1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
|
/*
* 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 Unparametrized Surfaces on the GPU"
* Morten S. Mikkelsen, 2010 */
surface node_bump(
float SampleCenter = 0.0,
float SampleX = 0.0,
float SampleY = 0.0,
output normal Normal = N)
{
float dx = SampleX - SampleCenter;
float dy = SampleY - SampleCenter;
vector dPdx = Dx(P);
vector dPdy = Dy(P);
vector Rx = cross(dPdy, N);
vector Ry = cross(N, dPdx);
float det = dot(dPdx, Rx);
vector surfgrad = dx * Rx + dy * Ry;
surfgrad *= 0.1; /* todo: remove this factor */
Normal = normalize(abs(det) * N - sign(det) * surfgrad);
}
|