VisualizeTexture Command

Overview

Unreal engine has a lot of rendering features that rely on rendering to textures. The data of those render targets can only be indirectly seen through the effects. In order to inspect the data of the internal render targets this console command was created. As a nice side effect you can see which texture are allocated (not INVALID) and what size they have.

VisualizeTexture is a console command that allows to inspect the data of the various internal render targets. It's useful to debug rendering. As the data shown in very low level and heavily platform dependent this toolshould only be used by graphics programmer or very technical people.

Usage

Type "VisualizeTexture" into the unreal console to see how the command can be used:

VisualizeTexture <TextureId> [<Mode>] [UV0/UV1/UV2] [BMP] [FRAC/SAT]:
TextureId:
  0 = <off>
  1 = 330x222 FilterColor
  2 = 1312x880 SceneColor
  3 = 1312x880 SceneColorRaw
  4 = 1312x880 SceneColorFixedPoint  <INVALID>
  5 = 1312x880 SceneDepthZ  <INVALID>
  6 = SmallDepthZ  <INVALID>
  7 = ShadowDepthZ  <INVALID>
  8 = DominantShadowDepthZ  <INVALID>
  9 = 400x400 TranslucencyShadowDepthZ  <INVALID>
  10 = ShadowDepthColor
  11 = DominantShadowDepthColor
  12 = 400x400 TranslucencyShadowDepthColor
  13 = ShadowVariance  <INVALID>
  14 = 1312x880 LightAttenuation
  15 = 656x440 TranslucencyBuffer
  16 = 656x440 TranslucencyBuffer2
  17 = 1312x880 TranslucencyDominantLightAttenuation
  18 = 1312x880 AOInput
  19 = 1312x880 AOOutput
  20 = 1312x880 AOHistory
  21 = 1312x880 VelocityBuffer
  22 = QuarterSizeSceneColor  <INVALID>
  23 = 656x440 FogFrontfacesIntegralAccumulation  <INVALID>
  24 = 656x440 FogBackfacesIntegralAccumulation
  25 = HitProxy
  26 = FogBuffer  <INVALID>
  27 = 330x222 FilterColor2
  28 = 1312x880 DoFBlurBuffer  <INVALID>
  29 = StereoFix
  30 = LUTBlend
  31 = TexturePoolMemory  <INVALID>
Mode (examples):
  RGB   = RGB in range 0..1 (default)
  *8    = RGB * 8
  A     = alpha channel in range 0..1
  A*16  = Alpha * 16
  RGB/2 = RGB / 2
InputMapping:
  UV0   = view in left top (default)
  UV1   = full texture
  UV2   = view in left top with 1 texel border
Flags:
  BMP   = save out bitmap to the screenshots folder (not on console, normalized)
  FRAC  = use frac() in shader (default)
  SAT   = use saturate() in shader
VisualizeTexture 0

The Visualization shader

In order to display values that are not in the color range a monitor can display multiple visualization mode can be used. A shader does some math before the color value is displayed. Colors outside of the range are detected and colors inside the range are wrapping in the 0..1 range (frac instruction). Example: a alpha value of 2.34 becomes 0.34 which is displayed as some dark grey.

Color coding

The on screen text explains how to interpret the colors in the visualize texture mode:

Known issues

• In D3D10 the on screen texture doesn't show up.
• Some textures don't show a size yet (Can be fixed easily in code but we might want to change that code anyway).
• When a texture cannot be displayed (e.g. INVALID) it simply doesn't show up - better would be some image that indicated the texture cannot be used
• Texture are often getting reused so looking at the buffer might only show the last usage. There are solution to this (e.g. index each reused, copy the data or prevent reuse) but those might have other side effects (e.g. more memory usage or alter the output).