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how to calculate vertex normal?

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Can anyone help me on how to calculate the vertex normal, for instance if i want to calculate the vertex normal of each vertex of a cylinder, also if one can provide me some good articles/tutorials regarding lights in direct3d, as i have understood it is one of the toughest topics in game programming, it would be very helpful.

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Say your cylinder is y-axis-aligned (y pointing up), I mean, with the two disks being parallel to the xz-plane (so their surface normals point up/down), and the main axis of the cylinder going through the point (0,0,0), then the normal for each vertex is just it's position on the xz-plane, and then normalised: n = v(x,0,z) / length (v (x,0,z)). Plugging y into that formula gives you spherical normals.

If you are creating the cylinder using sin/cos methods, then make it on the fly like:

normal.x = cos (angle)
normal.z = sin (angle)
normal.y = 0
x = radius * normal.x
y = <some height>
z = radius * normal.z



The normals of the disks are then (0,1,0) and (0,-1,0).

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