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WIP: renderer: compute normalmap from heightmap when missing normalmap, aka bumpmap #258

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WIP: renderer: compute normalmap from heightmap when missing normalmap, aka bumpmap #258

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11 changes: 11 additions & 0 deletions src/engine/renderer/gl_shader.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -573,6 +573,11 @@ static std::string GenEngineConstants() {
AddConst( str, "MAX_GLSL_BONES", 4 );
}

if ( r_sobelFiltering->integer )
{
AddDefine( str, "r_sobelFiltering", 1 );
}

if ( r_wrapAroundLighting->value )
AddConst( str, "r_WrapAroundLighting", r_wrapAroundLighting->value );

Expand Down Expand Up @@ -1496,6 +1501,7 @@ GLShader_lightMapping::GLShader_lightMapping( GLShaderManager *manager ) :
GLCompileMacro_USE_LIGHT_MAPPING( this ),
GLCompileMacro_USE_DELUXE_MAPPING( this ),
GLCompileMacro_USE_HEIGHTMAP_IN_NORMALMAP( this ),
GLCompileMacro_USE_NORMALMAP_FROM_HEIGHTMAP( this ),
GLCompileMacro_USE_PARALLAX_MAPPING( this ),
GLCompileMacro_USE_REFLECTIVE_SPECULAR( this ),
GLCompileMacro_USE_PHYSICAL_SHADING( this )
Expand Down Expand Up @@ -1560,6 +1566,7 @@ GLShader_forwardLighting_omniXYZ::GLShader_forwardLighting_omniXYZ( GLShaderMana
GLCompileMacro_USE_VERTEX_SKINNING( this ),
GLCompileMacro_USE_VERTEX_ANIMATION( this ),
GLCompileMacro_USE_HEIGHTMAP_IN_NORMALMAP( this ),
GLCompileMacro_USE_NORMALMAP_FROM_HEIGHTMAP( this ),
GLCompileMacro_USE_PARALLAX_MAPPING( this ),
GLCompileMacro_USE_SHADOWING( this )
{
Expand Down Expand Up @@ -1620,6 +1627,7 @@ GLShader_forwardLighting_projXYZ::GLShader_forwardLighting_projXYZ( GLShaderMana
GLCompileMacro_USE_VERTEX_SKINNING( this ),
GLCompileMacro_USE_VERTEX_ANIMATION( this ),
GLCompileMacro_USE_HEIGHTMAP_IN_NORMALMAP( this ),
GLCompileMacro_USE_NORMALMAP_FROM_HEIGHTMAP( this ),
GLCompileMacro_USE_PARALLAX_MAPPING( this ),
GLCompileMacro_USE_SHADOWING( this )
{
Expand Down Expand Up @@ -1683,6 +1691,7 @@ GLShader_forwardLighting_directionalSun::GLShader_forwardLighting_directionalSun
GLCompileMacro_USE_VERTEX_SKINNING( this ),
GLCompileMacro_USE_VERTEX_ANIMATION( this ),
GLCompileMacro_USE_HEIGHTMAP_IN_NORMALMAP( this ),
GLCompileMacro_USE_NORMALMAP_FROM_HEIGHTMAP( this ),
GLCompileMacro_USE_PARALLAX_MAPPING( this ),
GLCompileMacro_USE_SHADOWING( this )
{
Expand Down Expand Up @@ -1767,6 +1776,7 @@ GLShader_reflection::GLShader_reflection( GLShaderManager *manager ):
GLCompileMacro_USE_VERTEX_SKINNING( this ),
GLCompileMacro_USE_VERTEX_ANIMATION( this ),
GLCompileMacro_USE_HEIGHTMAP_IN_NORMALMAP( this ),
GLCompileMacro_USE_NORMALMAP_FROM_HEIGHTMAP( this ),
GLCompileMacro_USE_PARALLAX_MAPPING( this )
{
}
Expand Down Expand Up @@ -2035,6 +2045,7 @@ GLShader_liquid::GLShader_liquid( GLShaderManager *manager ) :
u_LightGridOrigin( this ),
u_LightGridScale( this ),
GLCompileMacro_USE_HEIGHTMAP_IN_NORMALMAP( this ),
GLCompileMacro_USE_NORMALMAP_FROM_HEIGHTMAP( this ),
GLCompileMacro_USE_PARALLAX_MAPPING( this )
{
}
Expand Down
34 changes: 33 additions & 1 deletion src/engine/renderer/gl_shader.h
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Original file line number Diff line number Diff line change
Expand Up @@ -30,7 +30,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
#define USE_UNIFORM_FIREWALL 1

