Help with Spherical Linear Interpolation (SLERP)

HyperDork

So basically I'm trying to do the same thing as [url=http://answers.unity3d.com/questions/443131/smooth-90-degrees-rotation-on-input-infinite-numbe.html]http://answers.unity3d.com/questions/443131/smooth-90-degrees-rotation-on-input-infinite-numbe.html[/url]I'm trying to smoothly rotate a cube centered at the origin 90 degrees (along the x-axis) using the up and down arrow keys in such a way that it is infinitely repeatable. I've modified the only SLERP code for Godot I've been able to find online and, after some minor hair-pulling, here's what I have so far in my _process() function. [code] var t = get_transform() if (start != true): if Input.is_action_pressed("ui_up"): start = true rotTransform = t.rotated(x_axis, PI/2) if Input.is_action_pressed("ui_down"): start = true rotTransform = t.rotated(x_axis, -PI/2) else: thisRotation = Quat(t.basis).slerp(rotTransform.basis,value) value += delta * speed if value >= 0.1 : value = 0 start = false set_transform(Transform(thisRotation,t.origin))[/code]Notice the "0.1" comes out of nowhere. This is because I'm having trouble knowing programmatically exactly when the 90 degree rotation has finished. I've eyeballed it to when the variable value is about 0.1, but I'd like a more surefire way to know when the rotation is done so that my code is more framerate-independent. Any ideas? Perhaps an entirely different implementation of SLERP? Thanks in advance.

HyperDork

Well, in the past few days I have scoured game development Q&A websites and tried over a dozen failed implementations. Getting the cube to rotate on one axis with SLERP was easy, but rotating on two axes was a headache! Fortunately, I've come up with an implementation that allows the cube to rotate with SLERP on two axes at 90 degree intervals using transformation matrices. I hope someone finds this post while frantically googling for rotations on two axes in Godot, so that it may help them with their headache.The following implementation assumes the camera is on/above the z axis and facing the positive z direction. I'm not sure if changing the camera's position will break anything, but just in case.[code]extends KinematicBody#boolean for whether the box is rotatingvar rotating = false#value for SLERPingvar value = 0#axisesvar x_axis = Vector3(1,0,0) #Initial x axisvar y_axis = Vector3(0,1,0) #Initial y axisvar z_axis = Vector3(0,0,1) #Initial z axis#The initial orientationvar matrixFrom#The final orientation after rotationvar matrixTo = Matrix3()#Quat for interpolating between rotationsvar thisRotation#Speed of rotationexport var speed = 2.5 #Identity matrixvar matrix = Matrix3()#Helper variable for storing an axisvar tempfunc ready(): set_process(true)func process(delta): if (rotating != true): if Input.is_action_pressed("ui_up"): matrixFrom = matrixTo matrixTo = matrixTo matrix.rotated(x_axis, PI/2) temp = y_axis y_axis = z_axis z_axis = -temp rotating = true elif Input.is_action_pressed("ui_down"): matrixFrom = matrixTo matrixTo = matrixTo matrix.rotated(x_axis, -PI/2) temp = y_axis y_axis = -z_axis z_axis = temp rotating = true elif Input.is_action_pressed("ui_right"): matrixFrom = matrixTo matrixTo = matrixTo matrix.rotated(y_axis, PI/2) temp = x_axis x_axis = -z_axis z_axis = temp rotating = true elif Input.is_action_pressed("ui_left"): matrixFrom = matrixTo matrixTo = matrixTo matrix.rotated(y_axis, -PI/2) temp = x_axis x_axis = z_axis z_axis = -temp rotating = true else: thisRotation = Quat(matrixFrom).slerp(matrixTo,value) value += delta * speed set_transform(Transform(Matrix3(thisRotation))) if value >= 1: value = 0 set_transform(Transform(matrixTo)) rotating = false[/code]