Problem following motion path

[Anonymous]

I wonder if somebody could help me please. I’ve got a vehicle that I want to travel around a sphere. I’ve created a motion path round the sphere but when the vehicle follows the path it flips and rotates all over the place. I’ve tried changing the from axis and up axis as well as checking and unchecking the follow box but nothing seems to help it follow the path normally all the way. I don’t really want to have to adjust it manually so didn’t know if there’s was anything I could do to make it follow the path properly/realistically?

Thanks in advance for any help.

[tdHendrix]

Not sure if this will help in your case, but you can try the technique from this video:

https://www.youtube.com/watch?v=05suBsDZ4ZE

It helped solve my flipping issues before.

[Anonymous]

Thanks for that but unfortunately it didn’t help as my path goes in all three axis. My path is projected onto a Nurbz sphere in all directions

[mspeer]

Hi!

Just don't use Follow (Vector) from your Motion path , cause you don't have a constant up-vector, instead use Contrain ->  Aim for the orientation of the car (use the sphere or an other object at sphere center as aim target).

[Anonymous]

Sorry to ask a really dumb question but how do I actually do that? Particularly the part about setting the aim for the orientation of the car?

[mspeer]

Hi!

Ok, one step back.

The Motion Path already has an option to orient to the origin of an object.

1. Enable Follow and as World Up Type use "Object Up"

2. As World Up Object enter the name of the object (transform node) you want to orient too (like your sphere or simply a locator).

Just make sure all axes definitions are set right.

[Anonymous]

Unfortunately that didn't work either 😞 Do I need to go to Constrain > Aim after?

[mspeer]

Hi!

What does this mean: "that didn't work" ?

Error message, nothing changes,...?

Please upload your scene-file.

[Anonymous]

Nothing changed at all, it still kept changing direction and rotating. 😞

Thanks for helping with this, I've attached the model

[mspeer]

Hi!

In your scene there is no motion path applied.

But i found your problem. Select one bus choose Move Tool and set Axis Orientation to Object.

That's your problem these axes are used for orientation but they are not aligned with the bus.

Modify your pivot and then bake pivot, with proper orientation it will work fine.

[Anonymous]

Thank you, I'll try that. One thing I didn't understand though was you said moving then baking the pivot - I didn't understand about baking it?

[mspeer]

Hi!

By default the rotation settings for the pivot will only be used for the current action and will not be stored after editing, so you need to "bake" it.

[Anonymous]

Okay now this is going to be a dumb question - how do I actually bake it?

[mspeer]

Hi!

1. Selecting Move or Rotation Tool

2. Hit hotkey "D" or "Insert" to change to Pivot Mode

3. Modify the Pivot

4. Modify -> Bake Pivot

Please read the Maya Online Help / Documentation for more details.