// *INDENT-OFF*
static const unsigned int MAX_SHADER_MACROS = 9;
static const unsigned int MAX_SHADER_MACROS = 10;
static const unsigned int GL_SHADER_VERSION = 3;

class ShaderException : public std::runtime_error
Expand Down Expand Up @@ -787,6 +787,7 @@ class GLCompileMacro
USE_LIGHT_MAPPING,
USE_DELUXE_MAPPING,
USE_HEIGHTMAP_IN_NORMALMAP,
USE_NORMALMAP_FROM_HEIGHTMAP,
USE_PARALLAX_MAPPING,
USE_REFLECTIVE_SPECULAR,
USE_SHADOWING,
Expand Down Expand Up @@ -1087,6 +1088,31 @@ class GLCompileMacro_USE_HEIGHTMAP_IN_NORMALMAP :
}
};

class GLCompileMacro_USE_NORMALMAP_FROM_HEIGHTMAP :
GLCompileMacro
{
public:
GLCompileMacro_USE_NORMALMAP_FROM_HEIGHTMAP( GLShader *shader ) :
GLCompileMacro( shader )
{
}

const char *GetName() const
{
return "USE_NORMALMAP_FROM_HEIGHTMAP";
}

EGLCompileMacro GetType() const
{
return EGLCompileMacro::USE_NORMALMAP_FROM_HEIGHTMAP;
}

void SetNormalMapFromHeightMap( bool enable )
{
SetMacro( enable );
}
};

