Implement shadow offsets for the new SM distortion function (#12191)

* Move shadow position calculation to vertex shaders
* Animate entire scene before rendering shadows to prevent lagging of shadows
* Remove unnecessary use of PolygonOffsetFactor
* Apply normal offset to both nodes and objects
* Rename getPerspectiveFactor -> applyPerspectiveDistortion
* Remove perspective distortion from fragment shaders
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x2048 2022-04-14 22:49:30 +02:00 committed by GitHub
parent 9aabd911eb
commit a5d29fa1d4
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9 changed files with 184 additions and 122 deletions

@ -18,10 +18,13 @@ uniform float animationTimer;
uniform float f_shadowfar;
uniform float f_shadow_strength;
uniform vec4 CameraPos;
varying float normalOffsetScale;
uniform float xyPerspectiveBias0;
uniform float xyPerspectiveBias1;
varying float adj_shadow_strength;
varying float cosLight;
varying float f_normal_length;
varying vec3 shadow_position;
#endif
@ -45,24 +48,7 @@ varying float nightRatio;
const float fogStart = FOG_START;
const float fogShadingParameter = 1.0 / ( 1.0 - fogStart);
#ifdef ENABLE_DYNAMIC_SHADOWS
uniform float xyPerspectiveBias0;
uniform float xyPerspectiveBias1;
uniform float zPerspectiveBias;
vec4 getPerspectiveFactor(in vec4 shadowPosition)
{
vec2 s = vec2(shadowPosition.x > CameraPos.x ? 1.0 : -1.0, shadowPosition.y > CameraPos.y ? 1.0 : -1.0);
vec2 l = s * (shadowPosition.xy - CameraPos.xy) / (1.0 - s * CameraPos.xy);
float pDistance = length(l);
float pFactor = pDistance * xyPerspectiveBias0 + xyPerspectiveBias1;
l /= pFactor;
shadowPosition.xy = CameraPos.xy * (1.0 - l) + s * l;
shadowPosition.z *= zPerspectiveBias;
return shadowPosition;
}
// assuming near is always 1.0
float getLinearDepth()
@ -72,15 +58,7 @@ float getLinearDepth()
vec3 getLightSpacePosition()
{
vec4 pLightSpace;
// some drawtypes have zero normals, so we need to handle it :(
#if DRAW_TYPE == NDT_PLANTLIKE
pLightSpace = m_ShadowViewProj * vec4(worldPosition, 1.0);
#else
pLightSpace = m_ShadowViewProj * vec4(worldPosition + normalOffsetScale * normalize(vNormal), 1.0);
#endif
pLightSpace = getPerspectiveFactor(pLightSpace);
return pLightSpace.xyz * 0.5 + 0.5;
return shadow_position * 0.5 + 0.5;
}
// custom smoothstep implementation because it's not defined in glsl1.2
// https://docs.gl/sl4/smoothstep
@ -499,14 +477,14 @@ void main(void)
#ifdef COLORED_SHADOWS
vec4 visibility;
if (cosLight > 0.0)
if (cosLight > 0.0 || f_normal_length < 1e-3)
visibility = getShadowColor(ShadowMapSampler, posLightSpace.xy, posLightSpace.z);
else
visibility = vec4(1.0, 0.0, 0.0, 0.0);
shadow_int = visibility.r;
shadow_color = visibility.gba;
#else
if (cosLight > 0.0)
if (cosLight > 0.0 || f_normal_length < 1e-3)
shadow_int = getShadow(ShadowMapSampler, posLightSpace.xy, posLightSpace.z);
else
shadow_int = 1.0;

