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# WebGL Water
# https://madebyevan.com/webgl-water/
# Copyright 2011 Evan Wallace
# Released under the MIT license
import os
import glm
from light_gl import *
from water import Water
import moderngl
def local(*path):
return os.path.join(os.path.dirname(__file__), *path)
def local_textures(path):
return local("../data/textures", path)
class Renderer():
_helper_functions = """
const float IOR_AIR = 1.0;
const float IOR_WATER = 1.333;
const vec3 abovewaterColor = vec3(0.25, 1.0, 1.25);
const vec3 underwaterColor = vec3(0.4, 0.9, 1.0);
const float poolHeight = 1.0;
uniform vec3 light;
uniform vec3 sphereCenter;
uniform float sphereRadius;
uniform sampler2D tiles;
uniform sampler2D causticTex;
uniform sampler2D water;
vec2 intersectCube(vec3 origin, vec3 ray, vec3 cubeMin, vec3 cubeMax) {
vec3 tMin = (cubeMin - origin) / ray;
vec3 tMax = (cubeMax - origin) / ray;
vec3 t1 = min(tMin, tMax);
vec3 t2 = max(tMin, tMax);
float tNear = max(max(t1.x, t1.y), t1.z);
float tFar = min(min(t2.x, t2.y), t2.z);
return vec2(tNear, tFar);
}
float intersectSphere(vec3 origin, vec3 ray, vec3 sphereCenter, float sphereRadius) {
vec3 toSphere = origin - sphereCenter;
float a = dot(ray, ray);
float b = 2.0 * dot(toSphere, ray);
float c = dot(toSphere, toSphere) - sphereRadius * sphereRadius;
float discriminant = b*b - 4.0*a*c;
if (discriminant > 0.0) {
float t = (-b - sqrt(discriminant)) / (2.0 * a);
if (t > 0.0) return t;
}
return 1.0e6;
}
vec3 getSphereColor(vec3 point) {
vec3 color = vec3(0.5);
/* ambient occlusion with walls */
color *= 1.0 - 0.9 / pow((1.0 + sphereRadius - abs(point.x)) / sphereRadius, 3.0);
color *= 1.0 - 0.9 / pow((1.0 + sphereRadius - abs(point.z)) / sphereRadius, 3.0);
color *= 1.0 - 0.9 / pow((point.y + 1.0 + sphereRadius) / sphereRadius, 3.0);
/* caustics */
vec3 sphereNormal = (point - sphereCenter) / sphereRadius;
vec3 refractedLight = refract(-light, vec3(0.0, 1.0, 0.0), IOR_AIR / IOR_WATER);
float diffuse = max(0.0, dot(-refractedLight, sphereNormal)) * 0.5;
vec4 info = texture2D(water, point.xz * 0.5 + 0.5);
if (point.y < info.r) {
vec4 caustic = texture2D(causticTex, 0.75 * (point.xz - point.y * refractedLight.xz / refractedLight.y) * 0.5 + 0.5);
diffuse *= caustic.r * 4.0;
}
color += diffuse;
return color;
}
vec3 getWallColor(vec3 point) {
float scale = 0.5;
vec3 wallColor;
vec3 normal;
if (abs(point.x) > 0.999) {
wallColor = texture2D(tiles, point.yz * 0.5 + vec2(1.0, 0.5)).rgb;
normal = vec3(-point.x, 0.0, 0.0);
} else if (abs(point.z) > 0.999) {
wallColor = texture2D(tiles, point.yx * 0.5 + vec2(1.0, 0.5)).rgb;
normal = vec3(0.0, 0.0, -point.z);
} else {
wallColor = texture2D(tiles, point.xz * 0.5 + 0.5).rgb;
normal = vec3(0.0, 1.0, 0.0);
}
scale /= length(point); /* pool ambient occlusion */
scale *= 1.0 - 0.9 / pow(length(point - sphereCenter) / sphereRadius, 4.0); /* sphere ambient occlusion */
/* caustics */
vec3 refractedLight = -refract(-light, vec3(0.0, 1.0, 0.0), IOR_AIR / IOR_WATER);
float diffuse = max(0.0, dot(refractedLight, normal));
