Textcoord? Channel?

Other Standards COLLADA
1

here a piece of mi collada file:


  <geometry id="Cylinder01-mesh" name="Cylinder01">
      <mesh>
        <source id="Cylinder01-mesh-positions">
          <float_array id="Cylinder01-mesh-positions-array" count="96">0 0 0 5 0 0 2.5 4.33013 0 -2.5 4.33013 0 -5 -0.000000 0 -2.5 -4.33013 0 2.5 -4.33013 0 5 0 12.5 2.5 4.33013 12.5 -2.5 4.33013 12.5 -5 -0.000000 12.5 -2.5 -4.33013 12.5 2.5 -4.33013 12.5 5 0 25 2.5 4.33013 25 -2.5 4.33013 25 -5 -0.000000 25 -2.5 -4.33013 25 2.5 -4.33013 25 5 0 37.5 2.5 4.33013 37.5 -2.5 4.33013 37.5 -5 -0.000000 37.5 -2.5 -4.33013 37.5 2.5 -4.33013 37.5 5 0 50 2.5 4.33013 50 -2.5 4.33013 50 -5 -0.000000 50 -2.5 -4.33013 50 2.5 -4.33013 50 0 0 50</float_array>
          <technique_common>
            <accessor source="#Cylinder01-mesh-positions-array" count="32" stride="3">
              <param name="X" type="float"/>
              <param name="Y" type="float"/>
              <param name="Z" type="float"/>
            </accessor>
          </technique_common>
        </source>
        <source id="Cylinder01-mesh-normals">
          <float_array id="Cylinder01-mesh-normals-array" count="132">0 0 -1 0 0 -1 0 0 -1 0 0 -1 0 0 -1 0 0 -1 0 0 -1 1 0 0 0.5 0.866025 0 1 0 0 0.5 0.866025 0 -0.5 0.866025 0 -0.5 0.866025 0 -1 0 0 -1 0 0 -0.5 -0.866025 0 -0.5 -0.866026 0 0.5 -0.866025 0 0.5 -0.866025 0 0.5 0.866025 0 1 0 0 -0.5 0.866025 0 -1 0 0 -0.5 -0.866025 0 0.5 -0.866025 0 0.5 0.866025 0 1 0 0 -0.5 0.866025 0 -1 0 0 -0.5 -0.866025 0 0.5 -0.866025 0 0.5 0.866025 0 1 0 0 -0.5 0.866025 0 -1 0 0 -0.5 -0.866026 0 0.5 -0.866025 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1</float_array>
          <technique_common>
            <accessor source="#Cylinder01-mesh-normals-array" count="44" stride="3">
              <param name="X" type="float"/>
              <param name="Y" type="float"/>
              <param name="Z" type="float"/>
            </accessor>
          </technique_common>
        </source>
        <source id="Cylinder01-mesh-map-channel1">
          <float_array id="Cylinder01-mesh-map-channel1-array" count="138">0.5 0 0 0.75 0 1 0.916667 0 1 0.083333 0 1 0.25 0 1 0.416667 0 1 0.583333 0 1 0.75 0.25 1 0.916667 0.25 1 0.083333 0.25 1 0.25 0.25 1 0.416667 0.25 1 0.583333 0.25 1 0.75 0.5 1 0.916667 0.5 1 0.083333 0.5 1 0.25 0.5 1 0.416667 0.5 1 0.583333 0.5 1 0.75 0.75 1 0.916667 0.75 1 0.083333 0.75 1 0.25 0.75 1 0.416667 0.75 1 0.583333 0.75 1 0.75 1 1 0.916667 1 1 0.083333 1 1 0.25 1 1 0.416667 1 1 0.583333 1 1 0.5 1 0 -0.083333 0 1 -0.083333 0 1 -0.083333 0.25 1 -0.083333 0 1 -0.083333 0.25 1 -0.083333 0.5 1 -0.083333 0.25 1 -0.083333 0.5 1 -0.083333 0.75 1 -0.083333 0.5 1 -0.083333 0.75 1 -0.083333 1 1 -0.083333 0.75 1 -0.083333 1 1</float_array>
          <technique_common>
            <accessor source="#Cylinder01-mesh-map-channel1-array" count="46" stride="3">
              <param name="S" type="float"/>
              <param name="T" type="float"/>
              <param name="P" type="float"/>
            </accessor>
          </technique_common>
        </source>
        <source id="Cylinder01-mesh-map-channel1-tangents">
          <float_array id="Cylinder01-mesh-map-channel1-tangents-array" count="21">0 0 1 0 1 0 -0.866025 0.5 0 -0.866025 -0.5 0 0 -1 0 0.866025 -0.5 0 0.866025 0.5 0</float_array>
          <technique_common>
            <accessor source="#Cylinder01-mesh-map-channel1-tangents-array" count="7" stride="3">
              <param name="X" type="float"/>
              <param name="Y" type="float"/>
              <param name="Z" type="float"/>
            </accessor>
          </technique_common>
        </source>
        <source id="Cylinder01-mesh-map-channel1-binormals">
          <float_array id="Cylinder01-mesh-map-channel1-binormals-array" count="6">1 0 0 0 0 1</float_array>
          <technique_common>
            <accessor source="#Cylinder01-mesh-map-channel1-binormals-array" count="2" stride="3">
              <param name="X" type="float"/>
              <param name="Y" type="float"/>
              <param name="Z" type="float"/>
            </accessor>
          </technique_common>
        </source>
        <vertices id="Cylinder01-mesh-vertices">
          <input semantic="POSITION" source="#Cylinder01-mesh-positions"/>
        </vertices>
        <triangles material="_2_-_Default" count="60">
          <input semantic="VERTEX" source="#Cylinder01-mesh-vertices" offset="0"/>
          <input semantic="NORMAL" source="#Cylinder01-mesh-normals" offset="1"/>
          <input semantic="TEXCOORD" source="#Cylinder01-mesh-map-channel1" offset="2" set="1"/>
          <input semantic="TEXTANGENT" source="#Cylinder01-mesh-map-channel1-tangents" offset="3" set="1"/>
          <input semantic="TEXBINORMAL" source="#Cylinder01-mesh-map-channel1-binormals" offset="4" set="1"/>..
0</p>
        </triangles>
      </mesh>
    </geometry>

what is this:
<source id=“Cylinder01-mesh-map-channel1”>
is a textcoord source?
<input semantic=“TEXCOORD” source="#Cylinder01-mesh-map-channel1" offset=“2” set=“1”/>
but the UV are 2(U and V) not 3!
WHy?
and there are 3:
<param name=“S” type=“float”/>
<param name=“T” type=“float”/>
<param name=“P” type=“float”/>
i’m not understand.
And…
What i do with the tangent and binormals?
Thanks.

2

You are correct in idetifying the ‘<source id=“Cylinder01-mesh-map-channel1”>’ as the texture coordinates. It appears your exporter is exporting 3D texture coordinates instead of 2D. You may find that if you are only using 2 dimensional textures you can ignore one of the dimensional parameters.

TEXTANGENT and TEXBINORMAL are data sets that can be used in performing rendering techniques such as bump mapping where tangents and bi-normals are required.

If you do not require any such feature, you can proabably ignore these two source elements when performing your rendering.

Remember however, that they cannot be overlooked in the triangle indices stride.
I.e.



 vertex normal texcoord tangent binormal vertex normal.... (etc.) </p>

Adam.