Constraints

Hi everyone,



I’ve been trying to upgrade constraints loading from blender and I came accross one difficult problem.

When the animation is running some constraints are working well (not all of them are yet implemented).



But when constraints are applied to static scene there is no chance for them to appear until we run the object’s animation.



Would it be possible to create some ‘constraint system’ that would allow to add constraint to a node, spatial or bone and have it visible on the scene

even if the feature is not moving ??



I think it would be useful not only for blender importer but for the whole jme framework :slight_smile:



Tell me what do you think about it :slight_smile:

And tell me if such system exists (I may be unaware of it :wink: ).





Cheers,

Kaelthas

I dont really think it fits into jme. In a 3d editor you use constraints to edit animations, they make sure the movements you do with your mouse and keyframes look organic/real. In a game you just play animations or use physics or something similar to achieve this effect, there is no editing involved, hence animations should just be absolute, ‘baked’.

OK then,

so the solution would be to bake the constraint into the object if it has no animation.



The only difficulty would be with bone animations.

If a constraint is attached to the bone and the bone has a mesh attached to itself the mesh would be transformed.



Is there a simple way to calculate the mesh for a selected frame ?

Constraints work only on the bones no? I mean, just modifying the bone data should suffice, shouldn’t it?

I modify the bone tracks applying constraints to them.



But in blender you have also object animation and you can apply constraints to objects.

So applying constraints to objects should not be very hard.



It would be worse if somebody attaches object to a bone and adds a constraint to bone without animating it.

If I do not load the animation I cannot (or at least I do not know how :wink: ) apply the changes such constraint made.

I think I’ll focus on animations then and on static object’s constraints.



And how about the changes I suggested for animations??

http://hub.jmonkeyengine.org/groups/development-discussion-jme3/forum/topic/animations-in-jme/



It would really easy my life and I could easier implement full object-animation support.

I am ready to make such changes.

Just need your green light :wink:

A constraint system would be cool for the KinematicRagdollControl.

If constraints can be applied in real time according to physics interactions, that’s inverse Kinematic!



About the animation Change, go ahead, i’ll remove the rotation, scale, w/e tracks from the cinematic system.

But Kirill has some ideas for it too, so you should talk about it with him

I dont get it, whats the point? When you programmatically change values to a bone you can “constrain” yourself on that level, theres just no need to being able to enter values that are not applied (so you have to check each time after applying “did it work? or did I hit a constraint?”). Thats why I say constraints only make sense when you edit and are prone to “overdo” it with your mouse. Now physics constraints that @nehon mixes in here are a completely different topic ^^

oh uh… wait…so i don’t get it neither…What are the constraints you are talking about?