Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Continuation of x2048's Cascaded Shadows #13956

Closed
wants to merge 3 commits into from
Closed

Continuation of x2048's Cascaded Shadows #13956

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
1dbe225
Initial Cascaded Shadows
x2048 Nov 5, 2023
74717d0
Fix z perspective bias
lhofhansl Nov 5, 2023
e9d8349
Adjust cascade size to shadow range
lhofhansl Nov 5, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Jump to
Jump to file
Failed to load files.
Diff view
Diff view
12 changes: 7 additions & 5 deletions builtin/settingtypes.txt
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -498,14 +498,14 @@ shadow_strength_gamma (Shadow strength gamma) float 1.0 0.1 10.0
# Maximum distance to render shadows.
#
# Requires: shaders, enable_dynamic_shadows, opengl
shadow_map_max_distance (Shadow map max distance in nodes to render shadows) float 140.0 10.0 1000.0
shadow_map_max_distance (Shadow map max distance in nodes to render shadows) float 200.0 10.0 1000.0

# Texture size to render the shadow map on.
# This must be a power of two.
# Bigger numbers create better shadows but it is also more expensive.
#
# Requires: shaders, enable_dynamic_shadows, opengl
shadow_map_texture_size (Shadow map texture size) int 2048 128 8192
shadow_map_texture_size (Shadow map texture size) int 1024 128 8192

# Sets shadow texture quality to 32 bits.
# On false, 16 bits texture will be used.
Expand All @@ -524,8 +524,10 @@ shadow_poisson_filter (Poisson filtering) bool true
# This simulates the soft shadows effect by applying a PCF or Poisson disk
# but also uses more resources.
#
# Note: Setting 1 enables simple 2x2 bilinear filter
#
# Requires: shaders, enable_dynamic_shadows, opengl
shadow_filters (Shadow filter quality) enum 1 0,1,2
shadow_filters (Shadow filter quality) enum 1 0,1,2,3

# Enable colored shadows.
# On true translucent nodes cast colored shadows. This is expensive.
Expand All @@ -536,10 +538,10 @@ shadow_map_color (Colored shadows) bool false
# Spread a complete update of shadow map over given number of frames.
# Higher values might make shadows laggy, lower values
# will consume more resources.
# Minimum value: 1; maximum value: 16
# Minimum value: 1; maximum value: 64
#
# Requires: shaders, enable_dynamic_shadows, opengl
shadow_update_frames (Map shadows update frames) int 8 1 16
shadow_update_frames (Map shadows update frames) int 16 1 64

# Set the soft shadow radius size.
# Lower values mean sharper shadows, bigger values mean softer shadows.
Expand Down
166 changes: 138 additions & 28 deletions client/shaders/nodes_shader/opengl_fragment.glsl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -15,18 +15,25 @@ uniform float animationTimer;
// shadow uniforms
uniform vec3 v_LightDirection;
uniform float f_textureresolution;
uniform mat4 m_ShadowViewProj;
uniform float f_shadowfar;
uniform float f_shadow_strength;
uniform vec4 CameraPos;
uniform float xyPerspectiveBias0;
uniform float xyPerspectiveBias1;
uniform float zPerspectiveBias;

struct ShadowCascade {
mat4 mViewProj; // view-projection matrix
float boundary; // boundary of the cascade in scene space
vec3 center; // center of the frustum in scene space
};

#define MAX_SHADOW_CASCADES 3

uniform ShadowCascade shadowCascades[MAX_SHADOW_CASCADES];
uniform int cascadeCount;

varying vec3 shadow_world_position;
varying float adj_shadow_strength;
varying float cosLight;
varying float f_normal_length;
varying vec3 shadow_position;
varying float perspective_factor;
#endif


Expand All @@ -52,15 +59,31 @@ varying vec3 tsLightVec;

