From 601bd5ba7a634eb5fd6f28a28b4337e450a0f710 Mon Sep 17 00:00:00 2001
From: Alexander Rose <alexander.rose@weirdbyte.de>
Date: Sat, 10 Dec 2022 21:47:16 -0800
Subject: [PATCH] improve impostor shaders
- fix sphere near-clipping with orthographic projection
- fix cylinder near-clipping
- add interior cylinder caps
---
CHANGELOG.md | 4 ++
src/mol-gl/shader/cylinders.frag.ts | 65 ++++++++++++++++++++---------
src/mol-gl/shader/cylinders.vert.ts | 5 ++-
src/mol-gl/shader/spheres.frag.ts | 52 +++++++++++------------
src/mol-gl/shader/spheres.vert.ts | 6 ++-
5 files changed, 82 insertions(+), 50 deletions(-)
diff --git a/CHANGELOG.md b/CHANGELOG.md
index a57fcc8af..8c92d6aa8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,10 @@ Note that since we don't clearly distinguish between a public and private interf
- Fix 'once' for animations of systems with many frames
- Better guard against issue (black fringes) with bumpiness in impostors
+- Improve impostor shaders
+ - Fix sphere near-clipping with orthographic projection
+ - Fix cylinder near-clipping
+ - Add interior cylinder caps
## [v3.26.0] - 2022-12-04
diff --git a/src/mol-gl/shader/cylinders.frag.ts b/src/mol-gl/shader/cylinders.frag.ts
index ba17705d7..775274255 100644
--- a/src/mol-gl/shader/cylinders.frag.ts
+++ b/src/mol-gl/shader/cylinders.frag.ts
@@ -33,7 +33,8 @@ uniform mat4 uInvView;
bool CylinderImpostor(
in vec3 rayOrigin, in vec3 rayDir,
in vec3 start, in vec3 end, in float radius,
- out vec4 intersection, out bool interior
+ out vec3 cameraNormal, out bool interior,
+ out vec3 viewPosition, out float fragmentDepth
){
vec3 ba = end - start;
vec3 oc = rayOrigin - start;
@@ -42,7 +43,7 @@ bool CylinderImpostor(
float bard = dot(ba, rayDir);
float baoc = dot(ba, oc);
- float k2 = baba - bard*bard;
+ float k2 = baba - bard * bard;
float k1 = baba * dot(oc, rayDir) - baoc * bard;
float k0 = baba * dot(oc, oc) - baoc * baoc - radius * radius * baba;
@@ -58,8 +59,10 @@ bool CylinderImpostor(
float y = baoc + t * bard;
if (y > 0.0 && y < baba) {
interior = false;
- intersection = vec4(t, (oc + t * rayDir - ba * y / baba) / radius);
- return true;
+ cameraNormal = (oc + t * rayDir - ba * y / baba) / radius;
+ viewPosition = (uView * vec4(rayOrigin + t * rayDir, 1.0)).xyz;
+ fragmentDepth = calcDepth(viewPosition);
+ if (fragmentDepth > 0.0) return true;
}
if (topCap && y < 0.0) {
@@ -67,16 +70,20 @@ bool CylinderImpostor(
t = -baoc / bard;
if (abs(k1 + k2 * t) < h) {
interior = false;
- intersection = vec4(t, ba * sign(y) / baba);
- return true;
+ cameraNormal = -ba / baba;
+ viewPosition = (uView * vec4(rayOrigin + t * rayDir, 1.0)).xyz;
+ fragmentDepth = calcDepth(viewPosition);
+ if (fragmentDepth > 0.0) return true;
}
} else if(bottomCap && y >= 0.0) {
// bottom cap
t = (baba - baoc) / bard;
if (abs(k1 + k2 * t) < h) {
interior = false;
- intersection = vec4(t, ba * sign(y) / baba);
- return true;
+ cameraNormal = ba / baba;
+ viewPosition = (uView * vec4(rayOrigin + t * rayDir, 1.0)).xyz;
+ fragmentDepth = calcDepth(viewPosition);
+ if (fragmentDepth > 0.0) return true;
}
}
@@ -87,11 +94,33 @@ bool CylinderImpostor(
y = baoc + t * bard;
if (y > 0.0 && y < baba) {
interior = true;
- intersection = vec4(t, (oc + t * rayDir - ba * y / baba) / radius);
+ cameraNormal = -(oc + t * rayDir - ba * y / baba) / radius;
+ viewPosition = (uView * vec4(rayOrigin + t * rayDir, 1.0)).xyz;
+ fragmentDepth = calcDepth(viewPosition);
return true;
}
- // TODO: handle inside caps???