@ -32,10 +32,13 @@ centroid varying vec2 varTexCoord;
uniform float f_shadowfar;
uniform float f_shadow_strength;
uniform float f_timeofday;
uniform vec4 CameraPos;
varying float cosLight;
varying float normalOffsetScale;
varying float adj_shadow_strength;
varying float f_normal_length;
varying vec3 shadow_position;
#endif
@ -47,8 +50,36 @@ const float e = 2.718281828459;
const float BS = 10.0;
uniform float xyPerspectiveBias0;
uniform float xyPerspectiveBias1;
uniform float zPerspectiveBias;
#ifdef ENABLE_DYNAMIC_SHADOWS
vec4 getRelativePosition(in vec4 position)
{
vec2 l = position.xy - CameraPos.xy;
vec2 s = l / abs(l);
s = (1.0 - s * CameraPos.xy);
l /= s;
return vec4(l, s);
}
float getPerspectiveFactor(in vec4 relativePosition)
{
float pDistance = length(relativePosition.xy);
float pFactor = pDistance * xyPerspectiveBias0 + xyPerspectiveBias1;
return pFactor;
}
vec4 applyPerspectiveDistortion(in vec4 position)
{
vec4 l = getRelativePosition(position);
float pFactor = getPerspectiveFactor(l);
l.xy /= pFactor;
position.xy = l.xy * l.zw + CameraPos.xy;
position.z *= zPerspectiveBias;
return position;
}
// custom smoothstep implementation because it's not defined in glsl1.2
// https://docs.gl/sl4/smoothstep
float mtsmoothstep(in float edge0, in float edge1, in float x)
@ -196,21 +227,32 @@ void main(void)
#ifdef ENABLE_DYNAMIC_SHADOWS
if (f_shadow_strength > 0.0) {
vec3 nNormal = normalize(vNormal);
cosLight = dot(nNormal, -v_LightDirection);
vec3 nNormal;
f_normal_length = length(vNormal);
// Calculate normal offset scale based on the texel size adjusted for
// curvature of the SM texture. This code must be change together with
// getPerspectiveFactor or any light-space transformation.
vec3 eyeToVertex = worldPosition - eyePosition + cameraOffset;
// Distance from the vertex to the player
float distanceToPlayer = length(eyeToVertex - v_LightDirection * dot(eyeToVertex, v_LightDirection)) / f_shadowfar;
// perspective factor estimation according to the
float perspectiveFactor = distanceToPlayer * xyPerspectiveBias0 + xyPerspectiveBias1;
float texelSize = f_shadowfar * perspectiveFactor * perspectiveFactor /
(f_textureresolution * xyPerspectiveBias1 - perspectiveFactor * xyPerspectiveBias0);
float slopeScale = clamp(pow(1.0 - cosLight*cosLight, 0.5), 0.0, 1.0);
normalOffsetScale = texelSize * slopeScale;
/* normalOffsetScale is in world coordinates (1/10th of a meter)
z_bias is in light space coordinates */
float normalOffsetScale, z_bias;
float pFactor = getPerspectiveFactor(getRelativePosition(m_ShadowViewProj * mWorld * inVertexPosition));
if (f_normal_length > 0.0) {
nNormal = normalize(vNormal);
cosLight = dot(nNormal, -v_LightDirection);
float sinLight = pow(1 - pow(cosLight, 2.0), 0.5);
normalOffsetScale = 2.0 * pFactor * pFactor * sinLight * min(f_shadowfar, 500.0) /
xyPerspectiveBias1 / f_textureresolution;
z_bias = 1.0 * sinLight / cosLight;
}
else {
nNormal = vec3(0.0);
cosLight = clamp(dot(v_LightDirection, normalize(vec3(v_LightDirection.x, 0.0, v_LightDirection.z))), 1e-2, 1.0);
float sinLight = pow(1 - pow(cosLight, 2.0), 0.5);
normalOffsetScale = 0.0;
z_bias = 3.6e3 * sinLight / cosLight;
}
z_bias *= pFactor * pFactor / f_textureresolution / f_shadowfar;
shadow_position = applyPerspectiveDistortion(m_ShadowViewProj * mWorld * (inVertexPosition + vec4(normalOffsetScale * nNormal, 0.0))).xyz;
shadow_position.z -= z_bias;
if (f_timeofday < 0.2) {
adj_shadow_strength = f_shadow_strength * 0.5 *
@ -223,7 +265,6 @@ void main(void)
mtsmoothstep(0.20, 0.25, f_timeofday) *
(1.0 - mtsmoothstep(0.7, 0.8, f_timeofday));
}
f_normal_length = length(vNormal);
}
#endif
}