class GLCompileMacro_USE_PARALLAX_MAPPING :
GLCompileMacro
{
Expand Down Expand Up @@ -2245,6 +2271,7 @@ class GLShader_lightMapping :
public GLCompileMacro_USE_LIGHT_MAPPING,
public GLCompileMacro_USE_DELUXE_MAPPING,
public GLCompileMacro_USE_HEIGHTMAP_IN_NORMALMAP,
public GLCompileMacro_USE_NORMALMAP_FROM_HEIGHTMAP,
public GLCompileMacro_USE_PARALLAX_MAPPING,
public GLCompileMacro_USE_REFLECTIVE_SPECULAR,
public GLCompileMacro_USE_PHYSICAL_SHADING
Expand Down Expand Up @@ -2284,6 +2311,7 @@ class GLShader_forwardLighting_omniXYZ :
public GLCompileMacro_USE_VERTEX_SKINNING,
public GLCompileMacro_USE_VERTEX_ANIMATION,
public GLCompileMacro_USE_HEIGHTMAP_IN_NORMALMAP,
public GLCompileMacro_USE_NORMALMAP_FROM_HEIGHTMAP,
public GLCompileMacro_USE_PARALLAX_MAPPING,
public GLCompileMacro_USE_SHADOWING //,
{
Expand Down Expand Up @@ -2323,6 +2351,7 @@ class GLShader_forwardLighting_projXYZ :
public GLCompileMacro_USE_VERTEX_SKINNING,
public GLCompileMacro_USE_VERTEX_ANIMATION,
public GLCompileMacro_USE_HEIGHTMAP_IN_NORMALMAP,
public GLCompileMacro_USE_NORMALMAP_FROM_HEIGHTMAP,
public GLCompileMacro_USE_PARALLAX_MAPPING,
public GLCompileMacro_USE_SHADOWING //,
{
Expand Down Expand Up @@ -2364,6 +2393,7 @@ class GLShader_forwardLighting_directionalSun :
public GLCompileMacro_USE_VERTEX_SKINNING,
public GLCompileMacro_USE_VERTEX_ANIMATION,
public GLCompileMacro_USE_HEIGHTMAP_IN_NORMALMAP,
public GLCompileMacro_USE_NORMALMAP_FROM_HEIGHTMAP,
public GLCompileMacro_USE_PARALLAX_MAPPING,
public GLCompileMacro_USE_SHADOWING //,
{
Expand Down Expand Up @@ -2413,6 +2443,7 @@ class GLShader_reflection :
public GLCompileMacro_USE_VERTEX_SKINNING,
public GLCompileMacro_USE_VERTEX_ANIMATION,
public GLCompileMacro_USE_HEIGHTMAP_IN_NORMALMAP,
public GLCompileMacro_USE_NORMALMAP_FROM_HEIGHTMAP,
public GLCompileMacro_USE_PARALLAX_MAPPING
{
public:
Expand Down Expand Up @@ -2620,6 +2651,7 @@ class GLShader_liquid :
public u_LightGridOrigin,
public u_LightGridScale,
public GLCompileMacro_USE_HEIGHTMAP_IN_NORMALMAP,
public GLCompileMacro_USE_NORMALMAP_FROM_HEIGHTMAP,
public GLCompileMacro_USE_PARALLAX_MAPPING
{
public:
Expand Down
175 changes: 166 additions & 9 deletions src/engine/renderer/glsl_source/reliefMapping_fp.glsl
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Original file line number Diff line number Diff line change
Expand Up @@ -29,24 +29,181 @@ uniform sampler2D u_NormalMap;
uniform vec3 u_NormalScale;
#endif // r_normalMapping

#if defined(USE_PARALLAX_MAPPING)
#if !defined(USE_HEIGHTMAP_IN_NORMALMAP)
#if (defined(USE_PARALLAX_MAPPING) && !defined(USE_HEIGHTMAP_IN_NORMALMAP)) || defined(USE_NORMALMAP_FROM_HEIGHTMAP)
uniform sampler2D u_HeightMap;
#endif // !USE_HEIGHTMAP_IN_NORMALMAP
#endif // (USE_PARALLAX_MAPPING && !USE_HEIGHTMAP_IN_NORMALMAP) || USE_NORMALMAP_FROM_HEIGHTMAP

#if defined(USE_PARALLAX_MAPPING)
uniform float u_ParallaxDepthScale;
uniform float u_ParallaxOffsetBias;
#endif // USE_PARALLAX_MAPPING

#if defined(USE_NORMALMAP_FROM_HEIGHTMAP)
vec3 NormalFromHeightMap(vec2 texNormal)
{
vec3 normal;

/* Major inspiration was this post by jollyjeffers:
https://www.gamedev.net/forums/topic/475213-generate-normal-map-from-heightmap-algorithm/#post_4117038

and this Wikipedia article:
https://en.wikipedia.org/wiki/Sobel_operator

Various people recommends doing abs() on sample read in case of float image format:
http://www.catalinzima.com/2008/01/converting-displacement-maps-into-normal-maps/
https://community.khronos.org/t/heightmap-to-normalmap/58862

Or report issues by not doing it:
https://gamedev.stackexchange.com/questions/165575/calculating-normal-map-from-height-map-using-sobel-operator

Other people say texture2D clamps it but it's safer to do this.
*/

// Get texel size
vec2 texelSize = 1.0 / vec2(textureSize(u_HeightMap, 0));

#if defined(r_sobelFiltering)
/* Useful things to know:
- It's required to get height samples (S) surrounding the current texel (T) to do a sobel filter:

S S S
S T S
S S S

- Sobel X kernel is:

[ 1 0 -1 ]
[ 2 0 -2 ]
[ 1 0 -1 ]

See https://en.wikipedia.org/wiki/Sobel_operator#Formulation

- Sobel Y kernel is:

[ 1 2 1 ]
[ 0 0 0 ]
[ -1 -2 -1 ]

Which is the rotated sobel X kernel.

