blender/intern/cycles/kernel/shaders/node_bump.osl
Mai Lavelle 92a2c49aab Cycles: Fix bump mapping to use object space when used with true displacement
Bump mapping was happening in world space while displacement happens in object
space, causing shading errors when displacement type was used with bump mapping.

To fix this the proper transforms are added to bump nodes. This is only done
for automatic bump mapping however, to avoid visual changes from other uses of
bump mapping. It would be nice to do this for all bump mapping to be consistent
but that will have to wait till we can break compatibility.

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D2191
2016-09-11 11:20:21 -04:00

69 lines
1.8 KiB
Plaintext

/*
* Copyright 2011-2013 Blender Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "stdosl.h"
/* "Bump Mapping Unparameterized Surfaces on the GPU"
* Morten S. Mikkelsen, 2010 */
surface node_bump(
int invert = 0,
int use_object_space = 0,
normal NormalIn = N,
float Strength = 0.1,
float Distance = 1.0,
float SampleCenter = 0.0,
float SampleX = 0.0,
float SampleY = 0.0,
output normal NormalOut = N)
{
point Ptmp = P;
normal Normal = NormalIn;
if (use_object_space) {
Ptmp = transform("object", Ptmp);
Normal = normalize(transform("object", Normal));
}
/* get surface tangents from normal */
vector dPdx = Dx(Ptmp);
vector dPdy = Dy(Ptmp);
vector Rx = cross(dPdy, Normal);
vector Ry = cross(Normal, dPdx);
/* compute surface gradient and determinant */
float det = dot(dPdx, Rx);
vector surfgrad = (SampleX - SampleCenter) * Rx + (SampleY - SampleCenter) * Ry;
float absdet = fabs(det);
float strength = max(Strength, 0.0);
float dist = Distance;
if (invert)
dist *= -1.0;
/* compute and output perturbed normal */
NormalOut = normalize(absdet * Normal - dist * sign(det) * surfgrad);
NormalOut = normalize(strength * NormalOut + (1.0 - strength) * Normal);
if (use_object_space) {
NormalOut = normalize(transform("object", "world", NormalOut));
}
}