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HDR: W3.0 water shader - initial implementation

Implement a simple water shader for HDR.

Largely created from the non-HDR WS3.0 water shader,
but only generating a fragment normal.

Notes:
- Water color is a constant in the shader, and set by eye
  only.
- foam etc is not yet implemented.
- at very low altitudes the shader breaks down somewhat.
This commit is contained in:
Stuart Buchanan 2024-02-24 17:09:51 +00:00
parent c0e1e31674
commit dda21aeae1
3 changed files with 330 additions and 5 deletions

View file

@ -1932,6 +1932,7 @@
<vertex-shader>Shaders/HDR/ws30.vert</vertex-shader>
<vertex-shader>Shaders/HDR/logarithmic_depth.glsl</vertex-shader>
<fragment-shader>Shaders/HDR/ws30.frag</fragment-shader>
<fragment-shader>Shaders/HDR/water.glsl</fragment-shader>
<fragment-shader>Shaders/HDR/logarithmic_depth.glsl</fragment-shader>
<fragment-shader>Shaders/HDR/gbuffer_pack.glsl</fragment-shader>
<fragment-shader>Shaders/HDR/normal_encoding.glsl</fragment-shader>
@ -1953,6 +1954,67 @@
<type>sampler-2d</type>
<value type="int">6</value>
</uniform>
<uniform>
<name>coastline</name>
<type>sampler-2d</type>
<value type="int">7</value>
</uniform>
<uniform>
<name>WindE</name>
<type>float</type>
<value>
<use>windE</use>
</value>
</uniform>
<uniform>
<name>WindN</name>
<type>float</type>
<value>
<use>windN</use>
</value>
</uniform>
<uniform>
<name>WaveFreq</name>
<type>float</type>
<value>
<use>WaveFreq</use>
</value>
</uniform>
<uniform>
<name>WaveAmp</name>
<type>float</type>
<value>
<use>WaveAmp</use>
</value>
</uniform>
<uniform>
<name>WaveSharp</name>
<type>float</type>
<value>
<use>WaveSharp</use>
</value>
</uniform>
<uniform>
<name>WaveAngle</name>
<type>float</type>
<value>
<use>WaveAngle</use>
</value>
</uniform>
<uniform>
<name>WaveFactor</name>
<type>float</type>
<value>
<use>WaveFactor</use>
</value>
</uniform>
<uniform>
<name>WaveDAngle</name>
<type>float</type>
<value>
<use>WaveDAngle</use>
</value>
</uniform>
</pass>
</technique>

