You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
313 lines
6.6 KiB
313 lines
6.6 KiB
import {
|
|
Color,
|
|
Vector3
|
|
} from '../../../build/three.module.js';
|
|
|
|
/**
|
|
* God-rays (crepuscular rays)
|
|
*
|
|
* Similar implementation to the one used by Crytek for CryEngine 2 [Sousa2008].
|
|
* Blurs a mask generated from the depth map along radial lines emanating from the light
|
|
* source. The blur repeatedly applies a blur filter of increasing support but constant
|
|
* sample count to produce a blur filter with large support.
|
|
*
|
|
* My implementation performs 3 passes, similar to the implementation from Sousa. I found
|
|
* just 6 samples per pass produced acceptible results. The blur is applied three times,
|
|
* with decreasing filter support. The result is equivalent to a single pass with
|
|
* 6*6*6 = 216 samples.
|
|
*
|
|
* References:
|
|
*
|
|
* Sousa2008 - Crysis Next Gen Effects, GDC2008, http://www.crytek.com/sites/default/files/GDC08_SousaT_CrysisEffects.ppt
|
|
*/
|
|
|
|
const GodRaysDepthMaskShader = {
|
|
|
|
uniforms: {
|
|
|
|
tInput: {
|
|
value: null
|
|
}
|
|
|
|
},
|
|
|
|
vertexShader: /* glsl */`
|
|
|
|
varying vec2 vUv;
|
|
|
|
void main() {
|
|
|
|
vUv = uv;
|
|
gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
|
|
|
|
}`,
|
|
|
|
fragmentShader: /* glsl */`
|
|
|
|
varying vec2 vUv;
|
|
|
|
uniform sampler2D tInput;
|
|
|
|
void main() {
|
|
|
|
gl_FragColor = vec4( 1.0 ) - texture2D( tInput, vUv );
|
|
|
|
}`
|
|
|
|
};
|
|
|
|
|
|
/**
|
|
* The god-ray generation shader.
|
|
*
|
|
* First pass:
|
|
*
|
|
* The depth map is blurred along radial lines towards the "sun". The
|
|
* output is written to a temporary render target (I used a 1/4 sized
|
|
* target).
|
|
*
|
|
* Pass two & three:
|
|
*
|
|
* The results of the previous pass are re-blurred, each time with a
|
|
* decreased distance between samples.
|
|
*/
|
|
|
|
const GodRaysGenerateShader = {
|
|
|
|
uniforms: {
|
|
|
|
tInput: {
|
|
value: null
|
|
},
|
|
fStepSize: {
|
|
value: 1.0
|
|
},
|
|
vSunPositionScreenSpace: {
|
|
value: new Vector3()
|
|
}
|
|
|
|
},
|
|
|
|
vertexShader: /* glsl */`
|
|
|
|
varying vec2 vUv;
|
|
|
|
void main() {
|
|
|
|
vUv = uv;
|
|
gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
|
|
|
|
}`,
|
|
|
|
fragmentShader: /* glsl */`
|
|
|
|
#define TAPS_PER_PASS 6.0
|
|
|
|
varying vec2 vUv;
|
|
|
|
uniform sampler2D tInput;
|
|
|
|
uniform vec3 vSunPositionScreenSpace;
|
|
uniform float fStepSize; // filter step size
|
|
|
|
void main() {
|
|
|
|
// delta from current pixel to "sun" position
|
|
|
|
vec2 delta = vSunPositionScreenSpace.xy - vUv;
|
|
float dist = length( delta );
|
|
|
|
// Step vector (uv space)
|
|
|
|
vec2 stepv = fStepSize * delta / dist;
|
|
|
|
// Number of iterations between pixel and sun
|
|
|
|
float iters = dist/fStepSize;
|
|
|
|
vec2 uv = vUv.xy;
|
|
float col = 0.0;
|
|
|
|
// This breaks ANGLE in Chrome 22
|
|
// - see http://code.google.com/p/chromium/issues/detail?id=153105
|
|
|
|
/*
|
|
// Unrolling didnt do much on my hardware (ATI Mobility Radeon 3450),
|
|
// so i've just left the loop
|
|
|
|
"for ( float i = 0.0; i < TAPS_PER_PASS; i += 1.0 ) {",
|
|
|
|
// Accumulate samples, making sure we dont walk past the light source.
|
|
|
|
// The check for uv.y < 1 would not be necessary with "border" UV wrap
|
|
// mode, with a black border color. I don't think this is currently
|
|
// exposed by three.js. As a result there might be artifacts when the
|
|
// sun is to the left, right or bottom of screen as these cases are
|
|
// not specifically handled.
