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Improve shadow filters (#12195)
* Rewrite shadow filtering for the new distortion * Calculate penumbra radius using a single sample * Avoid peter-panning effect due to filtering of short shadows * Add adaptive filter quality for soft shadows * Avoid sharp shadows on surfaces without normals (e.g. plants) * Increase default and maximum soft shadow radius * Make line numbers in shader errors match the code
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9 changed files with 131 additions and 220 deletions
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@ -25,6 +25,7 @@ uniform float animationTimer;
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varying float cosLight;
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varying float f_normal_length;
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varying vec3 shadow_position;
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varying float perspective_factor;
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#endif
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@ -116,23 +117,16 @@ float getHardShadow(sampler2D shadowsampler, vec2 smTexCoord, float realDistance
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#if SHADOW_FILTER == 2
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#define PCFBOUND 3.5
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#define PCFSAMPLES 64.0
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#define PCFBOUND 2.0 // 5x5
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#define PCFSAMPLES 25
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#elif SHADOW_FILTER == 1
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#define PCFBOUND 1.5
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#if defined(POISSON_FILTER)
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#define PCFSAMPLES 32.0
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#else
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#define PCFSAMPLES 16.0
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#endif
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#define PCFBOUND 1.0 // 3x3
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#define PCFSAMPLES 9
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#else
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#define PCFBOUND 0.0
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#if defined(POISSON_FILTER)
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#define PCFSAMPLES 4.0
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#else
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#define PCFSAMPLES 1.0
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#endif
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#define PCFSAMPLES 1
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#endif
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#ifdef COLORED_SHADOWS
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float getHardShadowDepth(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
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{
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@ -149,59 +143,31 @@ float getHardShadowDepth(sampler2D shadowsampler, vec2 smTexCoord, float realDis
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}
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#endif
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float getBaseLength(vec2 smTexCoord)
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{
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float l = length(2.0 * smTexCoord.xy - 1.0 - CameraPos.xy); // length in texture coords
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return xyPerspectiveBias1 / (1.0 / l - xyPerspectiveBias0); // return to undistorted coords
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}
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#define BASEFILTERRADIUS 1.0
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float getDeltaPerspectiveFactor(float l)
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float getPenumbraRadius(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
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{
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return 0.04 * pow(512.0 / f_textureresolution, 0.4) / (xyPerspectiveBias0 * l + xyPerspectiveBias1); // original distortion factor, divided by 10
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}
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float getPenumbraRadius(sampler2D shadowsampler, vec2 smTexCoord, float realDistance, float multiplier)
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{
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float baseLength = getBaseLength(smTexCoord);
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float perspectiveFactor;
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// Return fast if sharp shadows are requested
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if (PCFBOUND == 0.0)
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if (PCFBOUND == 0.0 || SOFTSHADOWRADIUS <= 0.0)
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return 0.0;
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if (SOFTSHADOWRADIUS <= 1.0) {
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perspectiveFactor = getDeltaPerspectiveFactor(baseLength);
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return max(2 * length(smTexCoord.xy) * 2048 / f_textureresolution / pow(perspectiveFactor, 3), SOFTSHADOWRADIUS);
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}
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vec2 clampedpos;
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float texture_size = 1.0 / (2048 /*f_textureresolution*/ * 0.5);
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float y, x;
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float depth = 0.0;
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float pointDepth;
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float maxRadius = SOFTSHADOWRADIUS * 5.0 * multiplier;
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float depth = getHardShadowDepth(shadowsampler, smTexCoord.xy, realDistance);
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// A factor from 0 to 1 to reduce blurring of short shadows
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float sharpness_factor = 1.0;
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// conversion factor from shadow depth to blur radius
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float depth_to_blur = f_shadowfar / SOFTSHADOWRADIUS / xyPerspectiveBias0;
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if (depth > 0.0 && f_normal_length > 0.0)
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// 5 is empirical factor that controls how fast shadow loses sharpness
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sharpness_factor = clamp(5 * depth * depth_to_blur, 0.0, 1.0);
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depth = 0.0;
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float bound = clamp(PCFBOUND * (1 - baseLength), 0.0, PCFBOUND);
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int n = 0;
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float world_to_texture = xyPerspectiveBias1 / perspective_factor / perspective_factor
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* f_textureresolution / 2.0 / f_shadowfar;
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float world_radius = 0.2; // shadow blur radius in world float coordinates, e.g. 0.2 = 0.02 of one node