247
Shaders/HDR/water.glsl Normal file
View file

@ -0,0 +1,247 @@
// SPDX-FileCopyrightText: (C) 2024 Stuart Buchanan stuart13@gmail.com
// SPDX-License-Identifier: GPL-2.0-or-later
// Helper functions for WS30 HDR water implementation
#version 330 core
// Hardcoded indexes into the texture atlas
const int ATLAS_INDEX_WATER = 0;
const int ATLAS_INDEX_WATER_REFLECTION = 1;
const int ATLAS_INDEX_WAVES_VERT10_NM = 2;
const int ATLAS_INDEX_WATER_SINE_NMAP = 3;
const int ATLAS_INDEX_WATER_REFLECTION_GREY = 4;
const int ATLAS_INDEX_SEA_FOAM = 5;
const int ATLAS_INDEX_PERLIN_NOISE_NM = 6;
const int ATLAS_INDEX_OCEAN_DEPTH = 7;
const int ATLAS_INDEX_GLOBAL_COLORS = 8;
const int ATLAS_INDEX_PACKICE_OVERLAY = 9;
// WS30 uniforms
uniform sampler2DArray atlas;
uniform float fg_tileWidth;
uniform float fg_tileHeight;
// Water.eff uniforms
uniform float osg_SimulationTime;
uniform float WindN;
uniform float WindE;
uniform float WaveFreq;
uniform float WaveAmp;
uniform float WaveSharp;
uniform float WaveAngle;
uniform float WaveFactor;
/////// functions /////////
void rotationmatrix(in float angle, out mat4 rotmat)
{
rotmat = mat4( cos( angle ), -sin( angle ), 0.0, 0.0,
sin( angle ), cos( angle ), 0.0, 0.0,
0.0 , 0.0 , 1.0, 0.0,
0.0 , 0.0 , 0.0, 1.0 );
}
// wave functions ///////////////////////
struct Wave {
float freq; // 2*PI / wavelength
float amp; // amplitude
float phase; // speed * 2*PI / wavelength
vec2 dir;
};
Wave wave0 = Wave(1.0, 1.0, 0.5, vec2(0.97, 0.25));
Wave wave1 = Wave(2.0, 0.5, 1.3, vec2(0.97, -0.25));
Wave wave2 = Wave(1.0, 1.0, 0.6, vec2(0.95, -0.3));
Wave wave3 = Wave(2.0, 0.5, 1.4, vec2(0.99, 0.1));
float evaluateWave(in Wave w, in vec2 pos, in float t) {
return w.amp * sin( dot(w.dir, pos) * w.freq + t * w.phase);
}
// derivative of wave function
float evaluateWaveDeriv(in Wave w, in vec2 pos, in float t) {
return w.freq * w.amp * cos( dot(w.dir, pos)*w.freq + t*w.phase);
}
// sharp wave functions
float evaluateWaveSharp(in Wave w, in vec2 pos, in float t, in float k) {
return w.amp * pow(sin( dot(w.dir, pos)*w.freq + t*w.phase)* 0.5 + 0.5 , k);
}
float evaluateWaveDerivSharp(in Wave w, in vec2 pos, in float t, in float k) {
return k*w.freq*w.amp * pow(sin( dot(w.dir, pos)*w.freq + t*w.phase)* 0.5 + 0.5 , k - 1) * cos( dot(w.dir, pos)*w.freq + t*w.phase);
}
void sumWaves(in float angle, in float dangle, in float windScale, in float factor, in vec4 waterTex1, out float ddx, float ddy) {
mat4 RotationMatrix;
float deriv;
vec4 P = waterTex1 * 1024;
rotationmatrix(radians(angle + dangle * windScale + 0.6 * sin(P.x * factor)), RotationMatrix);
P *= RotationMatrix;
P.y += evaluateWave(wave0, P.xz, osg_SimulationTime);
deriv = evaluateWaveDeriv(wave0, P.xz, osg_SimulationTime );
ddx = deriv * wave0.dir.x;
ddy = deriv * wave0.dir.y;
P.y += evaluateWaveSharp(wave2, P.xz, osg_SimulationTime, WaveSharp);
deriv = evaluateWaveDerivSharp(wave2, P.xz, osg_SimulationTime, WaveSharp);
ddx += deriv * wave2.dir.x;
ddy += deriv * wave2.dir.y;
}
vec3 generateWaterNormal(in vec2 texCoords)
{
float tileScale = 1 / (fg_tileHeight + fg_tileWidth) / 2.0;
vec4 sca = vec4(0.005, 0.005, 0.005, 0.005) * tileScale;
vec4 sca2 = vec4(0.02, 0.02, 0.02, 0.02) * tileScale;
vec4 tscale = vec4(0.25, 0.25, 0.25, 0.25) / 10000.0 * tileScale;
vec3 Normal = vec3 (0.0, 0.0, 1.0);
const float water_shininess = 240.0;
float windEffect = sqrt( WindE*WindE + WindN*WindN ) * 0.6; //wind speed in kt
float windScale = 15.0/(3.0 + windEffect); //wave scale
float windEffect_low = 0.3 + 0.7 * smoothstep(0.0, 5.0, windEffect); //low windspeed wave filter
float waveRoughness = 0.01 + smoothstep(0.0, 40.0, windEffect); //wave roughness filter
vec4 t1 = vec4(0.0, osg_SimulationTime * 0.005217, 0.0, 0.0);
vec4 t2 = vec4(0.0, osg_SimulationTime * -0.0012, 0.0, 0.0);
float Angle;
float windFactor = sqrt(WindE * WindE + WindN * WindN) * 0.05;
if (WindN == 0.0 && WindE == 0.0) {
Angle = 0.0;
} else {
Angle = atan(-WindN, WindE) - atan(1.0);
}
mat4 RotationMatrix;
rotationmatrix(Angle, RotationMatrix);
vec4 waterTex1 = vec4(texCoords.s, texCoords.t, 0.0, 0.0) * RotationMatrix - t1 * windFactor;
rotationmatrix(Angle, RotationMatrix);