|
|
|
|
" col += ( i <= iters && uv.y < 1.0 ? texture2D( tInput, uv ).r : 0.0 );",
|
|
" uv += stepv;",
|
|
|
|
"}",
|
|
*/
|
|
|
|
// Unrolling loop manually makes it work in ANGLE
|
|
|
|
float f = min( 1.0, max( vSunPositionScreenSpace.z / 1000.0, 0.0 ) ); // used to fade out godrays
|
|
|
|
if ( 0.0 <= iters && uv.y < 1.0 ) col += texture2D( tInput, uv ).r * f;
|
|
uv += stepv;
|
|
|
|
if ( 1.0 <= iters && uv.y < 1.0 ) col += texture2D( tInput, uv ).r * f;
|
|
uv += stepv;
|
|
|
|
if ( 2.0 <= iters && uv.y < 1.0 ) col += texture2D( tInput, uv ).r * f;
|
|
uv += stepv;
|
|
|
|
if ( 3.0 <= iters && uv.y < 1.0 ) col += texture2D( tInput, uv ).r * f;
|
|
uv += stepv;
|
|
|
|
if ( 4.0 <= iters && uv.y < 1.0 ) col += texture2D( tInput, uv ).r * f;
|
|
uv += stepv;
|
|
|
|
if ( 5.0 <= iters && uv.y < 1.0 ) col += texture2D( tInput, uv ).r * f;
|
|
uv += stepv;
|
|
|
|
// Should technically be dividing by 'iters but 'TAPS_PER_PASS' smooths out
|
|
// objectionable artifacts, in particular near the sun position. The side
|
|
// effect is that the result is darker than it should be around the sun, as
|
|
// TAPS_PER_PASS is greater than the number of samples actually accumulated.
|
|
// When the result is inverted (in the shader 'godrays_combine this produces
|
|
// a slight bright spot at the position of the sun, even when it is occluded.
|
|
|
|
gl_FragColor = vec4( col/TAPS_PER_PASS );
|
|
gl_FragColor.a = 1.0;
|
|
|
|
}`
|
|
|
|
};
|
|
|
|
/**
|
|
* Additively applies god rays from texture tGodRays to a background (tColors).
|
|
* fGodRayIntensity attenuates the god rays.
|
|
*/
|
|
|
|
const GodRaysCombineShader = {
|
|
|
|
uniforms: {
|
|
|
|
tColors: {
|
|
value: null
|
|
},
|
|
|
|
tGodRays: {
|
|
value: null
|
|
},
|
|
|
|
fGodRayIntensity: {
|
|
value: 0.69
|
|
}
|
|
|
|
},
|
|
|
|
vertexShader: /* glsl */`
|
|
|
|
varying vec2 vUv;
|
|
|
|
void main() {
|
|
|
|
vUv = uv;
|
|
gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
|
|
|
|
}`,
|
|
|
|
fragmentShader: /* glsl */`
|
|
|
|
varying vec2 vUv;
|
|
|
|
uniform sampler2D tColors;
|
|
uniform sampler2D tGodRays;
|
|
|
|
uniform float fGodRayIntensity;
|
|
|
|
void main() {
|
|
|
|
// Since THREE.MeshDepthMaterial renders foreground objects white and background
|
|
// objects black, the god-rays will be white streaks. Therefore value is inverted
|
|
// before being combined with tColors
|
|
|
|
gl_FragColor = texture2D( tColors, vUv ) + fGodRayIntensity * vec4( 1.0 - texture2D( tGodRays, vUv ).r );
|
|
gl_FragColor.a = 1.0;
|
|
|
|
}`
|
|
|
|
};
|
|
|
|
|
|
/**
|
|
* A dodgy sun/sky shader. Makes a bright spot at the sun location. Would be
|
|
* cheaper/faster/simpler to implement this as a simple sun sprite.
|
|
*/
|
|
|
|
const GodRaysFakeSunShader = {
|
|
|
|
uniforms: {
|
|
|
|
vSunPositionScreenSpace: {
|
|
value: new Vector3()
|
|
},
|
|
|
|
fAspect: {
|
|
value: 1.0
|
|
},
|
|
|
|
sunColor: {
|
|
value: new Color( 0xffee00 )
|
|
},
|
|
|
|
bgColor: {
|
|
value: new Color( 0x000000 )
|
|
}
|
|
|
|
},
|
|
|
|
vertexShader: /* glsl */`
|
|
|
|
varying vec2 vUv;
|
|
|
|
void main() {
|
|
|
|
vUv = uv;
|
|
gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
|
|
|
|
}`,
|
|
|
|
fragmentShader: /* glsl */`
|
|
|
|
varying vec2 vUv;
|
|
|
|
uniform vec3 vSunPositionScreenSpace;
|
|
uniform float fAspect;
|
|
|
|
uniform vec3 sunColor;
|
|
uniform vec3 bgColor;
|
|
|
|
void main() {
|
|
|
|
vec2 diff = vUv - vSunPositionScreenSpace.xy;
|
|
|
|
// Correct for aspect ratio
|
|
|
|
diff.x *= fAspect;
|
|
|
|
float prop = clamp( length( diff ) / 0.5, 0.0, 1.0 );
|
|
prop = 0.35 * pow( 1.0 - prop, 3.0 );
|
|
|
|
gl_FragColor.xyz = ( vSunPositionScreenSpace.z > 0.0 ) ? mix( sunColor, bgColor, 1.0 - prop ) : bgColor;
|
|
gl_FragColor.w = 1.0;
|
|
|
|
}`
|
|
|
|
};
|
|
|
|
export { GodRaysDepthMaskShader, GodRaysGenerateShader, GodRaysCombineShader, GodRaysFakeSunShader };
|
|
|