[osg-users] Mapping texture coordinates to a portion of a large (.obj) model

[Isaac Wolf]

Hello all,

I am new to OSG, and I am having some difficulty understanding the steps required to complete this task.

Basically, I want to map an image to a portion of a .obj file I am loading in as a Node. I have the 3D position and indices of four points that I would like to use as UV coordinates for an incoming image.

My primary issue is that the .obj doesn't have texture coordinates in the first place. So I figured I could add the only 4 points I care about manually, and assign them as UV coordinates.

Is this possible? Or do you always need a 1 to 1 mapping for texture coordinates? In pseudo/osg inspired code, I'd image it would look something like the following. 

Say I had a Vec3 array of 4 points that sit on the surface of a model called points_of_concern, and a uv_array that is just  <0,0>, <0,1>, etc.


Code:

...
<Node> myNode= readNodeFile("model.obj");
Vec3 points_of_concern=[<2.3, 3.2, 3.1>, ....];
Vec2 uv_array= [<0,0>, <0,1>...];

myNode->setTexCoordinates(points_of_concern);
Texture2D myTex = readImageFile("image.png");
myTex->setTextureCoordinates(uv_array);

myNode->setTexture(myTex);




It seems like a simple task, but I did a lot of searching without any luck!

Thanks for your time!

Regards,
Isaac[/code]

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http://forum.openscenegraph.org/viewtopic.php?p=75136#75136