vec4 waterTex2 = vec4(texCoords.s, texCoords.t, 0.0, 0.0) * RotationMatrix - t2 * windFactor;
float mixFactor = 0.2 + 0.02 * smoothstep(0.0, 50.0, windEffect);
mixFactor = clamp(mixFactor, 0.3, 0.8);
// sine waves
float ddx, ddx1, ddx2, ddx3, ddy, ddy1, ddy2, ddy3;
float angle;
ddx = 0.0, ddy = 0.0;
ddx1 = 0.0, ddy1 = 0.0;
ddx2 = 0.0, ddy2 = 0.0;
ddx3 = 0.0, ddy3 = 0.0;
angle = 0.0;
wave0.freq = WaveFreq ;
wave0.amp = WaveAmp;
wave0.dir = vec2 (0.0, 1.0); //vec2(cos(radians(angle)), sin(radians(angle)));
angle -= 45;
wave1.freq = WaveFreq * 2.0 ;
wave1.amp = WaveAmp * 1.25;
wave1.dir = vec2(0.70710, -0.7071); //vec2(cos(radians(angle)), sin(radians(angle)));
angle += 30;
wave2.freq = WaveFreq * 3.5;
wave2.amp = WaveAmp * 0.75;
wave2.dir = vec2(0.96592, -0.2588);// vec2(cos(radians(angle)), sin(radians(angle)));
angle -= 50;
wave3.freq = WaveFreq * 3.0 ;
wave3.amp = WaveAmp * 0.75;
wave3.dir = vec2(0.42261, -0.9063); //vec2(cos(radians(angle)), sin(radians(angle)));
// sum waves
sumWaves(WaveAngle, -1.5, windScale, WaveFactor, waterTex1, ddx, ddy);
sumWaves(WaveAngle, 1.5, windScale, WaveFactor, waterTex1, ddx1, ddy1);
//reset the waves
angle = 0.0;
float waveamp = WaveAmp * 0.75;
wave0.freq = WaveFreq ;
wave0.amp = waveamp;
wave0.dir = vec2 (0.0, 1.0); //vec2(cos(radians(angle)), sin(radians(angle)));
angle -= 20;
wave1.freq = WaveFreq * 2.0 ;
wave1.amp = waveamp * 1.25;
wave1.dir = vec2(0.93969, -0.34202);// vec2(cos(radians(angle)), sin(radians(angle)));
angle += 35;
wave2.freq = WaveFreq * 3.5;
wave2.amp = waveamp * 0.75;
wave2.dir = vec2(0.965925, 0.25881); //vec2(cos(radians(angle)), sin(radians(angle)));
angle -= 45;
wave3.freq = WaveFreq * 3.0 ;
wave3.amp = waveamp * 0.75;
wave3.dir = vec2(0.866025, -0.5); //vec2(cos(radians(angle)), sin(radians(angle)));
// end sine stuff
vec2 st = vec2(waterTex2 * tscale * windScale);
vec4 disdis = texture(atlas, vec3(st, ATLAS_INDEX_WATER_SINE_NMAP)) * 2.0 - 1.0;
//normalmaps
st = vec2(waterTex1 + disdis * sca2) * windScale;
vec4 nmap = texture(atlas, vec3(st, ATLAS_INDEX_WAVES_VERT10_NM)) * 2.0 - 1.0;
vec4 nmap1 = texture(atlas, vec3(st, ATLAS_INDEX_PERLIN_NOISE_NM)) * 2.0 - 1.0;
rotationmatrix(radians(3.0 * sin(osg_SimulationTime * 0.0075)), RotationMatrix);
st = vec2(waterTex2 * RotationMatrix * tscale) * windScale;
nmap += texture(atlas, vec3(st, ATLAS_INDEX_WAVES_VERT10_NM)) * 2.0 - 1.0;
nmap *= windEffect_low;
nmap1 *= windEffect_low;
// mix water and noise, modulated by factor
vec4 vNorm = normalize(mix(nmap, nmap1, mixFactor) * waveRoughness);
vNorm.r += ddx + ddx1 + ddx2 + ddx3;
st = vec2(waterTex1 + disdis * sca2) * windScale;
vec3 N0 = vec3(texture(atlas, vec3(st, ATLAS_INDEX_WAVES_VERT10_NM))) * 2.0 - 1.0;
st = vec2(waterTex1 + disdis * sca) * windScale;
vec3 N1 = vec3(texture(atlas, vec3(st, ATLAS_INDEX_PERLIN_NOISE_NM))) * 2.0 - 1.0;
st = vec2(waterTex1 * tscale) * windScale;
N0 += vec3(texture(atlas, vec3(st, ATLAS_INDEX_WAVES_VERT10_NM))) * 2.0 - 1.0;
N1 += vec3(texture(atlas, vec3(st, ATLAS_INDEX_PERLIN_NOISE_NM))) * 2.0 - 1.0;
rotationmatrix(radians(2.0 * sin(osg_SimulationTime * 0.005)), RotationMatrix);
st = vec2(waterTex2 * RotationMatrix * (tscale + sca2)) * windScale;
N0 += vec3(texture(atlas, vec3(st, ATLAS_INDEX_WAVES_VERT10_NM))) * 2.0 - 1.0;
N1 += vec3(texture(atlas, vec3(st, ATLAS_INDEX_PERLIN_NOISE_NM))) * 2.0 - 1.0;
rotationmatrix(radians(-4.0 * sin(osg_SimulationTime * 0.003)), RotationMatrix);
st = vec2(waterTex1 * RotationMatrix + disdis * sca2) * windScale;
N0 += vec3(texture(atlas, vec3(st, ATLAS_INDEX_WAVES_VERT10_NM))) * 2.0 - 1.0;
st = vec2(waterTex1 * RotationMatrix + disdis * sca) * windScale;
N1 += vec3(texture(atlas, vec3(st, ATLAS_INDEX_PERLIN_NOISE_NM))) * 2.0 - 1.0;
N0 *= windEffect_low;
N1 *= windEffect_low;
N0.r += (ddx + ddx1 + ddx2 + ddx3);
N0.g += (ddy + ddy1 + ddy2 + ddy3);
vec3 N = normalize(mix(Normal + N0, Normal + N1, mixFactor) * waveRoughness);
// From observation, the normal is generated in the wrong direction, resulting
// in specular highlights facing away from the Sun. This matrix attempts to correct it
mat3 rotMat = mat3(0.0, 0.0, 1.0,
0.0, 1.0, 0.0,
1.0, 0.0, 0.0);
N = N * rotMat;
return N;
}