vec4 info = texture2D(water, point.xz * 0.5 + 0.5);
if (point.y < info.r) {
vec4 caustic = texture2D(causticTex, 0.75 * (point.xz - point.y * refractedLight.xz / refractedLight.y) * 0.5 + 0.5);
scale += diffuse * caustic.r * 2.0 * caustic.g;
} else {
/* shadow for the rim of the pool */
vec2 t = intersectCube(point, refractedLight, vec3(-1.0, -poolHeight, -1.0), vec3(1.0, 2.0, 1.0));
diffuse *= 1.0 / (1.0 + exp(-200.0 / (1.0 + 10.0 * (t.y - t.x)) * (point.y + refractedLight.y * t.y - 2.0 / 12.0)));
scale += diffuse * 0.5;
}
return wallColor * scale;
}
"""
def _splice(array: list, start: int, num: int):
new_array = []
exclude_range = range(start, start + num)
for idx, elem in enumerate(array):
if idx not in exclude_range:
new_array.append(elem)
return new_array
def _water_shader(ctx: moderngl.Context, under_water: bool):
vert_shader = """
uniform sampler2D water;
varying vec3 position;
void main() {
vec4 info = texture2D(water, gl_Vertex.xy * 0.5 + 0.5);
position = gl_Vertex.xzy;
position.y += info.r;
gl_Position = gl_ModelViewProjectionMatrix * vec4(position, 1.0);
}
"""
if under_water:
water_frag_shader = """
/* underwater */
normal = -normal;
vec3 reflectedRay = reflect(incomingRay, normal);
vec3 refractedRay = refract(incomingRay, normal, IOR_WATER / IOR_AIR);
float fresnel = mix(0.5, 1.0, pow(1.0 - dot(normal, -incomingRay), 3.0));
vec3 reflectedColor = getSurfaceRayColor(position, reflectedRay, underwaterColor);
vec3 refractedColor = getSurfaceRayColor(position, refractedRay, vec3(1.0)) * vec3(0.8, 1.0, 1.1);
gl_FragColor = vec4(mix(reflectedColor, refractedColor, (1.0 - fresnel) * length(refractedRay)), 1.0);
"""
else:
water_frag_shader = """
/* above water */
vec3 reflectedRay = reflect(incomingRay, normal);
vec3 refractedRay = refract(incomingRay, normal, IOR_AIR / IOR_WATER);
float fresnel = mix(0.25, 1.0, pow(1.0 - dot(normal, -incomingRay), 3.0));
vec3 reflectedColor = getSurfaceRayColor(position, reflectedRay, abovewaterColor);
vec3 refractedColor = getSurfaceRayColor(position, refractedRay, abovewaterColor);
gl_FragColor = vec4(mix(refractedColor, reflectedColor, fresnel), 1.0);
"""
frag_shader = """
uniform vec3 eye;
varying vec3 position;
uniform samplerCube sky;
vec3 getSurfaceRayColor(vec3 origin, vec3 ray, vec3 waterColor) {
vec3 color;
float q = intersectSphere(origin, ray, sphereCenter, sphereRadius);
if (q < 1.0e6) {
color = getSphereColor(origin + ray * q);
} else if (ray.y < 0.0) {
vec2 t = intersectCube(origin, ray, vec3(-1.0, -poolHeight, -1.0), vec3(1.0, 2.0, 1.0));
color = getWallColor(origin + ray * t.y);
} else {
vec2 t = intersectCube(origin, ray, vec3(-1.0, -poolHeight, -1.0), vec3(1.0, 2.0, 1.0));
vec3 hit = origin + ray * t.y;
if (hit.y < 2.0 / 12.0) {
color = getWallColor(hit);
} else {
color = textureCube(sky, ray).rgb;
color += vec3(pow(max(0.0, dot(light, ray)), 5000.0)) * vec3(10.0, 8.0, 6.0);
}
}
if (ray.y < 0.0) color *= waterColor;
return color;
}
void main() {
vec2 coord = position.xz * 0.5 + 0.5;
vec4 info = texture2D(water, coord);
/* make water look more "peaked" */
for (int i = 0; i < 5; i++) {