#ifdef ENABLE_DYNAMIC_SHADOWS

// assuming near is always 1.0
float getLinearDepth()
int getCascade()
{
return 2.0 * f_shadowfar / (f_shadowfar + 1.0 - (2.0 * gl_FragCoord.z - 1.0) * (f_shadowfar - 1.0));
for (int i = 0; i < MAX_SHADOW_CASCADES; i++) {
if (i == cascadeCount)
break;
vec3 center_to_fragment = shadow_world_position - shadowCascades[i].center;
float projected_distance = length(center_to_fragment - v_LightDirection * dot(center_to_fragment, v_LightDirection));

if (shadowCascades[i].boundary > projected_distance)
return i;
}
return cascadeCount - 1;
}

vec3 getLightSpacePosition()
int cascade = getCascade();

vec3 getLightSpacePosition(int cascade)
{
return shadow_position * 0.5 + 0.5;
float cosine = dot(vNormal, v_LightDirection); // cos(angle(light, normal))
float offset = pow(1. - pow(cosine, 2.), 0.5); // sin(angle...)
offset *= 2. * shadowCascades[cascade].boundary / f_textureresolution * (cosine > 0. ? -1. : 1.);
vec4 shadow_position = shadowCascades[cascade].mViewProj * vec4(shadow_world_position + vNormal * offset, 1.0);
shadow_position /= shadow_position.w;
shadow_position.z = shadow_position.z * zPerspectiveBias - 1e-3 * shadowCascades[cascade].boundary / f_textureresolution;
return shadow_position.xyz * 0.5 + 0.5;
}
// custom smoothstep implementation because it's not defined in glsl1.2
// https://docs.gl/sl4/smoothstep
Expand Down Expand Up @@ -97,14 +120,42 @@ vec4 getHardShadowColor(sampler2D shadowsampler, vec2 smTexCoord, float realDist
vec4 texDepth = texture2D(shadowsampler, smTexCoord.xy).rgba;

float visibility = step(0.0, realDistance - texDepth.r);
vec4 result = vec4(visibility, vec3(0.0,0.0,0.0));//unpackColor(texDepth.g));
vec4 result = vec4(visibility, vec3(0.0,0.0,0.0));
if (visibility < 0.1) {
visibility = step(0.0, realDistance - texDepth.b);
result = vec4(visibility, unpackColor(texDepth.a));
visibility = step(0.0, realDistance - texDepth.g);
result = vec4(visibility, unpackColor(texDepth.b));
}
return result;
}

#if SHADOW_FILTER == 1
vec4 getFilteredShadowColor(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
{
vec2 texelSize = vec2(1. / f_textureresolution / cascadeCount, 1. / f_textureresolution);
vec2 texelCoord = smTexCoord * vec2(f_textureresolution * cascadeCount, f_textureresolution);

vec2 fraction = texelCoord - floor(texelCoord);
float scale = 1.0;
vec2 sampleTexCoord = (floor(texelCoord) + 0.5 * scale) * texelSize;

float texDepth = texture2D(shadowsampler, sampleTexCoord).r;
vec4 visibility = (1. - fraction.x) * (1. - fraction.y) * getHardShadowColor(shadowsampler, sampleTexCoord, realDistance);

sampleTexCoord.x += texelSize.x * scale;
texDepth = texture2D(shadowsampler, sampleTexCoord).r;
visibility += fraction.x * (1. - fraction.y) * getHardShadowColor(shadowsampler, sampleTexCoord, realDistance);

sampleTexCoord.y += texelSize.y * scale;
texDepth = texture2D(shadowsampler, sampleTexCoord).r;
visibility += fraction.x * fraction.y * getHardShadowColor(shadowsampler, sampleTexCoord, realDistance);

sampleTexCoord.x -= texelSize.x * scale;
texDepth = texture2D(shadowsampler, sampleTexCoord).r;
visibility += (1. - fraction.x) * fraction.y * getHardShadowColor(shadowsampler, sampleTexCoord, realDistance);
return visibility;
}
#endif

#else

float getHardShadow(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
Expand All @@ -114,13 +165,41 @@ float getHardShadow(sampler2D shadowsampler, vec2 smTexCoord, float realDistance
return visibility;
}

