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Can normal map be used in animation?

polycounter lvl 13
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guangh69 polycounter lvl 13
I found that normal map deformed when I deformed my chracrer. Does normal map can only be used in suituation where without deformation?

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  • Yozora
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    Yozora polycounter lvl 11
    Are you using an world space, object space or a tangent space normal map?

    You should be using tangent space normal maps for meshes that deform. And the answer to the question is yes, normal maps can be used in animation.
  • Bad Spleen
    You can use two normal maps, and animate the transition between the two maps. This gives quite good effects, if possible, take a look at the T shirts in Fifa, or PES2010 as strong examples.

    -Adam
  • guangh69
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    guangh69 polycounter lvl 13
    Thank you very much.
    I understand.
  • ZacD
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    ZacD ngon master
    Bad Spleen wrote: »
    You can use two normal maps, and animate the transition between the two maps. This gives quite good effects, if possible, take a look at the T shirts in Fifa, or PES2010 as strong examples.

    -Adam

    Also I believe MGS4 used a winkled and a relaxed face normal map in in certain areas it would fade between them depending on the facial expression.
  • pior
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    pior grand marshal polycounter
    Are you using an world space, object space or a tangent space normal map?

    You should be using tangent space normal maps for meshes that deform. And the answer to the question is yes, normal maps can be used in animation.

    This is a misconception here. Tangent space work for anim 'out of the box' with most nm shaders but object can work wery well too, provided you have an appropriate shader doing just that.

    Yup I believe that too Zac, and I am pretty sure Uncharted did that for cloth also.
  • Martin Henriksson
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    Martin Henriksson polycounter lvl 9
    Crysis also had normal map blending for facial animation etc.
  • Gav
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    Gav quad damage
    We did normal map blending for cloth wrinkles on a title I worked on, it took some work but the results were kind of nice. Subtle, but it made a difference. I believe we created a regular normal map that had bigger volume wrinkles for the shirts and then a map that had tighter, sharper wrinkles caused from pulling and stress...then we had a map where each channel would control the visibility of the wrinkle map and swap out the same section of the regular normal map. Obviously, this is in artist's terms and not techy terms :P
  • Xoliul
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    Xoliul polycounter lvl 16
    pior wrote: »
    This is a misconception here. Tangent space work for anim 'out of the box' with most nm shaders but object can work wery well too, provided you have an appropriate shader doing just that.

    Yup I believe that too Zac, and I am pretty sure Uncharted did that for cloth also.

    It's not like a shader that transforms your object space normals with your Bone transform matrix is common practice however. Plus it's a bit heavy on performance.
  • EarthQuake
    Is it that heavy? From what i've been told the savings from not having to convert tangent space into world to render makes up for the slight cost of transforming the OS normals. Which means its pretty much a wash performance wise. Also not needing to store normals/binormals/tangents for the mesh gives a nice little memory gain.
  • guangh69
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    guangh69 polycounter lvl 13
    Thank you very much!
    Today when I was reading Autodesk documents. It says:"
    The other very popular use for tangent space normal maps is the deforming of characters. Because the tangent space normal map defines the details of a character relative to the surface, you can stretch, move and deform your character, and those normal mapped veins on his arm will deform right along with the character. If his arm is turned upside down, the veins will appear as it they are upside down, and so forth. You cannot achieve the same effect with an object space normal map.
    You can see this just by looking at the normal map itself: an object space normal map is really colorful, because it contains vectors that point in lots of different directions, while a tangent space normal map just has variations on up, which makes the whole map shades of blue and purple."
    So I thought object space can't keeping the apperance of normal maps, and tangent space can't keeping colourfulness of normal maps.
    Now I think the best way should be blending, but it's will be a hard work.
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