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greg |
2.1 |
{ RCSid: $Id$ } |
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{ |
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Interpolate triangle-mesh values using barycentric coordinates. |
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A1 = Major axis (0==X, 1==Y, 2==Z) |
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A2 through A10 = Surface normal perturbation matrix |
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or: |
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A2 through A7 = Lookup in 2-dimensional pattern or texture |
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} |
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{ Get dominant coordinates } |
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bu = select(arg(1)+1, Py, Pz, Px); |
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bv = select(arg(1)+1, Pz, Px, Py); |
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{ Compute variables } |
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v1 = bu*arg( 2) + bv*arg( 3) + arg( 4); |
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v2 = bu*arg( 5) + bv*arg( 6) + arg( 7); |
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v3 = bu*arg( 8) + bv*arg( 9) + arg(10); |
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{ Surface normal perturbation } |
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nf = 1/sqrt(v1*v1 + v2*v2 + v3*v3); |
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dx = v1*nf - Nx; |
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dy = v2*nf - Ny; |
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dz = v3*nf - Nz; |
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{ Lookup table index } |
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u = v1; |
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v = v2; |