#if SHADOW_FILTER == 1
float getFilteredShadow(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
{
vec2 texelSize = vec2(1. / f_textureresolution / cascadeCount, 1. / f_textureresolution);
vec2 texelCoord = smTexCoord * vec2(f_textureresolution * cascadeCount, f_textureresolution);

vec2 fraction = texelCoord - floor(texelCoord);
float scale = 1.0;
vec2 sampleTexCoord = (floor(texelCoord) + 0.5 * scale) * texelSize;

float texDepth = texture2D(shadowsampler, sampleTexCoord).r;
float visibility = (1. - fraction.x) * (1. - fraction.y) * getHardShadow(shadowsampler, sampleTexCoord, realDistance);

sampleTexCoord.x += texelSize.x * scale;
texDepth = texture2D(shadowsampler, sampleTexCoord).r;
visibility += fraction.x * (1. - fraction.y) * getHardShadow(shadowsampler, sampleTexCoord, realDistance);

sampleTexCoord.y += texelSize.y * scale;
texDepth = texture2D(shadowsampler, sampleTexCoord).r;
visibility += fraction.x * fraction.y * getHardShadow(shadowsampler, sampleTexCoord, realDistance);

sampleTexCoord.x -= texelSize.x * scale;
texDepth = texture2D(shadowsampler, sampleTexCoord).r;
visibility += (1. - fraction.x) * fraction.y * getHardShadow(shadowsampler, sampleTexCoord, realDistance);
return visibility;
}
#endif

#endif


#if SHADOW_FILTER == 2
#if SHADOW_FILTER == 3
#define PCFBOUND 2.0 // 5x5
#define PCFSAMPLES 25
#elif SHADOW_FILTER == 1
#elif SHADOW_FILTER == 2
#define PCFBOUND 1.0 // 3x3
#define PCFSAMPLES 9
#else
Expand Down Expand Up @@ -156,19 +235,18 @@ float getPenumbraRadius(sampler2D shadowsampler, vec2 smTexCoord, float realDist
float y, x;
float depth = getHardShadowDepth(shadowsampler, smTexCoord.xy, realDistance);
// A factor from 0 to 1 to reduce blurring of short shadows
float sharpness_factor = 1.0;
float sharpness_factor = 0.0;
// conversion factor from shadow depth to blur radius
float depth_to_blur = f_shadowfar / SOFTSHADOWRADIUS / xyPerspectiveBias0;
float depth_to_blur = f_shadowfar / SOFTSHADOWRADIUS;
if (depth > 0.0 && f_normal_length > 0.0)
// 5 is empirical factor that controls how fast shadow loses sharpness
sharpness_factor = clamp(5.0 * depth * depth_to_blur, 0.0, 1.0);
sharpness_factor = clamp(0.2 * depth * depth_to_blur, 0.0, 1.0);
depth = 0.0;

float world_to_texture = xyPerspectiveBias1 / perspective_factor / perspective_factor
* f_textureresolution / 2.0 / f_shadowfar;
float world_to_texture = f_textureresolution / 2. / shadowCascades[cascade].boundary;
float world_radius = 0.2; // shadow blur radius in world float coordinates, e.g. 0.2 = 0.02 of one node
float base_radius = max(BASEFILTERRADIUS, SOFTSHADOWRADIUS / 5.);

return max(BASEFILTERRADIUS * f_textureresolution / 4096.0, sharpness_factor * world_radius * world_to_texture * SOFTSHADOWRADIUS);
return max(base_radius, sharpness_factor * world_radius * world_to_texture * SOFTSHADOWRADIUS);
}

#ifdef POISSON_FILTER
Expand Down Expand Up @@ -240,9 +318,13 @@ const vec2[64] poissonDisk = vec2[64](
);

