# Orient an object relative to another and constrain distance to radius

I've got two objects: a cylinder and a cone. I want the cylinder to effectively act as a constraint on the cone such that the cone is always the same distance from the cylinder and the cone is always oriented away from the center of teh cone such that the tip of the cone would be touching the cylinder, regardless of where it is moved / rotated. The two objects don't actually have to be constrained to each other, I just need the illusion of constraint. In other words, if we could accomplish the same effect on the cone without having the cylinder actually exist, that would work as well.

How can I accomplish this?

• Sounds like you could do this mostly with two constraints Limit Distance and Locked Track – Duarte Farrajota Ramos Oct 12 '18 at 3:37
• "...the same effect on the cone without having the cylinder actually exist" and "the tip of the cone would [always] be touching the cylinder" these two constraints would mean that the cone will always move in a circle with the tip pointing towards the center of that circle, which tit orbits. Is that the requirement? – Blender Dadaist Oct 12 '18 at 4:46

Objective - Make a cone follow (track) a cylinder's location whilst maintaining a constant distance from it. (as distinct from straight out parenting)

A script would be the elegant way to do this but for a quick handcrank job, read on...

The cylinder is the parent of an invisible (green) plane. The plane's pivot point has been set to one of it's ends so it will always pivot out from the cylinder's center. It's far end will be a constant distance from the cylinder's center.

The plane is parented to a vertex placed at the cylinder's center.

This prevents the plane from rotating topsy turvy as the cylinder does but will follow changes in it's location.

The cone is parented to the plane and positioned at it's far end. It is also rotated to be looking back along the plane's axis and always pointing at the cylinder's center.

An empty has been placed somewhere central to and above the cylinder's anticipated motion. (along a path in this instance)

The plane is then given a constraint to "Track to" (look at) the Empty.

The empty can be moved about to vary the cone's orientation.