Limit rotation of bone in gdscript

[bronygamedev]

Godot Version

4.2.1

Question

I’m making an open source 3d fps game, and replacing a capsule with a 3d model, the problem I’m having is I can’t find a reliable way to keep the bone from rotating in the x axis too far.
repo

Code

func _input(event):
	if event is InputEventMouseMotion:
		rotate_y(deg_to_rad(-event.relative.x * mouse_sensitivity))
		# Get the current pose of the bone
		var bonePose = skel.get_bone_global_pose(17)
		# Save the original position
		var original_position = bonePose.origin
		# Define the rotation axis as the X axis
		var axis = Vector3(1, 0, 0)
		# Define the rotation angle based on relative.x
		angle = event.relative.y * mouse_sensitivity * VERTICAL_sensitivity
		#angle = clamp(angle, deg_to_rad(-0.671), deg_to_rad(0.265)) # this dose not work
		# Apply the rotation to the pose
		bonePose = bonePose.rotated(axis, angle)
		# Reset the position to the original one
		bonePose.origin = original_position
		# Set the new pose of the bone
		skel.set_bone_global_pose_override(17, bonePose, 1.0, true)

[award]

@bronygamedev

#angle = clamp(angle, deg_to_rad(-0.671), deg_to_rad(0.265)) # this dose not work

The issue seems to be that you’re clamping the input but not the result. So it’s clamping how far it can move in a single frame, but not overall.

Instead, I’d suggest using an accumulator (just a float you add to or subtract from when you move the mouse), clamping the accumulator, and then using that to lerp between the two angles you want.

[bronygamedev]

@award

and then using that to lerp between the two angles you want

ok how would you do that?

[award]

accum += event.relative.x * scalar
accum = clampf(accum,0.,1.)
var angle = lerp_angle(angle_a, angle_b, accum)
skel.set_bone_pose_rotation(17, Quaternion(axis, angle))

[bronygamedev]

I don’t quite get how to use your code but I did figure it out.
here’s what I ended up with

func _input(event):
	if event is InputEventMouseMotion:
		rotate_y(deg_to_rad(-event.relative.x * mouse_sensitivity))
		# Get the current pose of the bone
		var bonePose = skel.get_bone_global_pose(17)
		# Save the original position
		var original_position = bonePose.origin
		# Define the rotation axis as the X axis
		var axis = Vector3(1, 0, 0)
		# Define the rotation angle based on relative.x
		angle = event.relative.y * mouse_sensitivity * VERTICAL_sensitivity
		# Apply the rotation to the pose
		bonePose = bonePose.rotated(axis, angle)
		# Changes the basis to a euler
		var bonePosEuler = bonePose.basis.get_euler()
		# Clamps that euler
		bonePosEuler.x = clamp(bonePosEuler.x,-0.671,0.265)
		# Turns the euler into a bias
		bonePose.basis = Basis().from_euler(bonePosEuler)
		# Reset the position to the original one
		bonePose.origin = original_position
		# Set the new pose of the bone
		skel.set_bone_global_pose_override(17, bonePose, 1.0, true)

[award]

Awesome! You did it without an accumulator, and that way works just fine too.