/usr/share/radiance/tmesh.cal is in radiance-materials 4R1+20120125-1.
This file is owned by root:root, with mode 0o644.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 | { RCSid: $Id: tmesh.cal,v 2.2 2004/03/11 23:16:01 greg Exp $ }
{
Interpolate triangle-mesh values using barycentric coordinates.
A1 = Major axis (0==X, 1==Y, 2==Z)
A2 through A10 = Surface normal perturbation matrix
or:
A2 through A7 = Lookup in 2-dimensional pattern or texture
}
{ Get dominant coordinates }
bu = select(arg(1)+1, Py, Pz, Px);
bv = select(arg(1)+1, Pz, Px, Py);
{ Compute variables }
v1 = bu*arg( 2) + bv*arg( 3) + arg( 4);
v2 = bu*arg( 5) + bv*arg( 6) + arg( 7);
v3 = bu*arg( 8) + bv*arg( 9) + arg(10);
{ Surface normal perturbation }
nf = 1/sqrt(v1*v1 + v2*v2 + v3*v3);
dx = v1*nf - Nx;
dy = v2*nf - Ny;
dz = v3*nf - Nz;
{ Tiled texture coordinates }
u = frac(v1);
v = frac(v2);
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