Virtual Textures Dealing with Enormous Texture-Based Resources

Transcription

1 Virtual Textures Dealing with Enormous Texture-Based Resources 1

2 Textures 2

3 Textures 3

4 Mipmaps 4

5 Mipmaps 5

6 Real life problems Problems: Limited amount of resources (avg. 256 MB) Large variation in system resources Maximum texture sizes from: fra 2048 x 2048 til 8192 x 8192 Atomic Resource 6

7 Real life problems Problems: Limited amount of resources (avg. 256 MB) Large variation in system resources Maximum texture sizes from: fra 2048 x 2048 til 8192 x 8192 Atomic Resource 6

8 Real life problems Problems: Limited amount of resources (avg. 256 MB) Large variation in system resources Maximum texture sizes from: fra 2048 x 2048 til 8192 x 8192 Atomic Resource 6

9 Real life problems Problems: Limited amount of resources (avg. 256 MB) Large variation in system resources Maximum texture sizes from: fra 2048 x 2048 til 8192 x 8192 Atomic Resource Solution for large models: Repeating textures Blending 6

10 Repeating Textures 7

11 Repeating textures 8

12 Texture blending 9

13 Static handling of Texture budget Using too much memory? Permanently reduce the texture resolution Load lower mip map levels 10

14 Static handling of Texture budget Using too much memory? Permanently reduce the texture resolution Load lower mip map levels 10

15 Static handling of Texture budget Using too much memory? Permanently reduce the texture resolution Load lower mip map levels 10

16 Static handling of Texture budget Using too much memory? Permanently reduce the texture resolution Load lower mip map levels 10

17 Observations 11

18 Observations Large Textures All points in a surface can be truly unique Artists can add all the details to the texture they want 11

19 Observations Large Textures All points in a surface can be truly unique Artists can add all the details to the texture they want Texture loading with higher granularity Load only visible parts of the texture 11

20 Observations Large Textures All points in a surface can be truly unique Artists can add all the details to the texture they want Texture loading with higher granularity Load only visible parts of the texture Load Textures Runtime: Artists/developers: No headaches from keeping texture budgets! Smoother scaling for different hardware configurations Artists can (in theory) work in arbitrary resolution 11

21 The Method 12

22 Basic Data Structures 13

23 Flow 14

24 Calculation of visible tiles Readback of the framebuffer: 15

25 Barrett s Fragment shader 1 float mipmaplevel = calcmipmaplevel(uv * texturesize); 2 float2 tilepos = floor(uv * indirectionsize); 3 tilepos /= 256.0; 4 float2 tilepos_low = frac(tilepos); 5 float2 tilepos_high = floor(tilepos); 6 color.bg = floor(tilepos_low * )/255.0; 7 color.r = (tilepos_high.x + tilepos_high.y * 16)/255.0; 8 color.a = (mipmaplevel + textureid * 16)/255.0; 9 10 float calctexturemipmaplevel(float2 uv) { 11 float2 dtdx = dfdx(uv); 12 float2 dtdy = dfdy(uv); 13 float2 dtex = dtdx*dtdx + dtdy*dtdy; 14 float mindelta = max(dtex.x,dtex.y); 15 float miplevel = max(0.5 * log2(mindelta), 0.0); 16 return miplevel; 17 } 16

26 Barrett s Fragment shader 1 float mipmaplevel = calcmipmaplevel(uv * texturesize); 2 float2 tilepos = floor(uv * indirectionsize); 3 tilepos /= 256.0; 4 float2 tilepos_low = frac(tilepos); 5 float2 tilepos_high = floor(tilepos); 6 color.bg = floor(tilepos_low * )/255.0; 7 color.r = (tilepos_high.x + tilepos_high.y * 16)/255.0; 8 color.a = (mipmaplevel + textureid * 16)/255.0; 9 10 float calctexturemipmaplevel(float2 uv) { 11 float2 dtdx = dfdx(uv); 12 float2 dtdy = dfdy(uv); 13 float2 dtex = dtdx*dtdx + dtdy*dtdy; 14 float mindelta = max(dtex.x,dtex.y); 15 float miplevel = max(0.5 * log2(mindelta), 0.0); 16 return miplevel; 17 } 17

27 TD-texture 18

28 TD-texture Texture usage: 5 texture types 4096 x 4096 Usage: 80 MB 18

29 TD-texture Texture usage: 5 texture types 4096 x 4096 Usage: 80 MB 18

30 TD-texture Texture usage: 5 texture types 4096 x 4096 Usage: 80 MB My fragment shader: 1 color = tex2d(tdtexture, vertexin.uv * coordscale); 2 color.w = tex2dbias(tdtexture, vertexin.uv, mipbias + resolutionbias).w; 18