- Tangent space normals are +Z.
*/

ivec3 offsets;
mat3 xCoords;
mat3 yCoords;
mat3 heights;
mat3 sobel;

// Components will be computed by accumulating values.
normal = vec3(0.0, 0.0, 0.0);

// Set offsets:
offsets = ivec3(-1, 0, 1);

// Set sobel X kernel (beware, line is column with this notation):
sobel[0] = vec3( 1.0, 2.0, 1.0);
sobel[1] = vec3( 0.0, 0.0, 0.0);
sobel[2] = vec3(-1.0, -2.0, -1.0);

for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 3; j++)
{
if (i != 1 || j != 1)
{
// Compute coordinates:
xCoords[i][j] = texNormal.x + texelSize.x * offsets[i];
yCoords[i][j] = texNormal.y + texelSize.y * offsets[j];

// Get surrounding samples:
heights[i][j] = abs(texture2D(u_HeightMap, vec2(xCoords[i][j], yCoords[i][j])).r);

if (i != 1)
{
// Sobel computation for X component (use the X sobel kernel):
normal.x += heights[i][j] * sobel[i][j];
}

if (j != 1)
{
// Sobel computation for Y component (use the rotated X sobel kernel as Y one):
normal.y += heights[i][j] * sobel[j][i];
}
}
}
}

/* Reconstruct Z component while making sure to not take the square root
of a negative number. That may occur because of compression artifacts.

Xonotic texture known to produce black normalmap artifacts when doing
Z reconstruction from X and Y computed from jpg heightmap:
textures/map_glowplant/sand_bump
*/

normal.z = sqrt(max(0.0, 1.0 - dot(normal.xy, normal.xy)));

normal.xy = 2.0 * normal.xy;
#else // !r_sobelFiltering
/* Useful thing to know:
- Only three samples are required to determine two vectors
they would be used to generate the normal at this texel:

T S
S

The texel itself is used as sample.
*/

vec2 hOffsets;
vec2 vOffsets;
vec2 hCoords;
vec2 vCoords;
vec3 heights;
vec3 xVector;
vec3 yVector;

// Set horizontal and vertical offsets:
hOffsets = vec2(texelSize.x, 0.0);
vOffsets = vec2(0.0, texelSize.y);

// Compute coordinates:
hCoords = vec2(texNormal.x + hOffsets.x, texNormal.y + hOffsets.y);
vCoords = vec2(texNormal.x + vOffsets.x, texNormal.y + vOffsets.y);

// Get samples:
heights.x = texture2D(u_HeightMap, texNormal).r; // No offset.
heights.y = texture2D(u_HeightMap, hCoords).r;
heights.z = texture2D(u_HeightMap, vCoords).r;

xVector = vec3(hOffsets.x, vOffsets.x, heights.y - heights.x);
yVector = vec3(hOffsets.y, vOffsets.y, heights.z - heights.x);

normal = cross(xVector, yVector);
#endif // !r_sobelFiltering

return normal;
}
#endif // USE_NORMALMAP_FROM_HEIGHTMAP

// compute normal in tangent space
vec3 NormalInTangentSpace(vec2 texNormal)
{
vec3 normal;

#if defined(r_normalMapping)
#if defined(USE_HEIGHTMAP_IN_NORMALMAP)
#if defined(USE_NORMALMAP_FROM_HEIGHTMAP)
normal = NormalFromHeightMap(texNormal);
#elif defined(USE_HEIGHTMAP_IN_NORMALMAP)
// alpha channel contains the height map so do not try to reconstruct normal map from it
normal = texture2D(u_NormalMap, texNormal).rgb;
normal = 2.0 * normal - 1.0;

