Virtual Textures Dealing with Enormous Texture-Based Resources - - PowerPoint PPT Presentation

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Virtual Textures Dealing with Enormous Texture-Based Resources - - PowerPoint PPT Presentation

Feb 13, 2023 170 likes •969 views

Virtual Textures Dealing with Enormous Texture-Based Resources Anders Scheel Nielsen 1 Anders Scheel Nielsen Textures 2 Anders Scheel Nielsen Textures 3 Anders Scheel Nielsen Mipmaps 4 Anders Scheel Nielsen Mipmaps 5 Anders Scheel

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Anders Scheel Nielsen 1

Virtual Textures

Dealing with Enormous Texture-Based Resources

Anders Scheel Nielsen

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Anders Scheel Nielsen 2

Textures

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Anders Scheel Nielsen 3

Textures

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Anders Scheel Nielsen 4

Mipmaps

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Anders Scheel Nielsen 5

Mipmaps

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Anders Scheel Nielsen 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
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Anders Scheel Nielsen 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
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Anders Scheel Nielsen 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
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Anders Scheel Nielsen 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

Solution for ’large’ models:

  • Repeating textures
  • Blending
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Anders Scheel Nielsen 7

Repeating Textures

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Anders Scheel Nielsen 8

Repeating textures

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Anders Scheel Nielsen 9

Texture blending

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Anders Scheel Nielsen 10

Static handling of Texture budget

Using too much memory?

  • Permanently reduce the texture resolution
  • Load lower mip map levels
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Anders Scheel Nielsen 10

Static handling of Texture budget

Using too much memory?

  • Permanently reduce the texture resolution
  • Load lower mip map levels
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Anders Scheel Nielsen 10

Static handling of Texture budget

Using too much memory?

  • Permanently reduce the texture resolution
  • Load lower mip map levels
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Anders Scheel Nielsen 10

Static handling of Texture budget

Using too much memory?

  • Permanently reduce the texture resolution
  • Load lower mip map levels
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Anders Scheel Nielsen 11

Observations

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Anders Scheel Nielsen 11

Observations

Large Textures

  • All ’points’ in a surface can be truly unique
  • Artists can add all the details to the texture they want
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Anders Scheel Nielsen 11

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
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Anders Scheel Nielsen 11

Observations

Large Textures

  • All ’points’ in a surface can be truly unique
  • Artists can add all the details to the texture they want

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

Texture loading with higher granularity

  • Load only visible parts of the texture
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Anders Scheel Nielsen 12

The Method

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Anders Scheel Nielsen 13

Basic Data Structures

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Anders Scheel Nielsen 14

Flow

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Anders Scheel Nielsen 15

Calculation of visible tiles

Readback of the framebuffer:

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Anders Scheel Nielsen 16

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 * 256.0 + 0.5)/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 }

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Anders Scheel Nielsen 17

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 * 256.0 + 0.5)/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 }

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Anders Scheel Nielsen 18

TD-texture

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Anders Scheel Nielsen 18

TD-texture

Texture usage:

  • 5 texture types
  • 4096 x 4096
  • Usage: 80 MB
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Anders Scheel Nielsen 18

TD-texture

Texture usage:

  • 5 texture types
  • 4096 x 4096
  • Usage: 80 MB
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Anders Scheel Nielsen 18

TD-texture

1 color = tex2D(tdTexture, vertexIn.uv * coordScale); 2 color.w = tex2Dbias(tdTexture, vertexIn.uv, mipBias + resolutionBias).w;

Texture usage:

  • 5 texture types
  • 4096 x 4096
  • Usage: 80 MB

My fragment shader:

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Anders Scheel Nielsen 19

Tilbagelæsning

Tilbagelæsning fra grafikkort til systemhukommelse

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Anders Scheel Nielsen 20

Which tiles to load first?

  • Screen area prioritized
  • Based on error metric:
  • Mip map level
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Anders Scheel Nielsen 21

Which tiles to discard?

  • First In First Out
  • Least Frequently Used
  • Least Recently Used
  • Weighted Least Recently Used
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Anders Scheel Nielsen 22

Updating the Indirection Map

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Anders Scheel Nielsen 23

Updating the Indirection Map

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Anders Scheel Nielsen 24

Rendering

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Anders Scheel Nielsen 25

Rendering

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Anders Scheel Nielsen 26

Visual Results

Screenshots

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Anders Scheel Nielsen 27

Resultater

Resultater

Resultater

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Anders Scheel Nielsen 28

Diskussion

Diskussion

Diskussion

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Anders Scheel Nielsen 29

Resultater: Tilbagelæsning

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Anders Scheel Nielsen 30

Resultater: Tilbagelæsning

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Anders Scheel Nielsen 31

Resultater: Tilbagelæsning

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Anders Scheel Nielsen 32

Resultater: tilbagelæsning + CPU

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Anders Scheel Nielsen 33

Resultater: HDD read

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Anders Scheel Nielsen 34

Resultater: Hvilke tiles skal indlæses?