@ -19,10 +19,13 @@ uniform float animationTimer;
uniform float f_shadowfar;
uniform float f_shadow_strength;
uniform vec4 CameraPos;
varying float normalOffsetScale;
uniform float xyPerspectiveBias0;
uniform float xyPerspectiveBias1;
varying float adj_shadow_strength;
varying float cosLight;
varying float f_normal_length;
varying vec3 shadow_position;
#endif
@ -48,24 +51,7 @@ varying float vIDiff;
const float fogStart = FOG_START;
const float fogShadingParameter = 1.0 / (1.0 - fogStart);
#ifdef ENABLE_DYNAMIC_SHADOWS
uniform float xyPerspectiveBias0;
uniform float xyPerspectiveBias1;
uniform float zPerspectiveBias;
vec4 getPerspectiveFactor(in vec4 shadowPosition)
{
vec2 s = vec2(shadowPosition.x > CameraPos.x ? 1.0 : -1.0, shadowPosition.y > CameraPos.y ? 1.0 : -1.0);
vec2 l = s * (shadowPosition.xy - CameraPos.xy) / (1.0 - s * CameraPos.xy);
float pDistance = length(l);
float pFactor = pDistance * xyPerspectiveBias0 + xyPerspectiveBias1;
l /= pFactor;
shadowPosition.xy = CameraPos.xy * (1.0 - l) + s * l;
shadowPosition.z *= zPerspectiveBias;
return shadowPosition;
}
// assuming near is always 1.0
float getLinearDepth()
@ -75,15 +61,7 @@ float getLinearDepth()
vec3 getLightSpacePosition()
{
vec4 pLightSpace;
// some drawtypes have zero normals, so we need to handle it :(
#if DRAW_TYPE == NDT_PLANTLIKE
pLightSpace = m_ShadowViewProj * vec4(worldPosition, 1.0);
#else
pLightSpace = m_ShadowViewProj * vec4(worldPosition + normalOffsetScale * normalize(vNormal), 1.0);
#endif
pLightSpace = getPerspectiveFactor(pLightSpace);
return pLightSpace.xyz * 0.5 + 0.5;
return shadow_position * 0.5 + 0.5;
}
// custom smoothstep implementation because it's not defined in glsl1.2
// https://docs.gl/sl4/smoothstep
@ -503,13 +481,14 @@ void main(void)
#ifdef COLORED_SHADOWS
vec4 visibility;
if (cosLight > 0.0)
if (cosLight > 0.0 || f_normal_length < 1e-3)
visibility = getShadowColor(ShadowMapSampler, posLightSpace.xy, posLightSpace.z);
else
visibility = vec4(1.0, 0.0, 0.0, 0.0);
shadow_int = visibility.r;
shadow_color = visibility.gba;
#else
if (cosLight > 0.0 || f_normal_length < 1e-3)
if (cosLight > 0.0)
shadow_int = getShadow(ShadowMapSampler, posLightSpace.xy, posLightSpace.z);
else

@ -24,10 +24,12 @@ centroid varying vec2 varTexCoord;
uniform float f_shadowfar;
uniform float f_shadow_strength;
uniform float f_timeofday;
uniform vec4 CameraPos;
varying float cosLight;
varying float normalOffsetScale;
varying float adj_shadow_strength;
varying float f_normal_length;
varying vec3 shadow_position;
#endif
varying vec3 eyeVec;
@ -39,8 +41,36 @@ const float e = 2.718281828459;
const float BS = 10.0;
uniform float xyPerspectiveBias0;
uniform float xyPerspectiveBias1;
uniform float zPerspectiveBias;
#ifdef ENABLE_DYNAMIC_SHADOWS
vec4 getRelativePosition(in vec4 position)
{
vec2 l = position.xy - CameraPos.xy;
vec2 s = l / abs(l);
s = (1.0 - s * CameraPos.xy);
l /= s;
return vec4(l, s);
}
float getPerspectiveFactor(in vec4 relativePosition)
{
float pDistance = length(relativePosition.xy);
float pFactor = pDistance * xyPerspectiveBias0 + xyPerspectiveBias1;
return pFactor;
}
vec4 applyPerspectiveDistortion(in vec4 position)
{
vec4 l = getRelativePosition(position);
float pFactor = getPerspectiveFactor(l);
l.xy /= pFactor;
position.xy = l.xy * l.zw + CameraPos.xy;
position.z *= zPerspectiveBias;
return position;
}
// custom smoothstep implementation because it's not defined in glsl1.2
// https://docs.gl/sl4/smoothstep
float mtsmoothstep(in float edge0, in float edge1, in float x)
@ -107,20 +137,31 @@ void main(void)
#ifdef ENABLE_DYNAMIC_SHADOWS
if (f_shadow_strength > 0.0) {
vec3 nNormal = normalize(vNormal);
cosLight = dot(nNormal, -v_LightDirection);
f_normal_length = length(vNormal);
// Calculate normal offset scale based on the texel size adjusted for
// curvature of the SM texture. This code must be change together with
// getPerspectiveFactor or any light-space transformation.
vec3 eyeToVertex = worldPosition - eyePosition + cameraOffset;
// Distance from the vertex to the player
float distanceToPlayer = length(eyeToVertex - v_LightDirection * dot(eyeToVertex, v_LightDirection)) / f_shadowfar;
// perspective factor estimation according to the
float perspectiveFactor = distanceToPlayer * xyPerspectiveBias0 + xyPerspectiveBias1;
float texelSize = f_shadowfar * perspectiveFactor * perspectiveFactor /
(f_textureresolution * xyPerspectiveBias1 - perspectiveFactor * xyPerspectiveBias0);
float slopeScale = clamp(pow(1.0 - cosLight*cosLight, 0.5), 0.0, 1.0);
normalOffsetScale = texelSize * slopeScale;
/* normalOffsetScale is in world coordinates (1/10th of a meter)
z_bias is in light space coordinates */
float normalOffsetScale, z_bias;
float pFactor = getPerspectiveFactor(getRelativePosition(m_ShadowViewProj * mWorld * inVertexPosition));
if (f_normal_length > 0.0) {
nNormal = normalize(vNormal);
cosLight = dot(nNormal, -v_LightDirection);
float sinLight = pow(1 - pow(cosLight, 2.0), 0.5);
normalOffsetScale = 0.1 * pFactor * pFactor * sinLight * min(f_shadowfar, 500.0) /
xyPerspectiveBias1 / f_textureresolution;
z_bias = 1e3 * sinLight / cosLight * (0.5 + f_textureresolution / 1024.0);
}
else {
nNormal = vec3(0.0);
cosLight = clamp(dot(v_LightDirection, normalize(vec3(v_LightDirection.x, 0.0, v_LightDirection.z))), 1e-2, 1.0);
float sinLight = pow(1 - pow(cosLight, 2.0), 0.5);
normalOffsetScale = 0.0;
z_bias = 3.6e3 * sinLight / cosLight;
}
z_bias *= pFactor * pFactor / f_textureresolution / f_shadowfar;
shadow_position = applyPerspectiveDistortion(m_ShadowViewProj * mWorld * (inVertexPosition + vec4(normalOffsetScale * nNormal, 0.0))).xyz;
shadow_position.z -= z_bias;
if (f_timeofday < 0.2) {
adj_shadow_strength = f_shadow_strength * 0.5 *
@ -133,7 +174,6 @@ void main(void)
mtsmoothstep(0.20, 0.25, f_timeofday) *
(1.0 - mtsmoothstep(0.7, 0.8, f_timeofday));
}
f_normal_length = length(vNormal);
}
#endif
}

