Brecht Van Lommel
3e763d7e4d
the Bump node has a Normal input, so you can chain it after a Normal Map node. Note that normal mapping always has to be done first because it is tied to the particular mesh surface and tangents.
50 lines
1.5 KiB
Plaintext
50 lines
1.5 KiB
Plaintext
/*
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* Copyright 2011, Blender Foundation.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*/
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#include "stdosl.h"
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/* "Bump Mapping Unparameterized Surfaces on the GPU"
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* Morten S. Mikkelsen, 2010 */
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surface node_bump(
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normal NormalIn = N,
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float Strength = 0.0,
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float SampleCenter = 0.0,
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float SampleX = 0.0,
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float SampleY = 0.0,
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output normal NormalOut = N)
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{
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/* get surface tangents from normal */
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vector dPdx = Dx(P);
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vector dPdy = Dy(P);
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vector Rx = cross(dPdy, NormalIn);
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vector Ry = cross(NormalIn, dPdx);
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/* compute surface gradient and determinant */
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float det = dot(dPdx, Rx);
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vector surfgrad = (SampleX - SampleCenter) * Rx + (SampleY - SampleCenter) * Ry;
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surfgrad *= Strength;
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float absdet = fabs(det);
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/* compute and output perturbed normal */
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NormalOut = normalize(absdet * NormalIn - sign(det) * surfgrad);
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}
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