#EnvMapTool - Cross-platform tool for working with environmental maps.

Performs a set of different actions:

• Converts cube map to sphere map
• Converts sphere map to cube map
• Blurs cubmap
• Assembles cubemaps from a set of images
• Disassembles cubemap to a set of images

Supported formats fow read/write:

• DDS. Not compressed.
• TARGA
• PNG

#Usage: Input and output files can be specified in two ways:

• As single file. Use keys -i / -o
• As six files that represent x+, x-, y+, y-, z+, z- faces, use keys -I / -O

Specify output format with key -f. It can be: TGA, PNG, DDS. For example -f PNG. Default is TGA.

Specify desired action:

• cube2sphere - converts cube map to sphere map
• sphere2cube - converts sphere map to cube map
• blurCubemap - blurs cubemap using Monte Carlo method. Accurate but slow approach.
• fastBlurCubemap - blurs cubemap using Monte Carlo method. Inaccurate but fast approach.
• convert - this action does nothing. Should be used to convert cubemap from one format to other.

If you specifed a single file for output, that does not support multiple faces (not DDS format), than omly one face will be written. This face can be specified by flag -F

You may specify gamma for input texture -g, and gamma for output texture -G. Default is 2.2

You may specify size of output texture using keys -W and -H.

For actions blurCubemap and fastBlurCubemap you may set bluring radius by use of key -b

For action blurCubemap blur quality can be specified by key -q. Effects the number of samples in Monte Carlo integration. Reasonable values are between 4 - 10. Large values will increase calculation time dramatically. Default is 4

#Exapmles

##Converting DDS to a series of png files: Let we have cubemap in DDS format: uffizi_cros.dds To convert it to six *.png files that represent x+, x-, y+, y-, z+, z- faces you need to execite following command:

EnvMapTool -i uffizi_cros.dds -O 1.png -O 2.png -O 3.png -O 4.png -O 5.png -O 6.png -f PNG convert

The output will be:

##Converting DDS cubemap to sphere map Lets convert uffizi_cros.dds to sphere map and specify size of sphere map of 765x765:

EnvMapTool -i uffizi_cros.dds -o sphere.png -W 765 -H 765 -f PNG cube2sphere

##Converting sphere map to cubemap Lets convert generated in previous example sphere map to a series of png texture of size 256x256:

EnvMapTool -i sphere.png -O xp_.png -O xm_.png -O yp_.png -O ym_.png -O zp_.png -O zm_.png -W 256 -H 256 -f PNG sphere2cube

##Bluring cubemap using Monte-Carlo approach and converting it to spheremap:

EnvMapTool -i uffizi_cros.dds -O 1.png -O 2.png -O 3.png -O 4.png -O 5.png -O 6.png -W 256 -H 256 -f PNG blurCubemap -b 60 -q 10
EnvMapTool -I 1.png -I 2.png -I 3.png -I 4.png -I 5.png -I 6.png -o bluredSphere.png -W 765 -H 765 -f PNG cube2sphere

##The same as above, but using fast blur:

EnvMapTool -i uffizi_cros.dds -O 1.png -O 2.png -O 3.png -O 4.png -O 5.png -O 6.png -f PNG fastBlurCubemap -b 30
EnvMapTool -I 1.png -I 2.png -I 3.png -I 4.png -I 5.png -I 6.png -o fastBluredSphere.png -W 765 -H 765 -f PNG cube2sphere

##Detailed usage:

USAGE: 

   ./EnvMapTool  {-o <Output file>|-O <Output files> ... } {-i <Input file>
                 |-I <Input files> ... } [-f <Output format>] [-F <Face to
                 write>] [-q <Blur quality>] [-b <Blur radius>] [-l] [-g
                 <Input gamma>] [-G <Output gamma>] [-H <Output texture
                 height>] [-W <Output texture width>] [--version] [-h]
                 <cube2sphere|sphere2cube|blurCubemap|fastBlurCubemap
                 |convert>


Where: 

   -o <Output file>,  --output <Output file>
     (OR required)  The output texture file.
         -- OR --
   -O <Output files>,  --outputSequence <Output files>  (accepted multiple
      times)
     (OR required)  The output texture files for cube map. You need specify
     six files: xp, xn yp, yn, zp, zn


   -i <Input file>,  --input <Input file>
     (OR required)  The input texture file. Can be of the following
     formats: *.tga, *.png, *.dds
         -- OR --
   -I <Input files>,  --inputSequence <Input files>  (accepted multiple
      times)
     (OR required)  The input texture files for cube map. You need specify
     six files: xp, xn yp, yn, zp, zn. WARNING! All the files MUST be the
     same format and size!


   -f <Output format>,  --format <Output format>
     Output texture file format. Can be one of the following "TGA", "DDS",
     "PNG". Default TGA.

   -F <Face to write>,  --faceToWrite <Face to write>
     If cubemap texture is written to format that does not support faces,
     this face will be written

   -q <Blur quality>,  --blurQuality <Blur quality>
     Effects the number of samples in Monte Carlo integration. Reasonable
     values are between 4 - 8. Large values will increase calculation time
     dramatically. Default is 4

   -b <Blur radius>,  --blurRadius <Blur radius>
     Gaussian blur radius. Default is 10.0

   -l,  --leaveOuter
     If flag is set, than while cubemap -> sphere transform area around the
     sphere circule are not filled black, but represent mathematical
     extrapolation.

   -g <Input gamma>,  --inputGamma <Input gamma>
     Gamma of input texture. Default is 2.2

   -G <Output gamma>,  --outputGamma <Output gamma>
     Gamma of output texture. Default is 2.2

   -H <Output texture height>,  --outputHeight <Output texture height>
     Height of output texture. Default is the same as input, or 4 times
     upscaled in case of cube2sphere transform, or 4 times downscaled in
     case of sphere2cube transform

   -W <Output texture width>,  --outputWidth <Output texture width>
     Width of output texture. Default is the same as input, or 4 times
     upscaled in case of cube2sphere transform, or 4 times downscaled in
     case of sphere2cube transform

   --version
     Displays version information and exits.

   -h,  --help
     Displays usage information and exits.

   <cube2sphere|sphere2cube|blurCubemap|fastBlurCubemap|convert>
     (required)  Action. Can be:

     	cube2sphere - Converts cube map texture to spherical map

     	sphere2cube - Converts spherical map texture to cube map

     	blurCubemap - Gaussian blur of cubemap

     	convert - Do nothing. Just to convert txture from one format to
     other