Inverse Kinematics: Blender to Torque Animation

[Steve_Yorkshire]

Back in the heady days when I first downloaded TGE and Blender had an impenetrable interface - but hey, it was free and every other 3D modeling app cost a fortune - I had a look at using IKs and never quite got the hang of it. So 18 years later, I had another go, and finally, after much confusion, swearing and bourbon, I have finally managed to export an animation from Blender, import it into Torque, and miraculously have it work.

Now there are a lot more tutorials available in Space Year 2025 than there was back in Ye Olde Year Of Lord Anno Domini 2007. These tutorials always have the weapon pole using it's own armature with a handHigh, handLow, and central root bone. Once the character's hands have been IK'ed and parented to low/high bones, the pole itself is manipulated using the root bone and the hands follow in position.

Unfortunately there was still the minor issue of what looked good in Blender did not translate well to animating in Torque. 

Looks good right? Character hands aligned with the 2 big bones on the axe pole armature. Except ... narp ...

Now the problem here is that I had used IKs to attach the hand bones to the axe pole armature's own bones, handHigh and handLow. The axe armature itself is manipulated into place using a centralized root bone. Worked fine in Blender, but the angles were just slightly off in Torque. The selected axe shown in Blender is connected directly to mount0, which is not a connected bone though it is a child of the hand bone. I played around with a few variations, but could never get the translation correct when importing into the engine. I tried attaching the IKs via the mountPoints directly, but with them being non-connected they moved all over the place which looked horrible in Blender, even if the pole stayed in the character's hands.

So, the obvious solution seemed to be to parent the axe pole model MESH to the character armature in Blender, specifically to the hand bone, making sure that the tip of the hand bone was positioned to the center of the mountPoint tail/origin sphere in the Z axis. Whilst Blender likes using tips of bones, Torque likes using the tail/origin (or is it the other way around? ). The axe pole armature is now devoid of a mesh, but still needs to brought into play because the left hand needs to attach to the lower hand placement bone. When manipulating the characters right hand bone (with the axe mesh parented to it), the axe pole's armature bone of root must be moved TOGETHER, thus keeping the left hand at the handLow bone position on the pole. See why I always found this complicated?

The original armature above, and the new armature below (including IK constraints).

Now I was a little reticent about shifting my armature bones around, but because all my previous animations don't use IKs, and the mountPoints are not connected, this change does not affect or distort all my previous animations ... which is nice. This was just a quick test and there is a bit of unsightly twisting in the left upper arm, but all that can be smoothed out by rotating the bone locally through it's own central axis.

Having to keep selecting the pole armature's root bone when moving the character's hand bone is a bit of a kerfuffle, so here is a slightly easier way; take the axe pole armature's root bone, and parent that to the character armature's mount0 using IKs. Then use IK copy location, and copy rotation to keep the axe pole exactly following the character's hand movements. Now you can just hide the axe pole armature in the inspector so you don't have to see it anymore.

So now with the axe pole mounted to the armature and correctly positioned as it would be in-game, only the left/supporting hand bone needs to be IK'ed into position to keep it stable during the animation.

The character's armature's left hand bone IK is set to the axe pole armature's hadnLow bone, where I want the character's left hand to hold, and the left hand bone is set to child of axe pole armature's root bone. When you want to move the axe model, which is now just a mesh attached to the player's right hand, you need to select both the player's hand bone and the axe pole's root bone.

I chose an IK chain of 3 which leaves the shoulder bone alone, and you probably want to stay the hell away from having any of this affect the spine bones or else your character is going to look like a body popping champion (which was a thing in the heyday of Gen-X ... before the Dark Times Of The Great Shadow Fell Upon This Land ...)

After re-exporting the character with the new bone arrangements, and exporting the animation as it's own DAE file (because I haven't got round to converting everything to a more modern FBX yet) - et voila! It's in the engine and working as God and nature intended.

So yeah, that only took 18 years to get it to work. 

Edited August 28 by Steve_Yorkshire
Lack of clarity in setting up the axe pole armature

[fLUnKnhaXYU]

thank you Steve  . its so cool . you must feel ver powerful . super congrats !