Mirrors/overte-HifiExperiments
3
0
Fork 0
mirror of https://github.com/HifiExperiments/overte.git synced 2025-08-16 19:33:14 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

First alpha version of cascade selection code in shader

Browse source
This commit is contained in:
Olivier Prat 2017-11-13 15:56:11 +01:00
parent 7515c341ad
commit 28d46dc4a5
1 changed files with 32 additions and 20 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

52
libraries/render-utils/src/Shadow.slh
View file

@ -65,8 +65,13 @@ float evalShadowNoise(vec4 seed) {
return fract(sin(dot_product) * 43758.5453);
}
float evalShadowAttenuationPCF(int cascadeIndex, vec4 position, vec4 shadowTexcoord) {
struct ShadowSampleOffsets {
vec3 points[4];
};
ShadowSampleOffsets evalShadowFilterOffsets(vec4 position) {
float shadowScale = getShadowScale();
ShadowSampleOffsets offsets;
#if 0
// Pattern dithering in screen space
@ -83,19 +88,28 @@ float evalShadowAttenuationPCF(int cascadeIndex, vec4 position, vec4 shadowTexco
// Offset for efficient PCF, see http://http.developer.nvidia.com/GPUGems/gpugems_ch11.html
ivec2 offset = coords & ivec2(1,1);
offset.y = (offset.x+offset.y) & 1;
vec2 offsetF = vec2(offset);
float shadowAttenuation = (0.25 * (
fetchShadow(cascadeIndex, shadowTexcoord.xyz + shadowScale * vec3(offset + PCFkernel[0], 0.0)) +
fetchShadow(cascadeIndex, shadowTexcoord.xyz + shadowScale * vec3(offset + PCFkernel[1], 0.0)) +
fetchShadow(cascadeIndex, shadowTexcoord.xyz + shadowScale * vec3(offset + PCFkernel[2], 0.0)) +
fetchShadow(cascadeIndex, shadowTexcoord.xyz + shadowScale * vec3(offset + PCFkernel[3], 0.0))
));
offsets.points[0] = shadowScale * vec3(offset + PCFkernel[0], 0.0);
offsets.points[1] = shadowScale * vec3(offset + PCFkernel[1], 0.0);
offsets.points[2] = shadowScale * vec3(offset + PCFkernel[2], 0.0);
offsets.points[3] = shadowScale * vec3(offset + PCFkernel[3], 0.0);
return offsets;
}
float evalShadowAttenuationPCF(int cascadeIndex, ShadowSampleOffsets offsets, vec4 shadowTexcoord) {
float shadowAttenuation = 0.25 * (
fetchShadow(cascadeIndex, shadowTexcoord.xyz + offsets.points[0]) +
fetchShadow(cascadeIndex, shadowTexcoord.xyz + offsets.points[1]) +
fetchShadow(cascadeIndex, shadowTexcoord.xyz + offsets.points[2]) +
fetchShadow(cascadeIndex, shadowTexcoord.xyz + offsets.points[3])
);
return shadowAttenuation;
}
float evalShadowCascadeAttenuation(int cascadeIndex, vec4 position) {
float evalShadowCascadeAttenuation(int cascadeIndex, vec4 position, ShadowSampleOffsets offsets) {
vec4 shadowTexcoord = evalShadowTexcoord(cascadeIndex, position);
if (shadowTexcoord.x < 0.0 || shadowTexcoord.x > 1.0 ||
shadowTexcoord.y < 0.0 || shadowTexcoord.y > 1.0 ||
@ -103,10 +117,12 @@ float evalShadowCascadeAttenuation(int cascadeIndex, vec4 position) {
// If a point is not in the map, do not attenuate
return 1.0;
}
return evalShadowAttenuationPCF(cascadeIndex, position, shadowTexcoord);
return evalShadowAttenuationPCF(cascadeIndex, offsets, shadowTexcoord);
}
float evalShadowAttenuation(vec4 position) {
ShadowSampleOffsets offsets = evalShadowFilterOffsets(position);
// Cascade selection based on :
// https://msdn.microsoft.com/en-us/library/windows/desktop/ee416307(v=vs.85).aspx
vec4 currentPixelDepth = position.zzzz;
@ -116,17 +132,13 @@ float evalShadowAttenuation(vec4 position) {
getShadowCascadeMinDistance(2),
getShadowCascadeMinDistance(3)
);
vec4 comparison = vec4( currentPixelDepth > cascadeDepthLimits);
bvec4 comparison = greaterThan( currentPixelDepth, cascadeDepthLimits);
int cascadeCount = getShadowCascadeCount();
float fIndex = dot(
vec4( cascadeCount > 0, cascadeCount > 1, cascadeCount > 2, cascadeCount > 3),
comparison
);
fIndex = min( fIndex, cascadeCount-1 );
int currentCascadeIndex = int(fIndex);
return evalShadowCascadeAttenuation(currentCascadeIndex, position);
bvec4 cascadeCountMask = greaterThan(ivec4(cascadeCount), ivec4(0,1,2,3));
int cascadeIndex = int(dot(ivec4(cascadeCountMask), ivec4(comparison)));
cascadeIndex = min( cascadeIndex, cascadeCount-1 );
return evalShadowCascadeAttenuation(cascadeIndex, position, offsets);
}
<@endif@>