coord += info.ba * 0.005;
info = texture2D(water, coord);
}
vec3 normal = vec3(info.b, sqrt(1.0 - dot(info.ba, info.ba)), info.a);
vec3 incomingRay = normalize(position - eye);
""" + water_frag_shader + """}"""
return Shader(vert_shader, Renderer._helper_functions + frag_shader, ctx)
def __init__(self, ctx: moderngl.Context) -> None:
self.ctx = ctx
self.tile_texture = ImageTexture(
local_textures("tiles.jpg"), "RGB", ctx, (True, True, True), mipmaps=True)
self.light_dir = glm.normalize(glm.vec3(2.0, 2.0, -1.0))
# water
self.water_mesh = MeshBuilder.panel(detail=200).build(ctx)
self.water_shaders: list[Shader] = []
for under_water in (False, True):
self.water_shaders.append(Renderer._water_shader(ctx, under_water))
# sphere
self.sphere_mesh = MeshBuilder.sphere(detail=10).build(ctx)
self.sphere_shader = Shader(Renderer._helper_functions + """
varying vec3 position;
void main() {
position = sphereCenter + gl_Vertex.xyz * sphereRadius;
gl_Position = gl_ModelViewProjectionMatrix * vec4(position, 1.0);
}
""", Renderer._helper_functions + """
varying vec3 position;
void main() {
gl_FragColor = vec4(getSphereColor(position), 1.0);
vec4 info = texture2D(water, position.xz * 0.5 + 0.5);
if (position.y < info.r) {
gl_FragColor.rgb *= underwaterColor * 1.2;
}
}""", ctx)
self.sphere_center = glm.vec3(0.0)
self.sphere_radius = 0
# cude
cude_mesh_builder = MeshBuilder.cube()
# remove cude top
cude_mesh_builder.triangles = np.array(Renderer._splice(
cude_mesh_builder.triangles, 4, 2), dtype=np.int32)
self.cube_mesh = cude_mesh_builder.build(ctx)
self.cude_shader = Shader(Renderer._helper_functions + """
varying vec3 position;
void main() {
position = gl_Vertex.xyz;
position.y = ((1.0 - position.y) * (7.0 / 12.0) - 1.0) * poolHeight;
gl_Position = gl_ModelViewProjectionMatrix * vec4(position, 1.0);
}""", Renderer._helper_functions + """
varying vec3 position;
void main() {
gl_FragColor = vec4(getWallColor(position), 1.0);
vec4 info = texture2D(water, position.xz * 0.5 + 0.5);
if (position.y < info.r) {
gl_FragColor.rgb *= underwaterColor * 1.2;
}
}""", ctx)
self.caustic_texture = RawTexture((1024, 1024), ctx=ctx)
self.caustics_shader = Shader(Renderer._helper_functions + """
varying vec3 oldPos;
varying vec3 newPos;
varying vec3 ray;
/* project the ray onto the plane */
vec3 project(vec3 origin, vec3 ray, vec3 refractedLight) {
vec2 tcube = intersectCube(origin, ray, vec3(-1.0, -poolHeight, -1.0), vec3(1.0, 2.0, 1.0));
origin += ray * tcube.y;
float tplane = (-origin.y - 1.0) / refractedLight.y;
return origin + refractedLight * tplane;
}
void main() {
vec4 info = texture2D(water, gl_Vertex.xy * 0.5 + 0.5);
info.ba *= 0.5;
vec3 normal = vec3(info.b, sqrt(1.0 - dot(info.ba, info.ba)), info.a);
/* project the vertices along the refracted vertex ray */
vec3 refractedLight = refract(-light, vec3(0.0, 1.0, 0.0), IOR_AIR / IOR_WATER);
ray = refract(-light, normal, IOR_AIR / IOR_WATER);
oldPos = project(gl_Vertex.xzy, refractedLight, refractedLight);
newPos = project(gl_Vertex.xzy + vec3(0.0, info.r, 0.0), ray, refractedLight);