// HACK: the GLSL code is currently assuming
// DirectX normal map format (+X -Y +Z)
// but engine is assuming the OpenGL way (+X +Y +Z)
normal.y *= -1;
#else // !USE_HEIGHTMAP_IN_NORMALMAP
// the Capcom trick abusing alpha channel of DXT1/5 formats to encode normal map
// https://github.com/DaemonEngine/Daemon/issues/183#issuecomment-473691252
Expand Down Expand Up @@ -74,6 +231,11 @@ vec3 NormalInTangentSpace(vec2 texNormal)
// This might happen with other formats too. So we must take care not to
// take the square root of a negative number here.
normal.z = sqrt(max(0, 1.0 - dot(normal.xy, normal.xy)));

// HACK: the GLSL code is currently assuming
// DirectX normal map format (+X -Y +Z)
// but engine is assuming the OpenGL way (+X +Y +Z)
normal.y *= -1;
#endif // !USE_HEIGHTMAP_IN_NORMALMAP
/* Disable normal map scaling when normal Z scale is set to zero.

Expand All @@ -87,11 +249,6 @@ vec3 NormalInTangentSpace(vec2 texNormal)
{
normal *= u_NormalScale;
}

// HACK: the GLSL code is currently assuming
// DirectX normal map format (+X -Y +Z)
// but engine is assuming the OpenGL way (+X +Y +Z)
normal.y *= -1;
#else // !r_normalMapping
// Flat normal map is {0.5, 0.5, 1.0} in [ 0.0, 1.0]
// which is stored as {0.0, 0.0, 1.0} in [-1.0, 1.0].
Expand Down
2 changes: 2 additions & 0 deletions src/engine/renderer/tr_init.cpp
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Expand Up @@ -171,6 +171,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
cvar_t *r_glowMapping;
cvar_t *r_reflectionMapping;

cvar_t *r_sobelFiltering;
cvar_t *r_wrapAroundLighting;
cvar_t *r_halfLambertLighting;
cvar_t *r_rimLighting;
Expand Down Expand Up @@ -1203,6 +1204,7 @@ ScreenshotCmd screenshotPNGRegistration("screenshotPNG", ssFormat_t::SSF_PNG, "p
r_glowMapping = ri.Cvar_Get( "r_glowMapping", "1", CVAR_LATCH );
r_reflectionMapping = ri.Cvar_Get( "r_reflectionMapping", "0", CVAR_CHEAT );

r_sobelFiltering = ri.Cvar_Get( "r_sobelFiltering", "1", CVAR_LATCH );
r_wrapAroundLighting = ri.Cvar_Get( "r_wrapAroundLighting", "0.7", CVAR_CHEAT | CVAR_LATCH );
r_halfLambertLighting = ri.Cvar_Get( "r_halfLambertLighting", "1", CVAR_CHEAT | CVAR_LATCH );
r_rimLighting = ri.Cvar_Get( "r_rimLighting", "0", CVAR_LATCH | CVAR_ARCHIVE );
Expand Down
2 changes: 2 additions & 0 deletions src/engine/renderer/tr_local.h
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Expand Up @@ -1143,6 +1143,7 @@ static inline void halfToFloat( const f16vec4_t in, vec4_t out )
bool hasNormalMap;
bool hasHeightMap;
bool isHeightMapInNormalMap;
bool isNormalMapFromHeightMap;
bool hasMaterialMap;
bool isMaterialPhysical;
bool hasGlowMap;
Expand Down Expand Up @@ -2895,6 +2896,7 @@ static inline void halfToFloat( const f16vec4_t in, vec4_t out )
extern cvar_t *r_glowMapping;
extern cvar_t *r_reflectionMapping;

extern cvar_t *r_sobelFiltering;
extern cvar_t *r_wrapAroundLighting;
extern cvar_t *r_halfLambertLighting;
extern cvar_t *r_rimLighting;
Expand Down
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