@ -9,24 +9,37 @@ uniform float xyPerspectiveBias0;
uniform float xyPerspectiveBias1;
uniform float zPerspectiveBias;
vec4 getPerspectiveFactor(in vec4 shadowPosition)
vec4 getRelativePosition(in vec4 position)
{
vec2 s = vec2(shadowPosition.x > CameraPos.x ? 1.0 : -1.0, shadowPosition.y > CameraPos.y ? 1.0 : -1.0);
vec2 l = s * (shadowPosition.xy - CameraPos.xy) / (1.0 - s * CameraPos.xy);
float pDistance = length(l);
float pFactor = pDistance * xyPerspectiveBias0 + xyPerspectiveBias1;
l /= pFactor;
shadowPosition.xy = CameraPos.xy * (1.0 - l) + s * l;
shadowPosition.z *= zPerspectiveBias;
return shadowPosition;
vec2 l = position.xy - CameraPos.xy;
vec2 s = l / abs(l);
s = (1.0 - s * CameraPos.xy);
l /= s;
return vec4(l, s);
}
float getPerspectiveFactor(in vec4 relativePosition)
{
float pDistance = length(relativePosition.xy);
float pFactor = pDistance * xyPerspectiveBias0 + xyPerspectiveBias1;
return pFactor;
}
vec4 applyPerspectiveDistortion(in vec4 position)
{
vec4 l = getRelativePosition(position);
float pFactor = getPerspectiveFactor(l);
l.xy /= pFactor;
position.xy = l.xy * l.zw + CameraPos.xy;
position.z *= zPerspectiveBias;
return position;
}
void main()
{
vec4 pos = LightMVP * gl_Vertex;
tPos = getPerspectiveFactor(LightMVP * gl_Vertex);
tPos = applyPerspectiveDistortion(LightMVP * gl_Vertex);
gl_Position = vec4(tPos.xyz, 1.0);
gl_TexCoord[0].st = gl_MultiTexCoord0.st;

