diff options
Diffstat (limited to 'intern/cycles/kernel/shaders/node_bump.osl')
| -rw-r--r-- | intern/cycles/kernel/shaders/node_bump.osl | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/intern/cycles/kernel/shaders/node_bump.osl b/intern/cycles/kernel/shaders/node_bump.osl new file mode 100644 index 00000000000..24db1b24458 --- /dev/null +++ b/intern/cycles/kernel/shaders/node_bump.osl @@ -0,0 +1,49 @@ +/* + * Copyright 2011, Blender Foundation. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +#include "stdosl.h" + +/* "Bump Mapping Unparameterized Surfaces on the GPU" + * Morten S. Mikkelsen, 2010 */ + +surface node_bump( + normal NormalIn = N, + float Strength = 0.0, + float SampleCenter = 0.0, + float SampleX = 0.0, + float SampleY = 0.0, + output normal Normal = N) +{ + /* get surface tangents from normal */ + vector dPdx = Dx(P); + vector dPdy = Dy(P); + + vector Rx = cross(dPdy, NormalIn); + vector Ry = cross(NormalIn, dPdx); + + /* compute surface gradient and determinant */ + float det = dot(dPdx, Rx); + vector surfgrad = (SampleX - SampleCenter) * Rx + (SampleY - SampleCenter) * Ry; + + surfgrad *= Strength; + float absdet = fabs(det); + + /* compute and output perturbed normal */ + Normal = normalize(absdet * NormalIn - sign(det) * surfgrad); +} + |