I'm doing some graphics optimizing tests, especially on PowerVR transparency. Now I made a scene where there are two groups of simple objects. One group has the shape in geometry using diffuse shader and the other with quads using transparency shader. The camera looks through a plane towards a group.
The test was about the "lateness" of PowerVR's Z-tests. And whether or not use better geometry instead of transparencies for e.g leaves or flowers.
The results were not wholly what I expected. The transparency group benefitted from changing the plane from transparent to diffuse by increasing the FPS by 20(expected).
But why is the group without the plane infront so much faster than when the plane is in front?(Not expected) FPS was 38, screenshotting lowered it.
Tests on the geometry group were opposite of what I had learnt in the past few days. There was only 2FPS difference between transparent and diffuse planes. (Not expected). Shouldn't the transparent plane infront cause the whole scene to render as the Z-test is at the bottom of the pipeline?