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/* SPDX-License-Identifier: Apache-2.0
* Copyright 2011-2022 Blender Foundation */
#include "stdcycles.h"
shader node_normal_map(float Strength = 1.0,
color Color = color(0.5, 0.5, 1.0),
string space = "tangent",
string attr_name = "geom:tangent",
string attr_sign_name = "geom:tangent_sign",
output normal Normal = N)
{
color mcolor = 2.0 * color(Color[0] - 0.5, Color[1] - 0.5, Color[2] - 0.5);
int is_backfacing = backfacing();
if (space == "tangent") {
vector tangent;
vector ninterp;
float tangent_sign;
float is_smooth = 0.0;
getattribute("geom:is_smooth", is_smooth);
if (!is_smooth) {
ninterp = normalize(transform("world", "object", Ng));
/* the normal is already inverted, which is too soon for the math here */
if (is_backfacing) {
ninterp = -ninterp;
}
}
// get _unnormalized_ interpolated normal and tangent
if (getattribute(attr_name, tangent) && getattribute(attr_sign_name, tangent_sign) &&
(!is_smooth || getattribute("geom:normal_map_normal", ninterp))) {
// apply normal map
vector B = tangent_sign * cross(ninterp, tangent);
Normal = normalize(mcolor[0] * tangent + mcolor[1] * B + mcolor[2] * ninterp);
// transform to world space
Normal = normalize(transform("object", "world", Normal));
}
else {
Normal = normal(0, 0, 0);
}
}
else if (space == "object") {
Normal = normalize(transform("object", "world", vector(mcolor)));
}
else if (space == "world") {
Normal = normalize(vector(mcolor));
}
else if (space == "blender_object") {
/* strange blender convention */
mcolor[1] = -mcolor[1];
mcolor[2] = -mcolor[2];
Normal = normalize(transform("object", "world", vector(mcolor)));
}
else if (space == "blender_world") {
/* strange blender convention */
mcolor[1] = -mcolor[1];
mcolor[2] = -mcolor[2];
Normal = normalize(vector(mcolor));
}
/* invert normal for backfacing polygons */
if (is_backfacing) {
Normal = -Normal;
}
if (Strength != 1.0)
Normal = normalize(N + (Normal - N) * max(Strength, 0.0));
}
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