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path9263

On a spatial node calling get_global_transform().basis.get_scale() and scale both return the same values regardless of the global rotation of the node. I want to be able to scale a node by a specific amount along a global axis even if it has been rotated. How do I find a Spatial’s scale values in global XYZ so I can do this?

You can just use your_node.global_scale(scaling_vector) on a spatial node to scale it in world coordinates. Replace your_node with the actual node and scaling_vector with a vector with the scaling amount for each axis.

The problem is that I need to know the starting global scale value to know how much to scale by. Say I have a Spatial Node that has already been scaled and rotated some amount. I want to scale it to be 5 units long on the global X axis. I need to know the starting scale on the global X axis to know how much to scale it by to get it to 5 units long.

Here is how I solved this for anyone who may find this in the future.

# scales the Spatial by the amount in the given global direction
func scaleDirection(amount: Vector3, camRot: Vector3):
var selfQuat = transform.basis.get_rotation_quat() # get the global rotation
var sclXform = Transform(selfQuat) # make it a transform so we can apply it to a vector
var globalScale = sclXform.xform(scale) # convert local scale to scale on global axis'
globalScale = globalScale.abs() # scale should always be positive but rotation can make it negative when converted to global
# when camera is behind the object axis direction must be inverted:
if(camRot.y < 0):
amount.x = -amount.x
pass
if(camRot.y > 90 or camRot.y < -90):
amount.z = -amount.z
pass
# calculate new scale amount because we are not setting the scale directly
var newScale = -amount + globalScale # invert amount here to change side which moves
# actually apply changes
global_scale(newScale)

With this function applied to a Spatial you can set the input value amount to how many units you would like to scale the Spatial in global coordinates. It is not a ratio, for example if your Spatial was already 5 units long on the global X axis and you set amount to (2,0,0) it would scale your Spatial so it was now 7 units long on the global X axis. It should work no matter the Spatials starting rotation or scale. The camera stuff is optional depending on your use case.

Please let me know if there is a simpler way to do this, I have a feeling I have over thought it, but hey, it works!

I get the global scale as follows (edit: note that this only works for unrotated spatials):-

# 'mesh' is the name of the spatial
var scale: Vector3 = Vector3(mesh.global_transform[0][0], mesh.global_transform[1][1], mesh.global_transform[2][2])

From what I can tell unfortunately this breaks if the object is rotated.