Camera InterestPosition

[Anonymous]

Hi,

I have a couple of questions about the camera InterestPosition property.

Should InterestPosition only be used if the ViewCameraToLookAt property is true?

Does InterestPosition override rotation from the camera node's LclRotation? I assume it would.

Regards,

Jo

[RobertGoulet]

If LclRotation has animation, InterestPosition will never be considered. In fact, to correctly evaluate the LookAtPosition, the FBX SDK first checks if there's a Target object on the node, then LclRotation, and then use InterestPosition if all fails. InterestPosition shall not be animated.

[Anonymous]

Thanks Robert. What happens if LclRotation is not animated though?

One scenario I can see in that situation is that I would look at ViewCameraToLookAt and if that was true then I would use the InterestPosition to set the orientation. If it was false I would use LclRotation. Is that a correct interpretation?

Regards,

Jo

[RobertGoulet]

The property InterestPosition value can only be considered if there's no Target object connected to the node, and if there's no animation on LclRotation. It's really just a last fallback in case everything else failed.

[Anonymous]

Hi Robert,

Sorry to be a nuisance, but I want to make sure my importer is doing the right thing with cameras. I understand about the Target object and animated LclRotation. Let's say I have a camera node set up like this:

- It doesn't have a Target object.
- LclRotation is not animated.

How do I know if I should be considering the InterestPosition in this situation? Should I be checking the ViewCameraToLookAt property to see if it's true? Should I be checking InterestPosition.IsValid() ?

Does the InterestPosition override the LclRotation of the camera? You say it's a last fallback but it looks like to me that for a non-Target/non-animation-rotated camera there are still two factors in play here. There is the InterestPosition and there is the non-animated LclRotation value. My guess is that the InterestPosition would override the LclRotation but it's only a guess on my part.

Here's what I'm guessing the order of precedence for finding the camera orientation would be, with Target object being the first factor considered:

Target object
LclRotation with animation
InterestPosition
LclRotation

I had a look at the MotionBuilder docs but it didn't really clarify anything for me.

Thanks for your help.

Regards,

Jo

[RobertGoulet]

1. Target Object
2. Animated LclRotation
3. Interest Position