31 Tilbagelæsning Tilbagelæsning fra grafikkort til systemhukommelse 19

32 Which tiles to load first? Screen area prioritized Based on error metric: Mip map level 20

33 Which tiles to discard? First In First Out Least Frequently Used Least Recently Used Weighted Least Recently Used 21

34 Updating the Indirection Map 22

35 Updating the Indirection Map 23

36 Rendering 24

37 Rendering 25

38 Visual Results Screenshots 26

39 Resultater Resultater 27 Resultater

40 Diskussion Diskussion 28 Diskussion

41 Resultater: Tilbagelæsning 29

42 Resultater: Tilbagelæsning 30

43 Resultater: Tilbagelæsning 31

44 Resultater: tilbagelæsning + CPU 32

45 Resultater: HDD read 33

46 Resultater: Hvilke tiles skal indlæses? 34

47 Resultater: Hvilke tiles skal kasseres? 35

48 The demo Virtual Textures: 36

49 The demo Virtual Textures: Efficient handling of giant textures: Demo: 128k x 128k, theoretical: 2M x 2M (16 TB) 36

50 The demo Virtual Textures: Efficient handling of giant textures: Demo: 128k x 128k, theoretical: 2M x 2M (16 TB) Texture usage for a 20 GB texture: 17 MB 36

51 The demo Virtual Textures: Efficient handling of giant textures: Demo: 128k x 128k, theoretical: 2M x 2M (16 TB) Texture usage for a 20 GB texture: 17 MB Frame rate: FPS (8800GT) 36

52 Demo time 37

53 Future work Prediction of visible tiles Camera vector A priori map Virtuel Terrain Height map as a Virtual Texture Other uses than games Browsing pictures Google Earth ish applications Streaming Casual Games with Instant Game Play 38

54 Contributions Contributions Calculating visible tiles at greater precision with 2 lines of code Simple, but effective tile prediction method New strategies for prioritizing tiles Faster methods for critical tasks in the VT-system 39

55 40 Konklusion

56 Thank you! Andreas Bærentzen, DTU Carsten Kjær, Dalux Daniel Povlsen, Aptocore Martin Mittring, CryTek GmbH Sean Barrett Per Rasmussen Hardware provided by HwT.dk 40 Konklusion

57 Media 41

58 Media Seek time is a killer: x 256 = 650KB 41

59 Reading tiles from media 42

60 Reading tiles from media Maximizing throughput MPixels/s: Compression = more MPixels/s Texture Layout on media: minimizing seek time 42

61 Reading tiles from media Maximizing throughput MPixels/s: Compression = more MPixels/s Texture Layout on media: minimizing seek time 42

62 Reading tiles from media Maximizing throughput MPixels/s: Compression = more MPixels/s Texture Layout on media: minimizing seek time 42

63 Reading tiles from media Maximizing throughput MPixels/s: Compression = more MPixels/s Texture Layout on media: minimizing seek time Invalidated by the future: SSD harddrives? 42

64 Diskussion 1 Ulemper ved metoden: Transparente objekter Et ekstra prepass Antal unikke teksturer Pakke flere teksturer i ét VT 8 bit tile-position Kvalitetstab pga. manglende tekstur Højere teksturkomprimering Fjern visuel pops 43

65 Diskussion 2 Ulemper ved metoden : Hastighedstab pga. indirection men mindre state change Genbrug Filtrering Manuel i shader Border padding Hardwareunderstøttelse 44

66 Backup: UTM 45 Litteratur

67 Backup: SVT 46 Litteratur

68 Tilbagelæsning Tilbagelæsning fra grafikkort til systemhukommelse Grundlag for metoden er tilbagelæsning til systemhukommelsen Tendens: hurtigere tilbagelæsning! 47

69 Backup: SVT 48 Litteratur

70 Backup: Teksturrepetition Introduktion Litteratur Metode Resultater Diskussion Konklusion 49 Introduktion

71 Tekstur Introduktion Litteratur Metode Resultater Diskussion Konklusion 50 Teksturrepetition

72 Teksturrepetition Introduktion Litteratur Metode Resultater Konklusion 51 Introduktion

73 Teksturrepetition Introduktion Litteratur Metode Resultater Konklusion 51 Introduktion

74 Teksturrepetition Introduktion Litteratur Metode Resultater Konklusion 51 Introduktion

75 Teksturrepetition Introduktion Litteratur Metode Resultater Konklusion 51 Introduktion

76 Teksturrepetition Introduktion Litteratur Metode Resultater Konklusion 51 Introduktion

77 Resultater: Tekstur download Introduktion Litteratur Metode Resultater Diskussion Konklusion 52 Resultater

78 Resultater: Tekstur download Introduktion Litteratur Metode Resultater Diskussion Konklusion 53 Resultater