Manipulating bones

xyz

kuligs2 Then it doesn't reproduce the initial problem. Create the exact same hierarchy above the joints as initially, with all the same transforms (in Blender and in Godot), just use few bones and no mesh. Some of those parent transforms may be messing the things when transforming from/to local joint spaces, if your code doesn't properly take them into account.

Replicate the initial problem in a minimal project, check if the project is self contained, then post it.

kuligs2

xyz Create the exact same hierarchy above the joints as initially, with all the same transforms (in Blender and in Godot)

i just did that, and i posted the project above. Not sure what you mean joints, but i created new skeleton armature with new bones and simple box mesh. I never rotated armature in blender, not in this or previous projects.

Not sure what you mean..

But later i will play more with this..

But i still dont understand why the additional bones (free floating) are not visible in godot, while they are in blender.

xyz

kuligs2 Your initial complaint was about things moving left-right in the direction opposite of mouse. In your attempt to reproduce that problem in a minimal project, this is apparently no more the case. So what's the actual problem here?

kuligs2

xyz problem is more of a question, why not all bones are visible in correct locations in skeleton3d and why as previously stated the left right movement is flipped in some cases?

I will do more tests.

But i will never be able to replicate the initial face armature because it was hand made (bone placement). And recreating simple skeleton, kinda fixed the left-right movement problem but the floating bone problem is still persistent.

xyz

kuligs2 The bone misplacement is likely due to improper setup in Blender or import/export process. So double check there and try a different file format. If you want to get it checked by somebody else, again make a minimal Blender file that still causes the problem.

When hunting bugs always proceed by cutting down their potential dwelling space little by little until they are completely cornered, hence easy to probe and eventually catch. Just like you'd do with an actual insect buzzing around your house.

kuligs2

xyz Interesting observation, godot cuts off last bone.
Previously in blender..

Added more bones

Now the root bones are visible in godot

Global transforms seem to be correct now, (new blend file, reimpored from scratch)

And now manipulating the root bone of that bone chain works kinda, still jumping around like mad sometimes, but manipulating the tip bone is still opposite,random.

So maybe my question is - is there a better way to create manipulators to pose the mesh in godot game? like for character creation, you create hooks/grabbing points for user to grab and stretch to create the face they want, record the position of the manipulations and then on model load apply these manipulations to have the consistent facial deform.

I thought the bone manipulation would be easy, it seem its not so...

Tomcat

kuligs2 So maybe my question is - is there a better way to create manipulators to pose the mesh in godot game?

If I understand correctly, you're trying to use bones for what is normally done with shapekeys. That's a very interesting approach. I'll keep an eye on the topic. My plan is to start experimenting on this topic in about a month

But i will never be able to replicate the initial face armature because it was hand made (bone placement).

It's a strange approach to learnflow. Usually first, as a base, do something simple that can always be easily repeated.

kuligs2

@xyz also i noticed this, that the old project had the node rotated 180 deg, and this messes up the transforms. and manipulations.

mrcool982

kuligs2 lol I was about to suggest that your origin axis or something to that effect was flipped in Blender

kuligs2

I think i know whats the problem. When the ball is clicked it rotates to look at camera, but when ball is moved the bone sets the ball global position and transform and so the ball rotates back facing away or whatever and so this messes up the position left-right, so in one frame it tries to go left in other right because it flips from looking at camera to the transform of the bone wich is different..

Ill try to fix this tomorrow. 😃

xyz

kuligs2 Why do you need to rotate the ball? Btw if a purpose of this ball gizmo is just to move a bone in the screen plane then you can use a 2D draggable gizmo, project its position onto the constrain plane and move a bone directly to that position.

kuligs2

Tomcat It's a strange approach to learnflow. Usually first, as a base, do something simple that can always be easily repeated.

imo this is as simple as it can get using sort of production mock up models.. i mean why would i try to do this on a cube mesh with one bone where if you start adding more bones it gets very complex?

Also this way i learn how to and not to create bones in blender.

Tomcat If I understand correctly, you're trying to use bones for what is normally done with shapekeys.

whats a shape key?

xyz uhm, i think i did that because i needed the x/y/z axis to be in aligned position with the mouse positive negative x/y axis so that it could translate without the trying to convert them somehow i cant even imagine right now..

xyz

kuligs2 xyz uhm, i think i did that because i needed the x/y/z axis to be in aligned position with the mouse positive negative x/y axis so that it could translate without the trying to convert them somehow i cant even imagine right now..

Yeah but you don't need that at all. The orientation/basis of the gizmo or of the bone is not important as you're just need to set the position to a point calculated by constraining the mouse projection to a plane.

Tomcat

kuligs2 whats a shape key?