gl_Position = vec4(0.75 * (newPos.xz + refractedLight.xz / refractedLight.y), 0.0, 1.0);
}""", Renderer._helper_functions + """
varying vec3 oldPos;
varying vec3 newPos;
varying vec3 ray;
void main() {
/* if the triangle gets smaller, it gets brighter, and vice versa */
float oldArea = length(dFdx(oldPos)) * length(dFdy(oldPos));
float newArea = length(dFdx(newPos)) * length(dFdy(newPos));
gl_FragColor = vec4(oldArea / newArea * 0.2, 1.0, 0.0, 0.0);
vec3 refractedLight = refract(-light, vec3(0.0, 1.0, 0.0), IOR_AIR / IOR_WATER);
/* compute a blob shadow and make sure we only draw a shadow if the player is blocking the light */
vec3 dir = (sphereCenter - newPos) / sphereRadius;
vec3 area = cross(dir, refractedLight);
float shadow = dot(area, area);
float dist = dot(dir, -refractedLight);
shadow = 1.0 + (shadow - 1.0) / (0.05 + dist * 0.025);
shadow = clamp(1.0 / (1.0 + exp(-shadow)), 0.0, 1.0);
shadow = mix(1.0, shadow, clamp(dist * 2.0, 0.0, 1.0));
gl_FragColor.g = shadow;
/* shadow for the rim of the pool */
vec2 t = intersectCube(newPos, -refractedLight, vec3(-1.0, -poolHeight, -1.0), vec3(1.0, 2.0, 1.0));
gl_FragColor.r *= 1.0 / (1.0 + exp(-200.0 / (1.0 + 10.0 * (t.y - t.x)) * (newPos.y - refractedLight.y * t.y - 2.0 / 12.0)));
}""", ctx)
self.sky = Cubemap(local_textures("xpos.jpg"), local_textures("xneg.jpg"), local_textures("ypos.jpg"),
local_textures("ypos.jpg"), local_textures("zpos.jpg"), local_textures("zneg.jpg"), ctx)
def update_caustics(self, matrices: Matrices, water: Water):
self.caustic_texture.draw_to(self.ctx)
self.ctx.clear()
water.texture_a.use(0)
self.caustics_shader.draw_mesh(self.water_mesh, matrices, unifroms={
"light": self.light_dir,
"water": 0,
"sphereCenter": self.sphere_center,
"sphereRadius": self.sphere_radius,
})
def render_water(self, matrices: Matrices, water: Water):
water.texture_a.use(0)
self.tile_texture.use(1)
self.sky.use(2)
self.caustic_texture.use(3)
self.ctx.enable(moderngl.CULL_FACE)
cull_face = ("front", "back")
for idx in range(2):
self.ctx.cull_face = cull_face[idx]
self.water_shaders[idx].draw_mesh(self.water_mesh, matrices, unifroms={
"light": self.light_dir,
"water": 0,
"tiles": 1,
"sky": 2,
"causticTex": 3,
"eye": matrices.eye,
"sphereCenter": self.sphere_center,
"sphereRadius": self.sphere_radius,
})
self.ctx.disable(moderngl.CULL_FACE)
def render_sphere(self, matrices: Matrices, water: Water):
water.texture_a.use(0)
self.caustic_texture.use(1)
self.sphere_shader.draw_mesh(self.sphere_mesh, matrices, unifroms={
"light": self.light_dir,
"water": 0,
"causticTex": 1,
"sphereCenter": self.sphere_center,
"sphereRadius": self.sphere_radius
})
def render_cude(self, matrices: Matrices, water: Water):
self.ctx.enable(moderngl.CULL_FACE)
water.texture_a.use(0)
self.tile_texture.use(1)
self.caustic_texture.use(2)
self.cude_shader.draw_mesh(self.cube_mesh, matrices, unifroms={
"light": self.light_dir,
"water": 0,
"tiles": 1,
"causticTex": 2,
"sphereCenter": self.sphere_center,
"sphereRadius": self.sphere_radius
})
self.ctx.disable(moderngl.CULL_FACE)
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