P3D v4 Blender export constraints


Resource contributor
Hi all!

I am quite sure someone must have discussed this at some point before, but I cannot figure it out at the moment.
I'm trying to export a "copy rotation" constraint. The setup includes the front gear door and an empty object. So the door has a local Y-axis that I want to rotate it on (i.e. I do not want it to rotate on any other axis) and I constrainted it to the empty, which then is animated to rotate on the global Y-axis, so as to force a rotation on the local Y-axis of the door object. So far so good, but this does not export in to MDL, ofcourse perhaps, but is it at all possible to get this done?

Otavio Bonomi

Resource contributor
You have a point here,
maybe if you open the 3d file in gmax and work in the animation manager,
I'm having a problem with my hangar animated for SODE, where I opened it in Gmax (I do not have much experience with Gmax) and I can not save the animation.
I'm looking for more information and if I find I'll tell you, sorry.


Resource contributor
I know almost nothing about Blender but I do know about animation constraints in Gmax and 3ds Max and they don’t export to FS. I fully expect you’ll have to reduce the constrained animation to keyframes.


Resource contributor
Yeah I was afraid of that. So in that case I have two options I guess.... Either I find a way of getting the rotation on just the local axis (and no other axis then that axis) or I let it keyframe the whole thing...


Resource contributor
Keep It Simple Frits my advice, Do not add any more then you have to, in a Blender to FSX/P3D export, since opening and closing doors can be done without it:
Here is an example how it can be done
1. Create an empty which is perfectly aligned with the pivotpoint hinge of your front-gear-door.
2. Cut of the Front-gear-door-area from the front fuselage section.
3. Now parent the front-gear-door to the relevant empty.
4. Set the origin-point of the front-gear-door to the relevant empty axis and you are ready
5. You now can create the "open-and-close" animation of the front-gear-door by simply rotating the (hinge) empty over the right x,y,z-axis
It is as simple as that.

If you want a video to go with this explanation, watch the famous Krispy1001 Blender2FSX - V22 "landing gear animation" video on Youtube:


Resource contributor
Thanks for the input Ronald. However I'm looking to rate these doors on axis that do not fit the global axes. I'm sure other people will have had to face similar issues though...
Hello F747fly,

My constraints are exported normally from Blender, without any problem. But if I understand correctly, in your case, you have an empty object that moves on any axis, and you just want your door to follow it...? All you have to do is create a parent link between your door and your empty object...


Resource contributor
That's right Chris, to illustrate the issue I've captured a video recording of it:

As you can see the one side (right-hand) is animated with the constraint so that it moves in a, for humans, logical way along a single local axis (local Y). However the other side (left-hand side of the plane) is animated as one normally would and ask you can see Blender does the most logical thing for a computer, it finds the shortest route through x and y. So I want it to be like the right-hand side, but the constraint I am using doesn't seem to export...
But when you say that the constraint is not exported, you mean that there is no animation at all...? Or, there is an animation, but not the one desired by the constraint...?

For each side, you have an empty object... This empty object must be placed and animated exactly in the axis of rotation you want (for opening every door). Then, the door will become the child of your empty object, and the export of the animation will be done without any problem...! But there must be no mirrors or other parents.

In the worst case, you can send me your model so I can check...!
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