There is an empty scene with one standard cube. If you change its scale to (5;5;1), then the fps does not drop. But if I change it to (5; 10; 1) my fps drops to ~30.
If I move the camera away from the cube with the scale (5;10;1), then the fps is again 60. Maybe I have wrong camera settings or something else.
How to achieve high fps without moving the camera away?
p.s. The fps does not drop in the editor. Only after launching on android. Unity version 2020.3.18f1. Tried on another version same problem.
cube with scale(5;10;1) and camera is distant
CodePudding user response：
From some of Unity's documentation on transforms
Performance Issues and Limitations with Non-Uniform Scaling Non-uniform scaling is when the Scale in a Transform has different values for x, y, and z; for example (2, 4, 2). In contrast, uniform scaling has the same value for x, y, and z; for example (3, 3, 3). Non-uniform scaling can be useful in a few select cases but should be avoided whenever possible.
Non-uniform scaling has a negative impact on rendering performance. In order to transform vertex normals correctly, we transform the mesh on the CPU and create an extra copy of the data. Normally we can keep the mesh shared between instances in graphics memory, but in this case you pay both a CPU and memory cost per instance.
I'm not certain if your Z's scale matters in this case, because you're only rendering the x-y plane. I can't comment for certain on why the performance hit is reduced as you increase your camera distance. I suspect Unity has some intelligent vertex manipulation going on to simplify rendering of distant objects, saving you on CPU cost.
That being said, try to avoid non-uniform scaling. Primitives should typically only be used as placeholders.
CodePudding user response：
The problem may be due to the fact that more pixels is rendered (fragment shader is executed for every one) when the object is scaled up. The other hint is that when you move the camera far from the object the frame rate is increased as the rendered object generates fewer pixels.
As you mentioned that the program runs on Android, changing a regular shader to mobile shader may improve the performance.