Tracking Transforms (BeforeTransformObjects Event)

[jakemurphy0118 (Jake Murphy)]

I would like to track all the transformations which occur to certain objects in Rhino from import to purge.

I discovered that a python script which calls rhinoscriptsyntax.MoveObjects(object_ids, translation) produces events:
ReplaceRhinoObject
DeleteRhinoObject
AddRhinoObject

but no BeforeTransformObjects event.

Is this intended behavior and are there other situations in which objects are transformed but do not produce this event?

[dale (Dale Fugier)]

doc.Objects.Transform don't fires the RhinoDoc.BeforeTransformObjects event

Hello, I think that there is a bug in RhinoDoc.BeforeTransformObjects event. It seems that the event is fired only if the transformation of the objects is done directly by the user using the Rhino commands. Instead, if I try to transform the document’s objects with doc.Objects.Transform(obj_ref, xform, true) in a custom command, the event RhinoDoc.BeforeTransformObjects is not fired. Is it a bug or is it the correct behaviour? Thanks in advance

[jakemurphy0118 (Jake Murphy)]

Thank you.

Is the method RhinoObject.OnTransform(Transform transform) also only called or triggered by commands that inherit from TransformCommand?

[dale (Dale Fugier)]

Hi @jakemurphy0118,

Yes, I believe this is the case.

Commands that inherit from TransformCommand include Move, Copy, Scale, etc.

– Dale

[jakemurphy0118 (Jake Murphy)]

I discovered that RhinoObject.OnTransform is called following a call to rhinoscriptsyntax.MoveObjects while BeforeTransformObjects does not fire. I’ve attached a plugin and script to help demonstrate this.
TrackingTransforms.zip (35.0 KB)
centerObject.py (569 Bytes)

I might be able to use the custom object method to track transformations; however, this feels inconsistent and not what you would expect based on the RhinoDoc events.

Edit:
Yes, you can do this with CustomObjects. Instead of performing accounting of transforms in BeforeTransformObjects handlers, perform the accounting in the custom object’s OnTransform overridden method.