+ if (topCap && y < 0.0) {
+ // top cap
+ t = -baoc / bard;
+ if (abs(k1 + k2 * t) < -h) {
+ interior = true;
+ cameraNormal = ba / baba;
+ viewPosition = (uView * vec4(rayOrigin + t * rayDir, 1.0)).xyz;
+ fragmentDepth = calcDepth(viewPosition);
+ if (fragmentDepth > 0.0) return true;
+ }
+ } else if(bottomCap && y >= 0.0) {
+ // bottom cap
+ t = (baba - baoc) / bard;
+ if (abs(k1 + k2 * t) < -h) {
+ interior = true;
+ cameraNormal = -ba / baba;
+ viewPosition = (uView * vec4(rayOrigin + t * rayDir, 1.0)).xyz;
+ fragmentDepth = calcDepth(viewPosition);
+ if (fragmentDepth > 0.0) return true;
+ }
+ }
}
return false;
@@ -100,23 +129,21 @@ bool CylinderImpostor(
void main() {
#include clip_pixel
+ vec3 rayOrigin = vModelPosition;
vec3 rayDir = mix(normalize(vModelPosition - uCameraPosition), uCameraDir, uIsOrtho);
- vec4 intersection;
- bool interior;
- bool hit = CylinderImpostor(vModelPosition, rayDir, vStart, vEnd, vSize, intersection, interior);
+ vec3 cameraNormal;
+ vec3 viewPosition;
+ float fragmentDepth;
+ bool hit = CylinderImpostor(rayOrigin, rayDir, vStart, vEnd, vSize, cameraNormal, interior, viewPosition, fragmentDepth);
if (!hit) discard;
- vec3 vViewPosition = vModelPosition + intersection.x * rayDir;
- vViewPosition = (uView * vec4(vViewPosition, 1.0)).xyz;
- float fragmentDepth = calcDepth(vViewPosition);
-
if (fragmentDepth < 0.0) discard;
if (fragmentDepth > 1.0) discard;
gl_FragDepthEXT = fragmentDepth;
- vec3 vModelPosition = (uInvView * vec4(vViewPosition, 1.0)).xyz;
+ vec3 vModelPosition = (uInvView * vec4(viewPosition, 1.0)).xyz;
#include assign_material_color
#if defined(dRenderVariant_pick)
@@ -135,7 +162,7 @@ void main() {
gl_FragColor = material;
#elif defined(dRenderVariant_color)
mat3 normalMatrix = transpose3(inverse3(mat3(uView)));
- vec3 normal = normalize(normalMatrix * -normalize(intersection.yzw));
+ vec3 normal = normalize(normalMatrix * -normalize(cameraNormal));
#include apply_light_color
#include apply_interior_color
diff --git a/src/mol-gl/shader/cylinders.vert.ts b/src/mol-gl/shader/cylinders.vert.ts
index b6ea8d5b8..52c36b1e0 100644
--- a/src/mol-gl/shader/cylinders.vert.ts
+++ b/src/mol-gl/shader/cylinders.vert.ts
@@ -1,5 +1,5 @@
/**
- * Copyright (c) 2020 mol* contributors, licensed under MIT, See LICENSE file for more info.
+ * Copyright (c) 2020-2022 mol* contributors, licensed under MIT, See LICENSE file for more info.
