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shader plumbing for screen-space refraction

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In this PR, the filament side is missing, so we're outputting back.
But all codepaths in the shader are implemented:
 cubemap/screenspace, solid/thin
This commit is contained in:
Pixelflinger
2019-12-08 22:18:18 -08:00
committed by Mathias Agopian
parent f670472e55
commit 1ccae61d40
2 changed files with 30 additions and 30 deletions
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shaders/src/light_indirect.fs
+26 -27
View File
@@ -338,32 +338,18 @@ void applyRefraction(const PixelParams pixel,
inout vec3 color) {
// when reading from the cubemap, we are not pre-exposed so we apply iblLuminance
// which is not the case when we'll read from the screen-space buffer
float scale = frameUniforms.iblLuminance;
float perceptualRoughness = pixel.perceptualRoughness;
float eta0 = pixel.eta;
vec3 r = -shading_view;
#if defined(MATERIAL_HAS_ABSORPTION) && !defined(MATERIAL_HAS_THICKNESS)
vec3 T = 1.0 - pixel.absorption;
#if REFRACTION_MODE == REFRACTION_MODE_SCREEN_SPACE
float d = 1.0;
#endif
#endif
// for a sphere, with local refraction (i.e. screen space)
//const float thickness = 1.0;
//vec3 r = refract(v, n, eta);
//float d = thickness * dot(-n, r);
//vec3 n2 = -normalize(dot(-n, r) * r + n * 0.5);
//vec3 p = d * r; // sample screen space here
//r = refract(r, n2, 1.0 / eta);
// for a slab with local refraction (i.e. screen space)
//const float thickness = 1.0;
//vec3 r = refract(v, n, eta);
//float d = thickness / dot(-n, r);
//vec3 n2 = n;
//vec3 r = v;
//vec3 p = d * r; // sample screen space here
/* compute first interface refraction */
#if REFRACTION_TYPE == REFRACTION_TYPE_SOLID
// for a sphere, with light at infinity (i.e. cubemap)
r = refract(r, n0, eta0);
@@ -375,7 +361,8 @@ void applyRefraction(const PixelParams pixel,
#error "invalid REFRACTION_TYPE"
#endif
#if defined(MATERIAL_HAS_ABSORPTION) && defined(MATERIAL_HAS_THICKNESS)
/* compute transmission T and distance traveled d, if needed */
#if (defined(MATERIAL_HAS_ABSORPTION) || (REFRACTION_MODE == REFRACTION_MODE_SCREEN_SPACE)) && defined(MATERIAL_HAS_THICKNESS)
#if REFRACTION_TYPE == REFRACTION_TYPE_SOLID
float d = pixel.thickness * -N0oR;
#else
@@ -384,21 +371,33 @@ void applyRefraction(const PixelParams pixel,
float N0oR = dot(-n0, refract(r, n0, eta0));
float d = pixel.thickness / max(N0oR, 0.1);
#endif
#if defined(MATERIAL_HAS_ABSORPTION)
vec3 T = exp(-pixel.absorption * d);
#endif
#if REFRACTION_TYPE == REFRACTION_TYPE_SOLID
vec3 n1 = normalize(N0oR * r - n0 * 0.5);
float eta1 = 1.0 / eta0;
// note: Total Internal Reflection cannot happen in a sphere from an outside ray
r = refract(r, n1, eta1);
#endif
vec3 Ft = prefilteredRadiance(r, perceptualRoughness) * scale;
/* sample the cubemap or screen-space */
#if REFRACTION_MODE == REFRACTION_MODE_CUBEMAP
#if REFRACTION_TYPE == REFRACTION_TYPE_SOLID
// compute the direction of the output ray (needed for accessing the cubemap)
vec3 n1 = normalize(N0oR * r - n0 * 0.5);
float eta1 = 1.0 / eta0;
r = refract(r, n1, eta1);
#endif
vec3 Ft = prefilteredRadiance(r, perceptualRoughness) * frameUniforms.iblLuminance;
#else
// compute the point where the ray exists the medium, if needed
vec4 p = vec4(shading_position + r * d, 1.0);
vec3 Ft;
p = frameUniforms.clipFromWorldMatrix * p;
// TODO: sample screen-space at p
Ft = vec3(0.0);
#endif
// fresnel from the first interface
/* fresnel from the first interface */
Ft *= 1.0 - E;
/* apply absoption */
#if defined(MATERIAL_HAS_ABSORPTION)
Ft *= T;
#endif
tools/matc/src/matc/ParametersProcessor.cpp
+4 -3
View File
@@ -465,9 +465,10 @@ static bool processDomain(MaterialBuilder& builder, const JsonishValue& value) {
}
static bool processRefraction(MaterialBuilder& builder, const JsonishValue& value) {
static const std::unordered_map<std::string, MaterialBuilder::Refraction> strToEnum {
{ "none", MaterialBuilder::Refraction::NONE },
{ "cubemap", MaterialBuilder::Refraction::CUBEMAP },
static const std::unordered_map<std::string, MaterialBuilder::Refraction> strToEnum{
{ "none", MaterialBuilder::Refraction::NONE },
{ "cubemap", MaterialBuilder::Refraction::CUBEMAP },
{ "screenspace", MaterialBuilder::Refraction::SCREEN_SPACE },
};
auto jsonString = value.toJsonString();
if (!isStringValidEnum(strToEnum, jsonString->getString())) {