UnrealCV Dev For UnrealZoo shared-memory transport

The shared-memory implementation in UnrealCV Dev for UnrealZoo draws on the SPEAR project paper (https://arxiv.org/abs/2607.06701) and source repository (https://github.com/spear-sim/spear).

This section is a closed-build measurement of the UnrealZoo distribution. The test environment was:

  • Windows 11

  • AMD Ryzen 9 5950X, 16 cores and 32 logical processors

  • NVIDIA RTX 6000D

  • Epic Games Unreal Engine 5.7.4

  • 3 independent rounds per table row and transport

  • 10 warm-up captures per transport at the start of every round

  • 20 measured captures per round, or 60 measured captures per table cell

TCP and shared-memory requests were alternated to reduce request-order bias. The reported latency is the arithmetic mean of all 60 end-to-end client samples. TCP timing includes receipt of the complete 32-bit BGRA BMP payload. Shared-memory timing includes the request, JSON parsing, opening the named mapping, and copying every mapped byte. FPS is 1000 / mean latency and therefore represents serialized client acquisition throughput, not unloaded viewport frame rate.

The standard-camera rows use vget /camera/0/lit bmp versus vget /camera/0/lit_shared. Panorama rows use vget /camera/0/panoramic bmp WIDTH HEIGHT versus vget /camera/0/panoramic_shared WIDTH HEIGHT. At 4K, both transports carry the same 33,177,600 pixel bytes; the BMP response has an additional 54-byte header.

Table 2 Standard Camera

Resolution

TCP mean

Shared mean

TCP FPS

Shared FPS

Speedup

480p (640x480)

24.62 ms

15.61 ms

40.62

64.05

1.58x

720p (1280x720)

40.39 ms

12.77 ms

24.76

78.30

3.16x

1080p (1920x1080)

62.63 ms

11.14 ms

15.97

89.77

5.62x

2K (2560x1440)

93.75 ms

10.39 ms

10.67

96.20

9.02x

4K (3840x2160)

224.76 ms

15.34 ms

4.45

65.21

14.66x

8K (7680x4320)

713.61 ms

55.25 ms

1.40

18.10

12.92x
Table 3 Panorama

Resolution

TCP mean

Shared mean

TCP FPS

Shared FPS

Speedup

480p (640x480)

66.21 ms

46.74 ms

15.10

21.39

1.42x

720p (1280x720)

77.90 ms

49.40 ms

12.84

20.24

1.58x

1080p (1920x1080)

103.37 ms

56.70 ms

9.67

17.64

1.82x

2K (2560x1440)

136.46 ms

61.85 ms

7.33

16.17

2.21x

4K (3840x2160)

250.10 ms

77.47 ms

4.00

12.91

3.23x

8K (7680x4320)

878.86 ms

177.02 ms

1.14

5.65

4.96x

MQRC

MQRC uses vget /camera/0/mqrc/lit bmp versus vget /camera/0/mqrc/lit_shared. Both paths return the same BGRA8 pixel payload, so the comparison includes MQRC rendering and HDR-to-BGRA8 conversion as well as transport. All 720 measured MQRC requests below succeeded.

Table 4 Movie Quality Render Component

Resolution

TCP mean

Shared mean

TCP FPS

Shared FPS

Speedup

480p (640x480)

41.73 ms

20.89 ms

23.96

47.87

2.00x

720p (1280x720)

59.10 ms

26.80 ms

16.92

37.31

2.21x

1080p (1920x1080)

112.45 ms

36.62 ms

8.89

27.30

3.07x

2K (2560x1440)

170.31 ms

54.72 ms

5.87

18.27

3.11x

4K (3840x2160)

298.29 ms

108.78 ms

3.35

9.19

2.74x

8K (7680x4320)

1243.12 ms

350.26 ms

0.80

2.85

3.55x

Cross-simulator comparison

The following table is an additional product-level comparison against CARLA, SimWorld, and AirSim. It does not replace the UnrealZoo measurements above. The UnrealCV shared-memory column was measured using the current UnrealCV development build and vget /camera/0/lit_shared.

Each result uses three rounds, ten warm-up captures per round, and twenty measured captures per round, for 60 measured samples per cell. FPS is 1000 / arithmetic mean client latency. Simulators ran serially and offscreen.

Table 5 Mean latency / effective FPS

Resolution

UnrealCV shared

CARLA

SimWorld

AirSim

Fastest

UnrealCV rank

640x480

20.34 ms / 49.16 FPS

14.30 ms / 69.94 FPS

54.82 ms / 18.24 FPS

14.51 ms / 68.91 FPS

CARLA

3

1280x720

21.92 ms / 45.62 FPS

20.37 ms / 49.09 FPS

86.49 ms / 11.56 FPS

26.42 ms / 37.85 FPS

CARLA

2

1920x1080

42.36 ms / 23.61 FPS

36.94 ms / 27.07 FPS

128.09 ms / 7.81 FPS

77.00 ms / 12.99 FPS

CARLA

2

2560x1440

44.65 ms / 22.40 FPS

57.44 ms / 17.41 FPS

194.84 ms / 5.13 FPS

124.48 ms / 8.03 FPS

UnrealCV shared

1

3840x2160

61.52 ms / 16.25 FPS

119.28 ms / 8.38 FPS

388.32 ms / 2.58 FPS

256.77 ms / 3.89 FPS

UnrealCV shared

1

7680x4320

120.78 ms / 8.28 FPS

469.24 ms / 2.13 FPS

1438.66 ms / 0.70 FPS

960.71 ms / 1.04 FPS

UnrealCV shared

1

AirSim returns three-byte RGB pixels; the other columns use four-byte BGRA pixels. The simulators use different scenes and rendering pipelines, so this is an end-to-end acquisition comparison rather than a transport-only test.