View file

@ -22,10 +22,18 @@ uniform vec4 fg_textureLookup1[128];
uniform vec4 fg_textureLookup2[128];
uniform mat4 fg_zUpTransform;
uniform vec3 fg_modelOffset;
uniform sampler2D coastline;
const float TERRAIN_METALLIC = 0.0;
const float TERRAIN_ROUGHNESS = 0.95;
const vec3 WATER_COLOR = vec3(0.1, 0.1, 0.3);
const float WATER_METALLIC = 0.0;
const float WATER_ROUGHNESS = 0.25;
// Procedurally generate a water normal for this fragment
vec3 generateWaterNormal(in vec2 texCoords);
// gbuffer_pack.glsl
void gbuffer_pack(vec3 normal, vec3 base_color, float metallic, float roughness,
float occlusion, vec3 emissive, uint mat_id);
@ -38,6 +46,9 @@ void main()
{
vec3 texel;
vec4 specular = vec4(0.1, 0.1, 0.1, 1.0);
vec3 N = normalize(fs_in.vertex_normal);
float metallic = TERRAIN_METALLIC;
float roughness = TERRAIN_ROUGHNESS;
if (fg_photoScenery) {
texel = texture(landclass, vec2(fs_in.texcoord.s, 1.0 - fs_in.texcoord.t)).rgb;
@ -46,12 +57,13 @@ void main()
// The Landclass for this particular fragment. This can be used to
// index into the atlas textures.
int lc = int(texture2D(landclass, fs_in.texcoord).g * 255.0 + 0.5);
bool water = (texture2D(landclass, fs_in.texcoord).z > 0.9) || (texture2D(coastline, fs_in.texcoord).b > 0.05);
uint tex1 = uint(fg_textureLookup1[lc].r * 255.0 + 0.5);
//color = ambientArray[lc] + diffuseArray[lc] * NdotL * gl_LightSource[0].diffuse;
specular = fg_specularArray[lc];
// Different textures have different have different dimensions.
// Different textures have different dimensions.
vec2 atlas_dimensions = fg_dimensionsArray[lc].st;
vec2 atlas_scale = vec2(fg_tileWidth / atlas_dimensions.s, fg_tileHeight / atlas_dimensions.t );
vec2 st = atlas_scale * fs_in.texcoord;
@ -66,12 +78,16 @@ void main()
}
texel = texture(atlas, vec3(st, tex1)).rgb;
if (water) {
N = generateWaterNormal(fs_in.texcoord);
texel = WATER_COLOR;
roughness = WATER_ROUGHNESS;
metallic = WATER_METALLIC;
}
}
vec3 color = eotf_inverse_sRGB(texel);
vec3 N = normalize(fs_in.vertex_normal);
gbuffer_pack(N, color, TERRAIN_METALLIC, TERRAIN_ROUGHNESS, 1.0, vec3(0.0), 3u);
gbuffer_pack(N, color, metallic, roughness, 1.0, vec3(0.0), 3u);
gl_FragDepth = logdepth_encode(fs_in.flogz);
}