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for (y = -bound; y <= bound; y += 1.0)
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for (x = -bound; x <= bound; x += 1.0) {
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clampedpos = vec2(x,y);
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perspectiveFactor = getDeltaPerspectiveFactor(baseLength + length(clampedpos) * texture_size * maxRadius);
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clampedpos = clampedpos * texture_size * perspectiveFactor * maxRadius * perspectiveFactor + smTexCoord.xy;
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pointDepth = getHardShadowDepth(shadowsampler, clampedpos.xy, realDistance);
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if (pointDepth > -0.01) {
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depth += pointDepth;
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n += 1;
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}
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}
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depth = depth / n;
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depth = pow(clamp(depth, 0.0, 1000.0), 1.6) / 0.001;
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perspectiveFactor = getDeltaPerspectiveFactor(baseLength);
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return max(length(smTexCoord.xy) * 2 * 2048 / f_textureresolution / pow(perspectiveFactor, 3), depth * maxRadius);
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return max(BASEFILTERRADIUS * f_textureresolution / 4096.0, sharpness_factor * world_radius * world_to_texture * SOFTSHADOWRADIUS);
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}
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#ifdef POISSON_FILTER
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@ -276,26 +242,23 @@ const vec2[64] poissonDisk = vec2[64](
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vec4 getShadowColor(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
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{
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vec2 clampedpos;
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vec4 visibility = vec4(0.0);
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float radius = getPenumbraRadius(shadowsampler, smTexCoord, realDistance, 1.5); // scale to align with PCF
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float radius = getPenumbraRadius(shadowsampler, smTexCoord, realDistance);
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if (radius < 0.1) {
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// we are in the middle of even brightness, no need for filtering
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return getHardShadowColor(shadowsampler, smTexCoord.xy, realDistance);
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}
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float baseLength = getBaseLength(smTexCoord);
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float perspectiveFactor;
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vec2 clampedpos;
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vec4 visibility = vec4(0.0);
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float scale_factor = radius / f_textureresolution;
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float texture_size = 1.0 / (f_textureresolution * 0.5);
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int samples = int(clamp(PCFSAMPLES * (1 - baseLength) * (1 - baseLength), PCFSAMPLES / 4, PCFSAMPLES));
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int samples = (1 + 1 * int(SOFTSHADOWRADIUS > 1.0)) * PCFSAMPLES; // scale max samples for the soft shadows
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samples = int(clamp(pow(4.0 * radius + 1.0, 2.0), 1.0, float(samples)));
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int init_offset = int(floor(mod(((smTexCoord.x * 34.0) + 1.0) * smTexCoord.y, 64.0-samples)));
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int end_offset = int(samples) + init_offset;
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for (int x = init_offset; x < end_offset; x++) {
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clampedpos = poissonDisk[x];
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perspectiveFactor = getDeltaPerspectiveFactor(baseLength + length(clampedpos) * texture_size * radius);
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clampedpos = clampedpos * texture_size * perspectiveFactor * radius * perspectiveFactor + smTexCoord.xy;
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clampedpos = poissonDisk[x] * scale_factor + smTexCoord.xy;
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visibility += getHardShadowColor(shadowsampler, clampedpos.xy, realDistance);
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}
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@ -306,26 +269,23 @@ vec4 getShadowColor(sampler2D shadowsampler, vec2 smTexCoord, float realDistance
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float getShadow(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
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{
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vec2 clampedpos;
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float visibility = 0.0;
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float radius = getPenumbraRadius(shadowsampler, smTexCoord, realDistance, 1.5); // scale to align with PCF
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float radius = getPenumbraRadius(shadowsampler, smTexCoord, realDistance);
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if (radius < 0.1) {
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// we are in the middle of even brightness, no need for filtering
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return getHardShadow(shadowsampler, smTexCoord.xy, realDistance);
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}
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float baseLength = getBaseLength(smTexCoord);
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float perspectiveFactor;
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vec2 clampedpos;
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float visibility = 0.0;
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float scale_factor = radius / f_textureresolution;
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float texture_size = 1.0 / (f_textureresolution * 0.5);
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int samples = int(clamp(PCFSAMPLES * (1 - baseLength) * (1 - baseLength), PCFSAMPLES / 4, PCFSAMPLES));
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int samples = (1 + 1 * int(SOFTSHADOWRADIUS > 1.0)) * PCFSAMPLES; // scale max samples for the soft shadows
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samples = int(clamp(pow(4.0 * radius + 1.0, 2.0), 1.0, float(samples)));
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int init_offset = int(floor(mod(((smTexCoord.x * 34.0) + 1.0) * smTexCoord.y, 64.0-samples)));
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int end_offset = int(samples) + init_offset;
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for (int x = init_offset; x < end_offset; x++) {
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clampedpos = poissonDisk[x];
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perspectiveFactor = getDeltaPerspectiveFactor(baseLength + length(clampedpos) * texture_size * radius);
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clampedpos = clampedpos * texture_size * perspectiveFactor * radius * perspectiveFactor + smTexCoord.xy;
