Debugging the graphic performance of a level is vital to understand which parts are causing the bottleneck. It can also be used to find bugged/incorrect meshes or entities.
Start Depth.exe in Dev mode and then press F1 to bring up the Debug Toolbar. The two groups that are important are the “Debug texts” and “Graphics Debug”.
The important checkboxes here are Show FPS, Show Memory Usage and Show Render Info. These will tell you how costly
the rendering of the scene is.
Shows how fast the level is running.
To be able to find which parts of the scene that takes up the most performance you can use these special render modes.
Pauses the occlusion culling and renders the scene with the occlusion culling from before the checkbox was ticked. This is used to see how effective the occlusion culling is in the specific scene. After activating this you can press F7 to fly around and look at the scene from another angle to see where the culling fails. Activating this will disable rendering of translucent objects since they can be unstable.
On the left image you can see what the player can see. It looks like only a few walls, some lockers and a door is rendered. On the right the camera has been moved back and it is now possible to see all the objects that get rendered on this frame. A lot more than what it looks like on the left.