Bone scaling and translating in the world

[manuel.gysin]

Hello

 

 

Maybe it's only a simply problem but I can't find a solution since days:

 

 

Situation:

I load an ObjectMeshSkinned (Human character) and scale a bone.

The feet of the object are on the ground.

 

character.setFrameBoneTransform(character.findBone("Bip01"), initialTransformValues[_boneType] + scale(0, 0, newValue));

 

This works fine and the whole ObjectMeshSkinned is scaled.

 

 

Problem:

The feet are going through the ground cause of the scaling.

This is a logical behavior I know. But I can't find any way to correct the z-position of the ObjectMeshSkinned.

 

 

For and hints I'm very thankful!

[ulf.schroeter]

This works fine and the whole ObjectMeshSkinned is scaled.

 

 

I don't think scaling the whole character via bone matrix is a valid/good approach. Maybe you should try using Node::setScale( vec3 ) instead and use ObjectMeshSkinned bounding box dimensions/center for z-coordinate correction.

[manuel.gysin]

I don't think scaling the whole character via bone matrix is a valid approach. Maybe you should try using Node::setScale( vec3 ) instead.

 

The above example is not the best one.

We are planing the scale some other bones too, and so Node::setScale( vec3 ) is not an option for us.

The same problem will occur if I scale the legs bones, the feet are going through the ground.

[Guest extaliones]

Please, upload the test scene which demonstrates the problem.

[manuel.gysin]

Hi extaliones

 

 

Here is the scene:

 

bone_scaling.rar

 

 

There are two sliders, first one the scale Bip01, second one to scale Bip01 L Thigh.

Bone transform and mesh position are logged to console.

[manuel.gysin]

I think I found something:

 

Changed back to getWorldBoneTransform().

I see a change in *.m22 after scaling a bone:

 

float initM22;
initM22 = initialTransformValues[_switch].m22;

float newM22;
newM22 = mat4(character.getWorldBoneTransform(character.findBone("Bip01"))).m22;

float zCorrection;
zCorrection = (newM22 - initM22) * 100;

character.setPosition(vec3(-95.559, 7.339, 0.1 * cc + 0.1));

 

This code only works when scaling up at the moment.

[Guest extaliones]

Intersection of scinned mesh with terrain calculates manually in every update function(please, see the code sample "BodyRagDoll inverse kinematics" ragdoll_09.cpp or ragdoll_08.cpp in samples/physics).