Improved Center of Rotation [Rotation/Translation Mode]

[rechenknecht]

I found the Rotation/Translation Mode and its settings to be convoluted and behaviour like the custom center of rotation are not explicitly communicated.
Tbh, I thought that a custom center of rotation needs to be implemented. Turns out that it exists, but is overwritten by the bounding box center upon starting the Rotation/Translation Mode. Selecting a new rotation center within the mode allows for a custom rotation center.

I plan to make this more apparent by:

• ... having a checkbox whether the bounding box center shall overwrite the rotation center
  ... allow input of a specific rotation center (cf. this request)
  ... give a shortcut to the Select Roation Center tool within the Rotation/Translation Mode to communicate the chance to select a roation center more clearly.

I'd love feedback whether this is in the spirit of CC and if there is behaviour I've missed.

[daniel]

Hum, that's probably because the ability to change the CoR has been introduced later than the Rotation/Translation mode...

Adding an option specifically for this looks like very 'niche' and is a bit of a pain (but of course if someone is willing to add it, why not). The shortcut is a very good idea though.

By the way, is the 'double clicking' feature still active/working when this tool runs?).

[rechenknecht]

It does work but unreliably.
The behaviour feel buggy, but I have not understood all the interactions yet:

• double click/Pick Rotation Center without R/T mode works as intended
• double click with R/T paused works as intended for both the cameras CoR and the CoR used in the R/T tool
• double click with R/T unpaused only affects the cameras CoR (not R/T tool)
• Pick Rotation Center tool with R/T (paused & unpaused) only updates CoR used in the R/T tool

This becomes more confusing when drawing the CoR permanently. It visualizes how the CoR visually is only updated when the update affects the camera, i.e. it is not a reliable visualization of the CoR in the R/T tool.
I think this stems from which window is `active` when `doPickRotationCenter()` is called.

I've succesfully implemented a shortcut to the Pick Rotation Center tool but did not yet manage resolving the visual inconsistency.
Next up is the logic to update the R/T tools center of rotation to the cameras CoR.
Then I hope to fix the visuals

[rechenknecht]

Hi Daniel, can you help and point me in the right direction of:

1. how would widget (not mainWindow) (or its window) listen to an event of the PickingHub (like R/T tool to the picking of a point)?
It seems like another widget cannot listen to the same events, as it does not have the pickingWindow required to perform window specific tasks during `onItemPicked()`

2. is there an intended way for a widget to pass information to its window (like the Rotation Center coordinates)?
`rotationCenter` currently lives within `ccGraphicalTransformationTool` which means that I cannot draw its Position within the active Window without significant changes to the access specifiers

Thank you in advance!

[daniel]

I think the simplest way would be for the ccGraphicalTransformationTool to add a sphere to the 3D display, and change this sphere center to match the rotation center?

[mipec]

Hi, I've been using CC for 3 years and for me, an easy custom rotation center is a very desired feature. Sphere is a good idea, I think.
Also, this should be available for multi-entity selection too.