*
* @author Alexander Rose <alexander.rose@weirdbyte.de>
*/
@@ -69,6 +69,9 @@ void main() {
vViewPosition = mvPosition.xyz;
gl_Position = uProjection * mvPosition;
+ mvPosition.z -= 2.0 * (length(vEnd - vStart) + vSize); // avoid clipping
+ gl_Position.z = (uProjection * mvPosition).z;
+
#include clip_instance
}
`;
\ No newline at end of file
diff --git a/src/mol-gl/shader/spheres.frag.ts b/src/mol-gl/shader/spheres.frag.ts
index 9b3def951..f02fc18f9 100644
--- a/src/mol-gl/shader/spheres.frag.ts
+++ b/src/mol-gl/shader/spheres.frag.ts
@@ -23,12 +23,8 @@ varying float vRadiusSq;
varying vec3 vPoint;
varying vec3 vPointViewPosition;
-vec3 cameraPos;
-vec3 cameraNormal;
-
-bool Impostor(out vec3 cameraPos, out vec3 cameraNormal){
+bool SphereImpostor(out vec3 cameraPos, out vec3 cameraNormal, out bool interior, out float fragmentDepth){
vec3 cameraSpherePos = -vPointViewPosition;
- cameraSpherePos.z += vRadius;
vec3 rayOrigin = mix(vec3(0.0, 0.0, 0.0), vPoint, uIsOrtho);
vec3 rayDirection = mix(normalize(vPoint), vec3(0.0, 0.0, 1.0), uIsOrtho);
@@ -37,49 +33,49 @@ bool Impostor(out vec3 cameraPos, out vec3 cameraNormal){
float B = dot(rayDirection, cameraSphereDir);
float det = B * B + vRadiusSq - dot(cameraSphereDir, cameraSphereDir);
- if (det < 0.0){
- discard;
- return false;
- }
+ if (det < 0.0) return false;
float sqrtDet = sqrt(det);
- float posT = mix(B + sqrtDet, B + sqrtDet, uIsOrtho);
- float negT = mix(B - sqrtDet, sqrtDet - B, uIsOrtho);
+ float posT = mix(B + sqrtDet, B - sqrtDet, uIsOrtho);
+ float negT = mix(B - sqrtDet, B + sqrtDet, uIsOrtho);
cameraPos = rayDirection * negT + rayOrigin;
+ fragmentDepth = calcDepth(cameraPos);
- if (calcDepth(cameraPos) <= 0.0) {
+ if (fragmentDepth > 0.0) {
+ cameraNormal = normalize(cameraPos - cameraSpherePos);
+ interior = false;
+ return true;
+ } else if (uDoubleSided) {
cameraPos = rayDirection * posT + rayOrigin;
+ fragmentDepth = calcDepth(cameraPos);
+ cameraNormal = -normalize(cameraPos - cameraSpherePos);
interior = true;
- } else {
- interior = false;
+ return true;
}
- cameraNormal = normalize(cameraPos - cameraSpherePos);
- cameraNormal *= float(!interior) * 2.0 - 1.0;
-
- return !interior;
+ return false;
}
void main(void){
#include clip_pixel
- bool flag = Impostor(cameraPos, cameraNormal);
- if (!uDoubleSided) {
- if (interior) discard;
- }
-
- vec3 vViewPosition = cameraPos;
- float fragmentDepth = calcDepth(vViewPosition);
- if (!flag && fragmentDepth >= 0.0) {
- fragmentDepth = 0.0 + (0.0000001 / vRadius);
- }
+ vec3 cameraPos;
+ vec3 cameraNormal;
+ float fragmentDepth;
+ bool hit = SphereImpostor(cameraPos, cameraNormal, interior, fragmentDepth);
+ if (!hit) discard;
if (fragmentDepth < 0.0) discard;
if (fragmentDepth > 1.0) discard;
+ if (interior && fragmentDepth >= 0.0) {
+ fragmentDepth = 0.0 + (0.0000001 / vRadius);
+ }
+
gl_FragDepthEXT = fragmentDepth;
+ vec3 vViewPosition = cameraPos;
vec3 vModelPosition = (uInvView * vec4(vViewPosition, 1.0)).xyz;
#include assign_material_color
diff --git a/src/mol-gl/shader/spheres.vert.ts b/src/mol-gl/shader/spheres.vert.ts
index 891a04f74..70a3daf72 100644
--- a/src/mol-gl/shader/spheres.vert.ts
+++ b/src/mol-gl/shader/spheres.vert.ts
@@ -1,5 +1,5 @@
/**
- * Copyright (c) 2019-2020 mol* contributors, licensed under MIT, See LICENSE file for more info.
+ * Copyright (c) 2019-2022 mol* contributors, licensed under MIT, See LICENSE file for more info.
*
* @author Alexander Rose <alexander.rose@weirdbyte.de>
*/
@@ -85,7 +85,6 @@ void main(void){
vec4 position4 = vec4(aPosition, 1.0);
vec4 mvPosition = uModelView * aTransform * position4;
- mvPosition.z -= vRadius; // avoid clipping, added again in fragment shader
gl_Position = uProjection * vec4(mvPosition.xyz, 1.0);
quadraticProjection(size, aPosition);
@@ -97,6 +96,9 @@ void main(void){
vModelPosition = (uModel * aTransform * position4).xyz; // for clipping in frag shader
+ mvPosition.z -= 2.0 * vRadius; // avoid clipping
+ gl_Position.z = (uProjection * vec4(mvPosition.xyz, 1.0)).z;
+
#include clip_instance
}
`;
\ No newline at end of file
--
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