Texture coordinates reference frame.

I am quite new to Collada 1.4.1 but have learned enough to render 3D scenes with OpenTK using colours instead of textures. This is where I seem to be a little confused and perhaps missing the documentation on this issue. The example file I am using has a list of images which are used as the basis for mapping textures. In OpenGL (Mother of OpenTK) they tell you to map onto a standard unit square (0,0) -> (1,1) and with scaling you can map an n x m pixel image onto this. I realise Collada must be different as in this following fragment the S,T pair is out of this range:-

<source id="ID574">
<float_array id="ID577" count="196">8.783203299153387 -4.388240037266483 47.57835529915261 9.936521619708513 ... </float_array>
                        <accessor count="98" source="#ID577" stride="2">
                            <param name="S" type="float" />
                            <param name="T" type="float" />

Tracing through effects,effect_instances, materials and material_instances we finally end up with referencing in 2D mode a texture image:-

<image id="ID568">

The size of this image is 172 x 128 pixels (width x height)

Quite clearly the S,T coordinates do not seem to be applicable to refering to a unit square reference frame or the image reference frame directly as the negative coordinates suggest.

I would be most grateful if someone could direct me to how to link up the image to the texcoord S,T pairs as referenced in the Collada data files.

Many thanks
Gordon Pagan

Well I solved this problem…

I should have known as I have done this earlier. I forgot that OpenGL/OpenTK only likes textures which have images that have a width and a height in powers of 2 Collada has no restrictions and I forgot to address this critical conversion issue. Please avoid this situation at all costs.