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clampedpos = poissonDisk[x] * scale_factor + smTexCoord.xy;
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visibility += getHardShadow(shadowsampler, clampedpos.xy, realDistance);
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}
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@ -341,65 +301,57 @@ float getShadow(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
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vec4 getShadowColor(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
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{
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vec2 clampedpos;
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vec4 visibility = vec4(0.0);
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float radius = getPenumbraRadius(shadowsampler, smTexCoord, realDistance, 1.0);
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float radius = getPenumbraRadius(shadowsampler, smTexCoord, realDistance);
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if (radius < 0.1) {
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// we are in the middle of even brightness, no need for filtering
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return getHardShadowColor(shadowsampler, smTexCoord.xy, realDistance);
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}
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float baseLength = getBaseLength(smTexCoord);
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float perspectiveFactor;
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float texture_size = 1.0 / (f_textureresolution * 0.5);
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float y, x;
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float bound = clamp(PCFBOUND * (1 - baseLength), PCFBOUND / 2, PCFBOUND);
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int n = 0;
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vec2 clampedpos;
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vec4 visibility = vec4(0.0);
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float x, y;
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float bound = (1 + 0.5 * int(SOFTSHADOWRADIUS > 1.0)) * PCFBOUND; // scale max bound for soft shadows
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bound = clamp(0.5 * (4.0 * radius - 1.0), 0.5, bound);
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float scale_factor = radius / bound / f_textureresolution;
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float n = 0.0;
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// basic PCF filter
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for (y = -bound; y <= bound; y += 1.0)
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for (x = -bound; x <= bound; x += 1.0) {
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clampedpos = vec2(x,y); // screen offset
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perspectiveFactor = getDeltaPerspectiveFactor(baseLength + length(clampedpos) * texture_size * radius / bound);
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clampedpos = clampedpos * texture_size * perspectiveFactor * radius * perspectiveFactor / bound + smTexCoord.xy; // both dx,dy and radius are adjusted
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clampedpos = vec2(x,y) * scale_factor + smTexCoord.xy;
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visibility += getHardShadowColor(shadowsampler, clampedpos.xy, realDistance);
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n += 1;
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n += 1.0;
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}
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return visibility / n;
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return visibility / max(n, 1.0);
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}
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#else
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float getShadow(sampler2D shadowsampler, vec2 smTexCoord, float realDistance)
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{
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vec2 clampedpos;
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float visibility = 0.0;
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float radius = getPenumbraRadius(shadowsampler, smTexCoord, realDistance, 1.0);
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float radius = getPenumbraRadius(shadowsampler, smTexCoord, realDistance);
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if (radius < 0.1) {
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// we are in the middle of even brightness, no need for filtering
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return getHardShadow(shadowsampler, smTexCoord.xy, realDistance);
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}
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float baseLength = getBaseLength(smTexCoord);
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float perspectiveFactor;
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float texture_size = 1.0 / (f_textureresolution * 0.5);
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float y, x;
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float bound = clamp(PCFBOUND * (1 - baseLength), PCFBOUND / 2, PCFBOUND);
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int n = 0;
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vec2 clampedpos;
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float visibility = 0.0;
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float x, y;
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float bound = (1 + 0.5 * int(SOFTSHADOWRADIUS > 1.0)) * PCFBOUND; // scale max bound for soft shadows
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bound = clamp(0.5 * (4.0 * radius - 1.0), 0.5, bound);
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float scale_factor = radius / bound / f_textureresolution;
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float n = 0.0;
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// basic PCF filter
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for (y = -bound; y <= bound; y += 1.0)
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for (x = -bound; x <= bound; x += 1.0) {
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clampedpos = vec2(x,y); // screen offset
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perspectiveFactor = getDeltaPerspectiveFactor(baseLength + length(clampedpos) * texture_size * radius / bound);
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clampedpos = clampedpos * texture_size * perspectiveFactor * radius * perspectiveFactor / bound + smTexCoord.xy; // both dx,dy and radius are adjusted
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clampedpos = vec2(x,y) * scale_factor + smTexCoord.xy;
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visibility += getHardShadow(shadowsampler, clampedpos.xy, realDistance);
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n += 1;
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n += 1.0;
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}
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return visibility / n;
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return visibility / max(n, 1.0);
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}
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#endif
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