axis as it tracks the camera. This of course can be arranged however you need for your specific scene.

enter image description here

This is the result:

enter image description here

Timaroberts
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If I understand correctly, you want your star to behave as a "billboard". There are lots of tutorials out there, one for example here: https://www.blendernation.com/2019/04/27/how-to-properly-billboard-sprites-particles-in-blender/

This tutorial shows essentially the method also described by @batFINGER, using the "locked track"-constraint.

haarigertroll
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  • Imagine this is the track to constraint... could you please flesh this out in answer. Link only answers often get removed in review. – batFINGER Jun 24 '20 at 05:54
  • My answer is essentially a link to a tutorial describing the method you also posted as your answer with the "locked track" constraint. Mainly I wanted to bring up the "billboard"-keyword, so OP has a better lead for searching further instructions. – haarigertroll Jun 24 '20 at 07:02
  • Thanks for the help everyone! Ultimately, it wound up being a combination of Tima and Batfinger's solutions. I applied both to the star. I also added a track to constraint on the camera, targeting an empty that was a child of the star It turned out beautifully! Thank you both! – Michael Jun 24 '20 at 07:29
  • @haarigertroll Ok,I need to look it up too lol, assumed it was the full monty track to – batFINGER Jun 24 '20 at 09:39