The introduction of mobile AR means the arrival of more accessible devices, and for developers, a broader range of consumers to target. The good news is that you're "already ready." A stable of universal techniques and best practices can help reduce draw calls and maximize performance without sacrificing fidelity across Gear VR, Oculus Go, and Project Santa Cruz. We'll start with an overview of the devices and basic considerations, and go step by step through the process of reviewing and optimizing textures, scene geometry, and lighting. Attendees interested in Project Santa Cruz will also benefit from an introduction to Unity's profiling workflow. Gabor Szauer - Oculus

2. Optimizing Performance
Across Oculus Mobile
Gabor Szauer
Developer Relations Engineer, Oculus

3. Best balance of quality to file size
Maybe not for UI
ASTC Texture
Compression

4. UNCOMPRESSED
21.3 MB
ASTC COMPRESSED
1.3 MB

5. UNCOMPRESSED
21.3 MB
ASTC COMPRESSED
1.3 MB

6. UNCOMPRESSED
21.3 MB
ASTC COMPRESSED
1.3 MB

7. Half your draw calls!
OpenGL Extension
Renders to frame buffer array
CPU side win
Single Pass Stereo

8. MULTI PASS
SetPass Calls: 46
SINGLE PASS
SetPass Calls: 22

9. Batch Meshes
Atlas Textures
Reduce Number Of
Materials
Further Reducing
Draw Calls

10. UNBATCHED
915 Objects
BATCHED
2 Objects

11. LOTS OF TEXTURES
Unique Materials
More Draw Calls
SINGLE ATLAS
Shared Material
Less Draw Calls

12. 4,306 POLYGONS
2 MATERIALS
4 TEXTURES
2,477 POLYGONS
1 MATERIAL
1 TEXTURE

13. Pixel Light Count
• 1 is ok
• 0 is preferred
Shadows
• hard shadows is ok
• disable shadows preferred
Bake shadow maps if
possible
Light & Shadows

14. Can't avoid additional resolve
Additional resolve: 1ms +
Bake environment lights
Few dynamic shadow casters
Real time shadows

15. Avoid shadow projector
Re-rendering batched
geometry is expensive
Simple quad at feet will do in
most cases
Blob shadows

16. Renders model twice
First render is the model
projected onto plane
No self shadowing
Same limitations as blob
shadows, but looks better
Planar Projection
Shadows

17. Environment should not be lit
in real time
Bake lighting / shadow maps
4096 is a pretty good size
These settings are very
project dependent.
Bake Lighting Data

18. Dynamic characters no
longer receive shadows
from baked objects
Bake Lighting Data

19. Sample light map to make moving
object kind of match lighting
Start with a recast down, then:
Renderer.lightmapIndex
LightmapData.lightmapColor
RaycastHit.lightmapCoord
Sample light map
for shadow value

20. Use light probes!
Fast, easy to set up,
looks great!
Lightprobe shadow
volumes

21. Use light probes!
Fast, easy to set up,
looks great!
Lightprobe shadow
volumes

22. Impostor geometry, just a
quad with some textures
Add particles to make extra
fancy
Fake lighting effects

23. Linear
• More Realistic
• OpenGL ES 3 Required
Gamma
• Less Realistic
• Works Everywhere
Color Space

24. GAMMA LINEAR

25. Per material color grading
Done in forward pass
Use Lookup Table
Edit lookup table in any
image editing application
Per Material
Color Grading

26. Per material color grading
Done in forward pass
Use Lookup Table
Edit lookup table in any
image editing application
Per Material
Color Grading

27. Set to 4x
Use the "Use Recommended
MSAA Level" in OVRManager
when possible
Anti Aliasing

28. 2X MSAA0X MSAA 4X MSAA

29. No reason not to use
OpenGL ES 3
Vulkan fallback is ok
Vulkan is a CPU side win
Graphics API

30. Multithreaded rendering
Static Batching
GPU Skinning
Turn on

31. API Level 23+
Device Filter: ARM
Device filter can make about
10 MB difference in APK size
Other settings

32. Scripting back-end: IL2CPP
Prebake collision meshes
Keep Loaded Shaders Alive
Optimize Mesh Data
Consider these

33. Anisotropic: off
Bone weights: 2
V-Sync: Don't
Everything else

34. Try to get Render Texture
Switches down to 0 if
possible
* Not possible if using
real time shadows
Reduce Resolves

35. Avoid Using Post Effects
Add quad in front of camera
Fade quad to fade scene
Screen Fade

36. VR.WaitForGPU = Wait for Vsynch
If you are making frame rate, there
should be a few milliseconds
of VR.WaitForGPU
Frame Times:
30 FPS = 33.3 ms
60 FPS = 16.6 ms
72 FPS = 13.8 ms
Reading the profiler

38. Internal Unity Profiler
Android Unity internal profiler stats:
cpu-player> min: 15.8 max: 16.9 avg: 16.4
cpu-ogles-drv> min: 0.0 max: 0.0 avg: 0.0
gpu> min: 0.0 max: 0.0 avg: 0.0
cpu-present> min: 0.3 max: 0.6 avg: 0.3
frametime> min: 16.1 max: 17.3 avg: 16.7
batches> min: 5 max: 5 avg: 5
draw calls> min: 5 max: 5 avg: 5

39. Profiling Workflow

40. Useful for measuring general performance
Not useful for knowing what is slow
Not enough info to really optimize
Frames per second

41. OVR Metrics Tool

42. Milliseconds per frame
30 FPS = 33.3 Milliseconds / Frame
60 FPS = 16.6 Milliseconds / Frame
90 FPS = 11.1 Milliseconds / Frame

43. Example: Frame Breakdown
A single frame takes 21.2 ms and waits 12 ms for the next vsynch
The current total frame duration is 33.3 ms
To run at 60 FPS, the frame needs to finish in 16.6 ms
To hit the 60FPS mark, at least 5.2 ms has to be optimized away from this frame
* This example assumes everything runs on one thread to make it easy to read

44. CPU or GPU Bound?
If the frame rate improved, the game was GPU Bound If the frame rate dod not improve, the game was CPU Bound
To determine if a game is CPU or GPU bound: Don't render anything!

45. Use Unity Profiler
CPU Bound

46. If the game is GPU bound, it
can be Vertex of Fill bound.
To determine which, change
render scale to something
small, like 0.01
Did performance improve?
Yes - Fill / Fragment Bound
No - Vertex Bound
GPU Bound

47. Qualcomm Snapdragon Profiler
Mali Graphics Debugger
Renderdoc
Fill Bound

48. Simplify meshes which contain
too many vertices
Consider combining meshes to
reduce draw calls
Cull invisible meshes and
enable LOD on meshes
Vertex Bound

49. Rinse and Repeat
Disable all rendering.
Did performance improve?
GPU or CPU
Bound
No CPU Bound Use instrumented profiler
GPU BoundYes
Vertex or Fill
Bound?
Set render scale to 0.01
Did performance improve?
No
Yes Fill Bound
Vertex Bound
Simplify Shaders
Simplify Geometry
Combine Geometry
Reduce Draw Calls

50. Questions?
Comments...
Rude Remarks?