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umas

Problem with normals of triangle-strips

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umas    100
Hey guys,

I have some trouble to set the vertex-normals for a triangle-strip, which is stored within one big array.
At the end of each row, I draw 2 "dummy"-triangles to be able to jump to the beginning of the next row.
Which means, if I want to draw:
1--4--7
| / | / |
2--5--8
| / | / |
3--6--9
My ordering is 1,2,4,5,7,8,8,2,3,5,6,8,9.

When I don't use light and shading, everything looks fine. But when I turn on lightning, the normals come into play and I have a lot of stripes within the rendered surface. Has anybody an idea how I can avoid these stripes? Have I forgot to initialize something?

I have no idea - its the first time that I want to shade a rendered surface.

Thanks a lot for your help [img]http://public.gamedev.net//public/style_emoticons/default/smile.png[/img]


[code]
void initGL(){
...
glEnable(GL_TEXTURE_2D);
glEnable(GL_DEPTH_TEST);
GLfloat LightAmbient[]= { 0.5f, 0.5f, 0.5f, 1.0f };
GLfloat LightDiffuse[]= { 1.0f, 1.0f, 1.0f, 1.0f };
GLfloat LightPosition[]= { 0.0f, 800.0f, 2.0f, 1.0f };
glLightfv(GL_LIGHT0, GL_AMBIENT, LightAmbient);
glLightfv(GL_LIGHT0, GL_DIFFUSE, LightDiffuse);
glLightfv(GL_LIGHT0, GL_POSITION,LightPosition);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glColorMaterial(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE);
glEnable(GL_COLOR_MATERIAL);
glShadeModel(GL_SMOOTH);
...
}
[/code]


Here you can see the result...
[attachment=7969:terrain.png]

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tanzanite7    1410
Perhaps your normals are wrong. They, obviously, should not contradict what other adjacent triangles have at the same vertex (different strip).

Btw. Unrelated, but i mention anyway. Might want to use just indexed triangles - by my count, the days where strips were worth a damn are long gone (immho).

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umas    100
ok, thanks a lot...I will check my normals....

@triangle-strips: I know...and it was not my idea...but its part of a university-project and we have to use triangle strips :(

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