Difference between revisions of "Du/dv map"

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(elaborated on tutorial a bit)
 
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{{note|<code>$dudvmap</code> is now defunct and is replaced by the <code>[[Refract]]</code> shader. Though, the <code>[[Water_(shader)|Water]]</code> shader still uses a du/dv map for <code>[[$bumpmap]]</code>.}}
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'''du/dv maps''' are used for [[DirectX Versions|DirectX 8]] refractions. If you're a Photoshop user, it's easy to create du/dv maps using [http://developer.nvidia.com/object/nv_texture_tools.html nVidia's texture tools].
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== Creating a du/dv map from a normal map ==
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A du/dv map can be easily created from a normal map in just two steps. You can also do this if you don't want to bother with the nVidia tools. {{note|Work from the source texture (such as a .tga) if possible.}}
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=== Photoshop ===
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#Open the normal map and invert the colours (''Image > Adjustments > Invert'' or {{Key|Ctrl|I}}).
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#Go to ''Colors > Adjust > Brightness/Contrast''.
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##Check "Use Legacy"
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##Set Brightness to -17
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##Set Contrast to 100
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=== Paint Shop Pro ===
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#Open the normal map and invert the colours (''Colors > Negative Image'').
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#Adjust the contrast as high as it will go.
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----
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You now have a finished du/dv map. When converting to a VTF, set the [[Valve Texture Format#Image data format table|format]] to UV88.
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<!--- This doesn't improve du/dv maps at all in my experience.
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DuDv maps with only pure yellow, green, red and black tend to have some artifacts ingame. There you should mix it up a bit with the original normal map. In Photoshop this is best done by puting the normal map as a layer on top of you dudv image set opacity to 50% and blending mode to hard light. -->
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==See also==
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* [[Normal2dudv]] - utility to convert normal maps to dudv maps
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* [[Height2Normal]] - utility to convert height maps to normal maps
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* [http://www.filterforge.com/filters/9557.html Filter Forge]
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[[Category:Material System]]
 
[[Category:Material System]]
If you're a Photoshop user, it's easy to create du/dv maps using [http://developer.nvidia.com/object/nv_texture_tools.html nVidia's texture tools]. (du/dv maps are for DX8 refractions.) But if you're using another program like PaintShopPro, you might have trouble getting the nVidia tools to work. Fortunately, a du/dv map can be easily created from a normal map in just two steps. You can also do this in Photoshop if you don't want to bother with the nVidia tools.
 
 
#Open the normal map. First go to Colors->Negative Image (PaintShopPro) or whatever inverses all the colors in your paint program.
 
#Now go to Colors->Adjust->Brightness/Contrast (or your paint program's equivalent). Leave brightness at 0, but raise contrast as high as it will go.
 
That's all! Just save and you're done..
 

Latest revision as of 19:50, 22 July 2011

Note.png Note: $dudvmap is now defunct and is replaced by the Refract shader. Though, the Water shader still uses a du/dv map for $bumpmap.

du/dv maps are used for DirectX 8 refractions. If you're a Photoshop user, it's easy to create du/dv maps using nVidia's texture tools.

Creating a du/dv map from a normal map

A du/dv map can be easily created from a normal map in just two steps. You can also do this if you don't want to bother with the nVidia tools.

Note.png Note: Work from the source texture (such as a .tga) if possible.

Photoshop

  1. Open the normal map and invert the colours (Image > Adjustments > Invert or Ctrl+I).
  2. Go to Colors > Adjust > Brightness/Contrast.
    1. Check "Use Legacy"
    2. Set Brightness to -17
    3. Set Contrast to 100

Paint Shop Pro

  1. Open the normal map and invert the colours (Colors > Negative Image).
  2. Adjust the contrast as high as it will go.

You now have a finished du/dv map. When converting to a VTF, set the format to UV88.

See also