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@amelkor
Forked from JohnLambe/RealisticWater.gdshader
Created January 9, 2024 15:30
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/*
Realistic Water Shader for Godot 3.4
Modified to work with Godot 3.4 with thanks to jmarceno.
Copyright (c) 2019 UnionBytes, Achim Menzel (alias AiYori)
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-- UnionBytes
-- YouTube: www.youtube.com/user/UnionBytes
*/
// Modified to work with Godot 4.1.1, by John Lambe. My changes can be used without restriction or attribution (under the original licence of this, or CC0). //G4
// Not everything is properly converted. The foam effect is removed and the translucency is less realistic. //G4
// Lines modified to make this work in Godot 4.1.1 are commented with "//G4" (for the minimal changes to make it compile) //G4
// or "//G4B" for changes to resolve other problems observed. //G4
// For this shader min. GODOT 3.1.1 is required, because 3.1 has a depth buffer bug!
shader_type spatial;
render_mode cull_back,diffuse_burley,specular_schlick_ggx, blend_mix;
// To render backfaces (so that the water surface is visible when looking up at it from under the water), replace the line above with:
// render_mode cull_disabled,diffuse_burley,specular_schlick_ggx, blend_mix;
// Though that doesn't quite look correct (too opaque).
// Wave settings:
uniform float wave_speed = 0.5; // Speed scale for the waves
uniform vec4 wave_a = vec4(1.0, 1.0, 0.35, 3.0); // xy = Direction, z = Steepness, w = Length
uniform vec4 wave_b = vec4(1.0, 0.6, 0.30, 1.55); // xy = Direction, z = Steepness, w = Length
uniform vec4 wave_c = vec4(1.0, 1.3, 0.25, 0.9); // xy = Direction, z = Steepness, w = Length
// Surface settings:
uniform vec2 sampler_scale = vec2(0.25, 0.25); // Scale for the sampler
uniform vec2 sampler_direction= vec2(0.05, 0.04); // Direction and speed for the sampler offset
uniform sampler2D uv_sampler; //G4 : hint_aniso; // UV motion sampler for shifting the normalmap
uniform vec2 uv_sampler_scale = vec2(0.25, 0.25); // UV sampler scale
uniform float uv_sampler_strength = 0.04; // UV shifting strength
uniform sampler2D normalmap_a_sampler : hint_normal; // Normalmap sampler A
uniform sampler2D normalmap_b_sampler : hint_normal; // Normalmap sampler B
uniform sampler2D foam_sampler; //G4 : hint_black; // Foam sampler
uniform float foam_level = 0.5; // Foam level -> distance from the object (0.0 - 0.5)
// Volume settings:
uniform float refraction = 0.075; // Refraction of the water
uniform vec4 color_deep; //G4 : hint_color; // Color for deep places in the water, medium to dark blue
uniform vec4 color_shallow; //G4 : hint_color; // Color for lower places in the water, bright blue - green
uniform float beers_law = 2.0; // Beers law value, regulates the blending size to the deep water level
uniform float depth_offset = -0.75; // Offset for the blending
// Projector for the water caustics:
uniform mat4 projector; // Projector matrix, mostly the matric of the sun / directlight
uniform sampler2DArray caustic_sampler; //G4 : hint_black; // Caustic sampler, (Texture array with 16 Textures for the animation)
// Vertex -> Fragment:
varying float vertex_height; // Height of the water surface
varying vec3 vertex_normal; // Vertex normal -> Needed for refraction calculation
varying vec3 vertex_binormal; // Vertex binormal -> Needed for refraction calculation
varying vec3 vertex_tangent; // Vertex tangent -> Needed for refraction calculation
varying mat4 inv_mvp; // Inverse ModelViewProjection matrix -> Needed for caustic projection
uniform sampler2D DEPTH_TEXTURE : hint_depth_texture, filter_linear_mipmap; //G4
uniform sampler2D SCREEN_TEXTURE : hint_screen_texture, filter_linear_mipmap; //G4
// Wave function:
vec4 wave(vec4 parameter, vec2 position, float time, inout vec3 tangent, inout vec3 binormal)
{
float wave_steepness = parameter.z;
float wave_length = parameter.w;
float k = 2.0 * 3.14159265359 / wave_length;
