Where is the spherical geometry button?

[Pitcher]

Recently, I had occasion to be moving models on a sphere. To be more precise, I was moving ships on a globe to show travels. Well, guess what? The program moves models from point A to point B in a straight line. The ships kept submerging. Unless I put the ships well above the water, I have to change their location (z as well as x and y) very frequently as they move along the timeline. If I put them well above the water, the angle of view sometimes makes them look like they are very far from where I wanted them to be. Sometimes they look like they are on the land. This becomes an issue especially as they are approaching a port. Does anyone have any ideas? Is there a spherical geometry button that allows us convert to sperical geometry and insert the circumference of a sphere for the computer to automatically calculate the in-betweens using spherical geometry? I don't know much about any of this, but I thought someone else might.

 

It could be used for a mosquito or fly to roam across a person's nose or some other sphere. There are probably many uses I will never think of.

[robcat2075]

One solution would be to constrain a ship to a bone that is at the center of the sphere, then animates the bone to move the ship on the surface of the sphere.

 

You would use both a Translate and Rotate constraint in this case.

[robcat2075]

There is also a "Surface" constraint that can track an irregular surface. That setup is slightly more involved.

There is a tut on Surface constraint in post #4 here...

 

http://www.hash.com/forums/index.php?showtopic=45641&p=391354

[Pitcher]

That's a great idea, robcat 2075. I think that would probably work. Thanks for the idea! It occurs to me that this question resulted from my trying to animate by moving something from point to point until I reached a destination. I became locked into that way of thinking. I kept putting more in-betweens to see if that would fix the problem. It didn't. After I posted this, I sat down and relaxed waiting for an answer, and it occurred to me that I should just make a path for each ship and constrain each ship to its path. Paths often go in a circular way. I should have gotten away from the problem for a bit.

[Pitcher]

I did the paths for each of the ships. Everything looks fine from the Front View, but when I render, they still go underwater. I've decided this happens because rendering does some sort of smoothing to the globe and makes it slightly larger. The result is that the ships go underwater. I hate to think there is something that cannot be done, but maybe this is it.

[robcat2075]

I'd have to see more to know more, but I'm confident it can be done.

[Pitcher]

I had to see more too. What I was going on was the frame by frame it does as it renders. There the ships went underwater. When I actually viewed the video, however, the ships were afloat. You are right. It can be done.