We are using Aspose.Slides to generate large preview images of PowerPoint slides in our software. A client recently asked us to take a look at a slide where the preview image showed a triangle upside-down from how it shows on the actual slide. The attached solution reproduces this problem: compare the generated thumbnail tri.png to the tri.pptx file it’s generated from.
It seems that Aspose is ignoring the 3D transform applied to the triangle altogether, so it renders it flipped vertically and in a lighter shade of blue compared to PowerPoint’s renderer. In this case our advice to the client was to remove the 3D transform and position the triangle in 2D since there was no real need to use a 3D transform just to flip a triangle around. However, I thought you should be aware of this limitation.