float c = sqrt(9.8 / k);
vec2 d = normalize(parameter.xy);
float f = k * (dot(d, position) - c * time);
float a = wave_steepness / k;
tangent += normalize(vec3(1.0-d.x * d.x * (wave_steepness * sin(f)), d.x * (wave_steepness * cos(f)), -d.x * d.y * (wave_steepness * sin(f))));
binormal += normalize(vec3(-d.x * d.y * (wave_steepness * sin(f)), d.y * (wave_steepness * cos(f)), 1.0-d.y * d.y * (wave_steepness * sin(f))));
return vec4(d.x * (a * cos(f)), a * sin(f) * 0.25, d.y * (a * cos(f)), 0.0);
}
// Vertex shader:
void vertex()
{
float time = TIME * wave_speed;
vec4 vertex = vec4(VERTEX, 1.0);
vec3 vertex_position = (MODEL_MATRIX * vertex).xyz; //G4
vec3 tang = vec3(0.0, 0.0, 0.0);
vec3 bin = vec3(0.0, 0.0, 0.0);
vertex += wave(wave_a, vertex_position.xz, time, tang, bin);
vertex += wave(wave_b, vertex_position.xz, time, tang, bin);
vertex += wave(wave_c, vertex_position.xz, time, tang, bin);
vertex_tangent = tang;
vertex_binormal = bin;
vertex_position = vertex.xyz;
vertex_height = (PROJECTION_MATRIX * MODELVIEW_MATRIX * vertex).z;
TANGENT = vertex_tangent;
BINORMAL = vertex_binormal;
vertex_normal = normalize(cross(vertex_binormal, vertex_tangent));
NORMAL = vertex_normal;
UV = vertex.xz * sampler_scale;
VERTEX = vertex.xyz;
inv_mvp = inverse(PROJECTION_MATRIX * MODELVIEW_MATRIX);
}
// Fragment shader:
void fragment()
{
// Calculation of the UV with the UV motion sampler
vec2 uv_offset = sampler_direction * TIME;
vec2 uv_sampler_uv = UV * uv_sampler_scale + uv_offset;
vec2 uv_sampler_uv_offset = uv_sampler_strength * texture(uv_sampler, uv_sampler_uv).rg * 2.0 - 1.0;
vec2 uv = UV + uv_sampler_uv_offset;
// Normalmap:
vec3 normalmap = texture(normalmap_a_sampler, uv - uv_offset*2.0).rgb * 0.75; // 75 % sampler A
normalmap += texture(normalmap_b_sampler, uv + uv_offset).rgb * 0.25; // 25 % sampler B
// Refraction UV:
vec3 ref_normalmap = normalmap * 2.0 - 1.0;
ref_normalmap = normalize(vertex_tangent*ref_normalmap.x + vertex_binormal*ref_normalmap.y + vertex_normal*ref_normalmap.z);
vec2 ref_uv = SCREEN_UV + (ref_normalmap.xy * refraction) / vertex_height;
// Ground depth:
float depth_raw = texture(DEPTH_TEXTURE, ref_uv).r * 2.0 - 1.0;
float depth = PROJECTION_MATRIX[3][2] / (depth_raw + PROJECTION_MATRIX[2][2]);
float depth_blend = exp((depth+VERTEX.z + depth_offset) * -beers_law);
depth_blend = clamp(1.0-depth_blend, 0.0, 1.0);
float depth_blend_pow = clamp(pow(depth_blend, 2.5), 0.0, 1.0);
// Ground color:
vec3 screen_color = textureLod(SCREEN_TEXTURE, ref_uv, depth_blend_pow * 2.5).rgb;
vec3 dye_color = mix(color_shallow.rgb, color_deep.rgb, depth_blend_pow);
vec3 color = mix(screen_color*dye_color, dye_color*0.25, depth_blend_pow*0.5);
// Caustic screen projection
vec4 caustic_screenPos = vec4(ref_uv*2.0-1.0, depth_raw, 1.0);
vec4 caustic_localPos = inv_mvp * caustic_screenPos;
caustic_localPos = vec4(caustic_localPos.xyz/caustic_localPos.w, caustic_localPos.w);
vec2 caustic_Uv = caustic_localPos.xz / vec2(1024.0) + 0.5;
vec4 caustic_color = texture(caustic_sampler, vec3(caustic_Uv*300.0, mod(TIME*14.0, 16.0)));
color *= 1.0 + pow(caustic_color.r, 1.50) * (1.0-depth_blend) * 6.0;
/* //G4B: // Commented out because the foam effect was wrong in Godot 4.1.1 at certain viewing angles (appearing opaque).
// Foam:
if(depth + VERTEX.z < vertex_height-0.1)
{
float foam_noise = clamp(pow(texture(foam_sampler, (uv*4.0) - uv_offset).r, 10.0)*40.0, 0.0, 0.2);
float foam_mix = clamp(pow((1.0-(depth + VERTEX.z) + foam_noise), 8.0) * foam_noise * 0.4, 0.0, 1.0);
color = mix(color, vec3(1.0), foam_mix);
}
*/ // Commenting out the code above made the surface opaque. We add a less realistic translucency effect here: //G4B
color = mix(color,screen_color, 1.0 - depth_raw * 0.5); //G4B
// Set all values:
ALBEDO = color;
METALLIC = 0.1;
ROUGHNESS = 0.2;
SPECULAR = 0.2 + depth_blend_pow * 0.4;
NORMAL_MAP = normalmap; //G4
NORMAL_MAP_DEPTH = 1.25; //G4
}
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