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Anders Scheel Nielsen 35

Resultater: Hvilke tiles skal kasseres?

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Anders Scheel Nielsen 36

The demo

Virtual Textures:

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Anders Scheel Nielsen 36

The demo

Virtual Textures:

  • Efficient handling of giant textures:

Demo: 128k x 128k, theoretical: 2M x 2M (16 TB)

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Anders Scheel Nielsen 36

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
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Anders Scheel Nielsen 36

The demo

Virtual Textures:

  • Efficient handling of giant textures:

Demo: 128k x 128k, theoretical: 2M x 2M (16 TB)

  • Frame rate: 150-200 FPS (8800GT)
  • Texture usage for a 20 GB texture: 17 MB
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Anders Scheel Nielsen 37

Demo time

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Anders Scheel Nielsen 38

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
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Anders Scheel Nielsen 39

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
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Anders Scheel Nielsen 40 Konklusion

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Anders Scheel Nielsen 40 Konklusion

Thank you! Andreas Bærentzen, DTU Carsten Kjær, Dalux Daniel Povlsen, Aptocore Martin Mittring, CryTek GmbH Sean Barrett Per Rasmussen Hardware provided by HwT.dk Anders.Scheel@gmail.com

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Anders Scheel Nielsen 41

Media

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Anders Scheel Nielsen 41

Media

Seek time is a killer: 10 tiles @ 256 x 256 = 650KB

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Anders Scheel Nielsen 42

Reading tiles from media

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Anders Scheel Nielsen 42

Reading tiles from media

  • Maximizing throughput MPixels/s:
  • Compression = more MPixels/s
  • Texture Layout on media: minimizing seek time
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Anders Scheel Nielsen 42

Reading tiles from media

  • Maximizing throughput MPixels/s:
  • Compression = more MPixels/s
  • Texture Layout on media: minimizing seek time
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Anders Scheel Nielsen 42

Reading tiles from media

  • Maximizing throughput MPixels/s:
  • Compression = more MPixels/s
  • Texture Layout on media: minimizing seek time
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Anders Scheel Nielsen 42

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?
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Anders Scheel Nielsen 43

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
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Anders Scheel Nielsen 44

Diskussion 2

Hastighedstab pga. indirection

  • men mindre state change
  • Genbrug

Filtrering

  • Manuel i shader
  • Border padding
  • Hardwareunderstøttelse

Ulemper ved metoden :

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Anders Scheel Nielsen 45

Backup: UTM

Litteratur

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Anders Scheel Nielsen 46

Backup: SVT

Litteratur

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Anders Scheel Nielsen 47

Tilbagelæsning

Tilbagelæsning fra grafikkort til systemhukommelse

  • Grundlag for metoden er tilbagelæsning til

systemhukommelsen

  • Tendens: hurtigere tilbagelæsning!
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Anders Scheel Nielsen 48

Backup: SVT

Litteratur

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Anders Scheel Nielsen 49

Backup: Teksturrepetition

Introduktion

Introduktion Litteratur Metode Resultater Diskussion Konklusion

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Anders Scheel Nielsen 50

Tekstur

Teksturrepetition

Introduktion Litteratur Metode Resultater Diskussion Konklusion

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Anders Scheel Nielsen 51

Teksturrepetition

Introduktion

Introduktion Litteratur Metode Resultater Konklusion

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Anders Scheel Nielsen 51

Teksturrepetition

Introduktion

Introduktion Litteratur Metode Resultater Konklusion

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Anders Scheel Nielsen 51

Teksturrepetition

Introduktion

Introduktion Litteratur Metode Resultater Konklusion

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Anders Scheel Nielsen 51

Teksturrepetition

Introduktion

Introduktion Litteratur Metode Resultater Konklusion

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Anders Scheel Nielsen 51

Teksturrepetition

Introduktion

Introduktion Litteratur Metode Resultater Konklusion

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Anders Scheel Nielsen 52

Resultater: Tekstur download

Resultater

Introduktion Litteratur Metode Resultater Diskussion Konklusion

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Anders Scheel Nielsen 53

Resultater: Tekstur download

Resultater

Introduktion Litteratur Metode Resultater Diskussion Konklusion