surface normal

(redirected from Normal vector)

surface normal

In 3D graphics, an imaginary line that is perpendicular to the surface of a polygon. It may be computed at the vertex of a triangle, in which case it is the average of all the vertices of adjoining triangles. Or, it may be computed for each pixel in the triangle as in Phong shading. Surface normals are used to derive the reflectivity of a light source shining onto an object. See tessellation, triangle, Phong shading and Gouraud shading.
References in periodicals archive ?
Thus, after allocation of the points forming cutting line using (2), and obtaining their spatial coordinates it is necessary to solve a problem of calculation of normal vector to surface of parts in all points of this line.
i]) is calculated by the inner product of the unit direction vector (i) of the incidence photons and the unit normal vector ([[vector].
i] in the normal direction of the surface is obtained by projecting following a unitary normal vector (shown as [[vector].
We shall assume that M is oriented (so that a unit normal vector field [xi] is defined on the whole M)and that the type number k(x) is greater than 0 everywhere on M.
w] is the unit normal vector directed into the wall, and [[[vector].
m]), the normal vector of reflection (N), the ideal reflection vector ([R.
g] is the normal vector for cutter surfaces of segment a; Eq.
Where denotes the dot product and W the (not necessarily normalized) normal vector to the hyper plane.
For an affine hyperplane H and a normal vector direction, let [H.
y]) is the solution of the boundary of the normal vector field, [OMEGA] is the solution domain, [partial derivative][OMEGA] is the boundary outward normal vector.
An additional condition, verified in the described procedure, analyzes the values of angle deviations of every normal vector of the respective triangles, from the direction of the resultant vector.