I just study directx9 for a few months by myself,and i've been puzzled by a problem that is how to set texture for a sphere for a long time.i want to create an real earth like that of nasa world wind.In fact,i have create an earth,but some coordinate of the texture is wrong,i guess i have used a wrong formula. I hope you could help me! Thank you !
well,i use directx9.0 and language is c#(2003).

Answered by MattEvans 473 in a post from

How are you drawing the sphere; are you generating the vertices and texture coordinates manually? What is the projection method of the world texture you're using? A projection like this is easy to map: ( http://arstechnica.com/reviews/4q00/macosx-pb1/images/earth-map-huge.jpg ), there are other projection types though.. Some of them are easy, …

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How are you drawing the sphere; are you generating the vertices and texture coordinates manually? What is the projection method of the world texture you're using? A projection like this is easy to map: ( http://arstechnica.com/reviews/4q00/macosx-pb1/images/earth-map-huge.jpg ), there are other projection types though.. Some of them are easy, some of them not so easy.

You say you're having some problems with some of the coords, that implies to me that you've got it working for the most part, what exactly are the problems though? Is it mostly textured correctly, but with one line of faces where the texture seems really dense ( possibly across the point where the texture joins between 0 and 1 where it 'should' horizontally wrap in texture space )...? I had that problem myself for a while, in OpenGL. Turns out it was because I was re-using point structures, where the vertex would be shared but the texcoord isn't always shared, and that was causing the texture to wrap between 1-dx and 0... which meant I got a whole 0 to ~1 texture segment, backwards, within one column of faces... Easy to solve; double up the last column of vertices so that 1-dx spans to 1; or treat every compound point as unique..

Anyway, be a bit more specific, and I can try and be more helpful.