Design456: Best practice to minimize CPU demand while redrawing the 3D object?

[mariwan]

I noticed that the redrawing takes too much time when I continuously do resizing(scaling) of the 3D object.

The desired 3D drawing is slow in FreeCAD or I don't know how to make it optimized.
Thinking about drawing the TopoShape object in the Coin3D is not possible. Think about all possible situations. I cannot recreate the 3D object in COIN3D.
The implementation of DirectScale is at
https://github.com/MariwanJ/Design456/b ... tScale.py
I would like to know how you would think about this matter. To understand the problem, please use the DirectScale I have in my Workbench.
For primitive simple object, you don't notice the problem.. But as soon as you use it on a complex object, it lags and take too much time.. FreeCAD might freezes for some seconds.

As the whole project is based on that, I need to find a solution. Please let me know how I do minimize CPU demand.

Why for example redrawing in Autodesk 123D Design is so smooth, you don't notice any redrawing problem? How do other CAD programs redraw the object so quickly?

Your help is appreciated.
Thanks.

https://github.com/MariwanJ/Design456

[carlopav]

I suggest to take a look at Draft WB.
Almost every command do not directly modify the shape, but preview the changes using coin, and then compute the changed shape only once at the end of the transformation. This is done for Draft.Move and Draft.Rotate.
Usually the preview object is called ghost in the code.

Also Draft Scale command do it
https://github.com/FreeCAD/FreeCAD/blob ... le.py#L364
https://github.com/FreeCAD/FreeCAD/blob ... rs.py#L721