#ifdef COLORED_SHADOWS

vec4 getShadowColor(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
{
#if SHADOW_FILTER == 0
return getHardShadowColor(shadowsampler, smTexCoord, realDistance);
#elif SHADOW_FILTER == 1
return getFilteredShadowColor(shadowsampler, smTexCoord, realDistance);
#else
float radius = getPenumbraRadius(shadowsampler, smTexCoord, realDistance);
if (radius < 0.1) {
// we are in the middle of even brightness, no need for filtering
Expand All @@ -264,12 +346,18 @@ vec4 getShadowColor(sampler2D shadowsampler, vec2 smTexCoord, float realDistance
}

return visibility / samples;
#endif
}

#else

float getShadow(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
{
#if SHADOW_FILTER == 0
return getHardShadow(shadowsampler, smTexCoord, realDistance);
#elif SHADOW_FILTER == 1
return getFilteredShadow(shadowsampler, smTexCoord, realDistance);
#else
float radius = getPenumbraRadius(shadowsampler, smTexCoord, realDistance);
if (radius < 0.1) {
// we are in the middle of even brightness, no need for filtering
Expand All @@ -291,6 +379,7 @@ float getShadow(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
}

return visibility / samples;
#endif
}

#endif
Expand All @@ -302,6 +391,11 @@ float getShadow(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)

vec4 getShadowColor(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
{
#if SHADOW_FILTER == 0
return getHardShadowColor(shadowsampler, smTexCoord, realDistance);
#elif SHADOW_FILTER == 1
return getFilteredShadowColor(shadowsampler, smTexCoord, realDistance);
#else
float radius = getPenumbraRadius(shadowsampler, smTexCoord, realDistance);
if (radius < 0.1) {
// we are in the middle of even brightness, no need for filtering
Expand All @@ -325,11 +419,17 @@ vec4 getShadowColor(sampler2D shadowsampler, vec2 smTexCoord, float realDistance
}

return visibility / max(n, 1.0);
#endif
}

#else
float getShadow(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
{
#if SHADOW_FILTER == 0
return getHardShadow(shadowsampler, smTexCoord, realDistance);
#elif SHADOW_FILTER == 1
return getFilteredShadow(shadowsampler, smTexCoord, realDistance);
#else
float radius = getPenumbraRadius(shadowsampler, smTexCoord, realDistance);
if (radius < 0.1) {
// we are in the middle of even brightness, no need for filtering
Expand All @@ -353,6 +453,7 @@ float getShadow(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
}

return visibility / max(n, 1.0);
#endif
}

#endif
Expand Down Expand Up @@ -385,15 +486,23 @@ void main(void)
if (f_shadow_strength > 0.0) {
float shadow_int = 0.0;
vec3 shadow_color = vec3(0.0, 0.0, 0.0);
vec3 posLightSpace = getLightSpacePosition();

float distance_rate = (1.0 - pow(clamp(2.0 * length(posLightSpace.xy - 0.5),0.0,1.0), 10.0));
if (max(abs(posLightSpace.x - 0.5), abs(posLightSpace.y - 0.5)) > 0.5)
distance_rate = 0.0;
vec3 posLightSpace = getLightSpacePosition(cascade); // 0..1 within a single cascade in the shadow map

float distance_rate = 1.0;
if (cascade == cascadeCount - 1) {
distance_rate = (1.0 - pow(clamp(2.0 * length(posLightSpace.xy - 0.5),0.0,1.0), 10.0));
if (max(abs(posLightSpace.x - 0.5), abs(posLightSpace.y - 0.5)) > 0.5)
distance_rate = 0.0;
}

float f_adj_shadow_strength = max(adj_shadow_strength - mtsmoothstep(0.9, 1.1, posLightSpace.z),0.0);

if (distance_rate > 1e-7) {

// shift posLightSpace to the right cascade in the shadow map
posLightSpace.x = (posLightSpace.x + float(cascade)) / cascadeCount;

#ifdef COLORED_SHADOWS
vec4 visibility;
if (cosLight > 0.0 || f_normal_length < 1e-3)
Expand Down Expand Up @@ -434,6 +543,7 @@ void main(void)
(1.0 - adjusted_night_ratio) * ( // natural light
col.rgb * (1.0 - shadow_int * (1.0 - shadow_color)) + // filtered texture color
dayLight * shadow_color * shadow_int); // reflected filtered sunlight/moonlight

}
#endif

Expand Down