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{ RCSid: $Id: source.cal,v 2.9 2003/02/22 02:07:23 greg Exp $ } |
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{ |
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Source distribution coordinates (degrees). |
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|
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Theta is measured from the negative z-axis. |
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Phi is measured from the positive x-axis (0 degrees) |
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towards the positive y-axis (90 degrees). |
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|
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srcB_vert and srcB_horiz are angles |
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used in type B photometry. |
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|
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boxcorr function corrects for distribution modeled |
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with a rectangular box. lboxcorr provides a more |
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accurate calculation for nearby surfaces, but requires |
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that the source box be centered at the origin. |
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The dimensions of the box, which must be aligned with |
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the x,y,z axes, are given in meters regardless of the |
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units being used in the scene file. |
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|
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cylcorr function provides the same correction for a |
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cylinder whose central axis is aligned with the Z-axis. |
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|
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A1 - optional multipier |
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A2,A3,A4 - X,Y,Z dimensions of axis-aligned box (in meters!) |
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or |
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A2,A3 - diameter and height of Z-aligned cylinder (meters) |
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} |
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{ local definitions } |
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boxprojection = abs(Dx)*A3*A4 + abs(Dy)*A2*A4 + abs(Dz)*A2*A3; |
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lboxprojection = ( noneg(abs(Px-Dx*Ts)-A2/2)*A3*A4 + |
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noneg(abs(Py-Dy*Ts)-A3/2)*A2*A4 + |
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noneg(abs(Pz-Dz*Ts)-A4/2)*A2*A3 ) / Ts; |
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cylprojection = A2*A3*sqrt(1-Dz*Dz) + PI/4*A2*A2*abs(Dz); |
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|
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flatcorr(v) = corr(v) / Rdot; { correction for flat sources } |
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corr(v) = if(AC-.5, A1*v, v); { multiplier correction } |
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boxcorr(v) = A1 * v / boxprojection; { correction for emitting box } |
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lboxcorr(v) = A1 * v / lboxprojection; { local box correction } |
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cylcorr(v) = A1 * v / cylprojection; { cylinder correction } |
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|
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src_theta = Acos(Dz) / DEGREE; { 0-180 } |
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src_phi = mod( Atan2(-Dy, -Dx) / DEGREE, 360 ); { 0-360 } |
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{ bilateral symmetry } |
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src_phi2 = tri( src_phi, 180 ); { 0-180 } |
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{ quadrilateral symmetry } |
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src_phi4 = tri( src_phi, 90 ); { 0-90 } |
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|
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{ Type B photometry coordinates } |
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srcB_vert = atan2( -Dx, Dz ) / DEGREE; |
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srcB_horiz = atan2( Dy, Dz ) / DEGREE; |
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{ w/ symmetry } |
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srcB_vert2 = abs( srcB_vert ); |
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srcB_horiz2 = abs( srcB_horiz ); |
