Tested on versions 15.1 and 15.2.
Loading a pptx with a 3D pie chart and saving it causes the Y rotation to be reset to 15 degrees. Attempting to manually set the Y rotation does not affect the output file.
Attached is an example pptx to use with the following code (C#) to reproduce:
var pres = new Presentation(“Presentation.pptx”);
In the initial pptx the Y rotation is 40 degrees but in the text.pptx output it changes to 15 degree.
Trying to set the value using chart.Rotation3D.RotationY = 40 has no affect. Also this property is loaded with a value of 0.
Any assistance would be appreciated.