Surprising question… well it's a mesh change (similar to what you're doing), just in a different, more traditional way.

kuligs2

xyz Continuing debugging, i noticed:

When i click on the ball (i removed look_at() ) i print out positions of the ball and intersection.

ball_node.gd

if cam != null:
	#look_at(cam.global_transform.origin,Vector3.UP)

	print("interset click0: ", global_position)
	
	temp_plane = Plane(cam.global_transform.basis.z,global_position)

	var RAY_LENGTH = (cam.global_position - global_position).length()*1.1
	var mousepos = get_viewport().get_mouse_position()

	var origin = cam.project_ray_origin(mousepos)
	var end = origin + cam.project_ray_normal(mousepos) * RAY_LENGTH
	var query = PhysicsRayQueryParameters3D.create(origin, end)
	query.exclude = [self]
	query.collide_with_areas = true
	var intersect = temp_plane.intersects_ray(end, cam.global_transform.origin-global_position)
	if intersect:

		ball_position_changed.emit(bone_index, intersect)
		print("interset click1: ", intersect)
		ball_clicked.emit(position)

Clicking the ball that is not related to bones prints out position that is close to real position of the ball.

interset click0: (0, 0.959433, -1.63808)
interset click1: (0.03866, 0.905366, -1.619112)

But when i click the ball that is attached to bone, the ball jumps to some arbitrary location and prints out that wrong location.

While i was writing this, i figured it out i think.

Previously on garbanzo..

func _on_ball_position_changed(bone_index, bone_pos):

	skeleton_3d.set_bone_pose_position(bone_index,bone_pos)

	pass

Working code:

func _on_ball_position_changed(bone_index, bone_pos):
	
	var pos =  bone_pos * skeleton_3d.global_transform
	skeleton_3d.set_bone_pose_position(bone_index,pos)

	pass

So the problem was the transforms3d as per usual..
Another culprit is that skeleton_3d.get_bone_global_pose and skeleton_3d.set_bone_pose_position work in local coord space relative to skeleton.

But.. as per usual, some things are still not working.. 😃.. In the video i try to move the child-bone and this messes up everything.. mowing root-bone works as expected.

Still need to work on the child node manipulations..

xyz

kuligs2 How do you "attach" a ball to a bone?

kuligs2

xyz

func get_bones():
	var bone_count = skeleton_3d.get_bone_count()
	
	if bone_count <1:
		return
	for b_index in range(0,bone_count-1):
		
		var b_pos = skeleton_3d.get_bone_global_pose(b_index)
		var pos =  skeleton_3d.global_transform * b_pos * global_transform

		var new_ball:Ball = ball.instantiate()
		new_ball.ball_position_changed.connect(_on_ball_position_changed)
		new_ball.bone_index = b_index
		new_ball.cam = cam

xyz

kuligs2 This is initialization but balls of child bones are moving when you move a parent ball. How do you update this?

kuligs2

xyz

func _on_skeleton_updated():
	pass
	
	for child:Ball in ball_nodes.get_children():
		var b_pos = skeleton_3d.get_bone_global_pose(child.bone_index)
		var pos =  skeleton_3d.global_transform * b_pos * global_transform
		child.global_transform = pos

xyz

Tomcat Blend shapes are per-vertex animation technique. It has nothing to do with what is happening here. Even skeletal mesh animation is not relevant. The problem very likely boils down to faulty transform calculations.

kuligs2

Tomcat so its a blender thing.. not really what im looking for unless the "end" goal i have in mind can be achieved with this.

I agree with xyz, its always transforms..

Tomcat well i didnt know any other way to do what i want - change for instance character shape.. i havent tested this with baked in animations, how it will all work, but the goal is to have character manipulation thingie, that players can set up their char face or any other bone/mesh the way they want.. with limits tho 😃..

I kinda hate when devs take a shortcut and just give few options to change the hair or have pre baked faces or body types..

I think something similar is in ARK survival game, tho i dont remember if you could adjust face.. i mean if you can adjust bone then face should be no problem.. ??

kuligs2

Tomcat Well, you are right. This is the correct way to go on about for character creation. Now i need to find a good workflow that i could apply to character making..

How did i came to this conclusion?

Well..
First i created the cube with bones and added animation, animating bones. then i imported to my godot (blend file) and with the ball nodes tried to move bones into position, and then play animation. and it reset bone positions.
For this to work i would have to calculate the animation bone transforms relative to what i set the deform to, but that is outside my abilities.
While you could do what maths pros like @xyz does and calculate their way out of situations, i just go the least resistance path 😃..

So the least resistance would be to deform enough the character mesh parts,, create necessary shape keys, animate char like usual with rig and then import the glft file, blend file does not import shape keys, annd use the same bone animation along with shape key values.

Now i need to figure out if you can go above 1.0 value in godot. In blender you can.

EDIT:

This oldschool video shows little bit about how to use blender shapekeys in godot

You dont need that escn importer/exporter, gltf/glb file can do that too. Atleast in blender 4.2.1 and godot 4.3

Tomcat

xyz Blend shapes are per-vertex animation technique.

I mean, both are changes to the meshes. Yeah, in different ways. But they're similar enough in appearance. We don't know the end goal thoroughly. Somehow modifying by bones is supposed to be easier for the engine (so it's sometimes claimed). I want to try it, though I'm still vague about how it might be.

« Previous Page Next Page »