@ -6,24 +6,37 @@ uniform float xyPerspectiveBias0;
uniform float xyPerspectiveBias1;
uniform float zPerspectiveBias;
vec4 getPerspectiveFactor(in vec4 shadowPosition)
vec4 getRelativePosition(in vec4 position)
{
vec2 s = vec2(shadowPosition.x > CameraPos.x ? 1.0 : -1.0, shadowPosition.y > CameraPos.y ? 1.0 : -1.0);
vec2 l = s * (shadowPosition.xy - CameraPos.xy) / (1.0 - s * CameraPos.xy);
float pDistance = length(l);
float pFactor = pDistance * xyPerspectiveBias0 + xyPerspectiveBias1;
l /= pFactor;
shadowPosition.xy = CameraPos.xy * (1.0 - l) + s * l;
shadowPosition.z *= zPerspectiveBias;
return shadowPosition;
vec2 l = position.xy - CameraPos.xy;
vec2 s = l / abs(l);
s = (1.0 - s * CameraPos.xy);
l /= s;
return vec4(l, s);
}
float getPerspectiveFactor(in vec4 relativePosition)
{
float pDistance = length(relativePosition.xy);
float pFactor = pDistance * xyPerspectiveBias0 + xyPerspectiveBias1;
return pFactor;
}
vec4 applyPerspectiveDistortion(in vec4 position)
{
vec4 l = getRelativePosition(position);
float pFactor = getPerspectiveFactor(l);
l.xy /= pFactor;
position.xy = l.xy * l.zw + CameraPos.xy;
position.z *= zPerspectiveBias;
return position;
}
void main()
{
vec4 pos = LightMVP * gl_Vertex;
tPos = getPerspectiveFactor(pos);
tPos = applyPerspectiveDistortion(pos);
gl_Position = vec4(tPos.xyz, 1.0);
gl_TexCoord[0] = gl_TextureMatrix[0] * gl_MultiTexCoord0;

@ -76,8 +76,11 @@ void RenderingCore::draw(video::SColor _skycolor, bool _show_hud, bool _show_min
draw_wield_tool = _draw_wield_tool;
draw_crosshair = _draw_crosshair;
if (shadow_renderer)
if (shadow_renderer) {
// This is necessary to render shadows for animations correctly
smgr->getRootSceneNode()->OnAnimate(device->getTimer()->getTime());
shadow_renderer->update();
}
beforeDraw();
drawAll();

@ -69,12 +69,18 @@ public:
const core::matrix4 &getFutureProjectionMatrix() const;
core::matrix4 getViewProjMatrix();
/// Gets the light's far value.
/// Gets the light's maximum far value, i.e. the shadow boundary
f32 getMaxFarValue() const
{
return farPlane * BS;
}
/// Gets the current far value of the light
f32 getFarValue() const
{
return shadow_frustum.zFar;
}
/// Gets the light's color.
const video::SColorf &getLightColor() const

@ -143,7 +143,7 @@ size_t ShadowRenderer::getDirectionalLightCount() const
f32 ShadowRenderer::getMaxShadowFar() const
{
if (!m_light_list.empty()) {
float zMax = m_light_list[0].getMaxFarValue();
float zMax = m_light_list[0].getFarValue();
return zMax;
}
return 0.0f;
@ -418,10 +418,6 @@ void ShadowRenderer::renderShadowMap(video::ITexture *target,
material.BackfaceCulling = false;
material.FrontfaceCulling = true;
material.PolygonOffsetFactor = 4.0f;
material.PolygonOffsetDirection = video::EPO_BACK;
//material.PolygonOffsetDepthBias = 1.0f/4.0f;
//material.PolygonOffsetSlopeScale = -1.f;
if (m_shadow_map_colored && pass != scene::ESNRP_SOLID) {
material.MaterialType = (video::E_MATERIAL_TYPE) depth_shader_trans;
@ -431,9 +427,6 @@ void ShadowRenderer::renderShadowMap(video::ITexture *target,
material.BlendOperation = video::EBO_MIN;
}
// FIXME: I don't think this is needed here
map_node->OnAnimate(m_device->getTimer()->getTime());
m_driver->setTransform(video::ETS_WORLD,
map_node->getAbsoluteTransformation());
@ -479,10 +472,6 @@ void ShadowRenderer::renderShadowObjects(
current_mat.BackfaceCulling = true;
current_mat.FrontfaceCulling = false;
current_mat.PolygonOffsetFactor = 1.0f/2048.0f;
current_mat.PolygonOffsetDirection = video::EPO_BACK;
//current_mat.PolygonOffsetDepthBias = 1.0 * 2.8e-6;
//current_mat.PolygonOffsetSlopeScale = -1.f;
}
m_driver->setTransform(video::ETS_WORLD,