From 739e1dfe7e406ca3ef18a9aa92fa34bc3506d114 Mon Sep 17 00:00:00 2001
From: Lucas Crane <cabot696@gmail.com>
Date: Tue, 14 Jan 2020 13:37:55 -0500
Subject: [PATCH] Tweak reprojection amount & decrease bounces to 2 (#58)

* tweak reprojection amount

* lower numUniformSamples and maxReprojectedSamples

* increase numUniformSamples from 3 to 4 for scenes with more GI

Co-authored-by: Noah Lyons <n.lyons53@gmail.com>
---
 scenes/webgl-comparison/main.js   | 1 +
 src/RayTracingRenderer.js         | 2 +-
 src/renderer/RenderingPipeline.js | 7 +++----
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/scenes/webgl-comparison/main.js b/scenes/webgl-comparison/main.js
index 5b810ee..9e94710 100644
--- a/scenes/webgl-comparison/main.js
+++ b/scenes/webgl-comparison/main.js
@@ -154,6 +154,7 @@ function initRenderer(renderer) {
   renderer.toneMapping = THREE.ACESFilmicToneMapping;
   renderer.toneMappingExposure = 1.5;
   renderer.renderWhenOffFocus = false;
+  renderer.bounces = 3;
 }
 
 function unloadRenderer(renderer) {
diff --git a/src/RayTracingRenderer.js b/src/RayTracingRenderer.js
index 626e98a..24fa396 100644
--- a/src/RayTracingRenderer.js
+++ b/src/RayTracingRenderer.js
@@ -31,7 +31,7 @@ export function RayTracingRenderer(params = {}) {
   let pixelRatio = 1;
 
   const module = {
-    bounces: 3,
+    bounces: 2,
     domElement: canvas,
     maxHardwareUsage: false,
     needsUpdate: true,
diff --git a/src/renderer/RenderingPipeline.js b/src/renderer/RenderingPipeline.js
index 572fddd..1b8ba35 100644
--- a/src/renderer/RenderingPipeline.js
+++ b/src/renderer/RenderingPipeline.js
@@ -18,11 +18,10 @@ export function makeRenderingPipeline({
     bounces, // number of global illumination bounces
   }) {
 
-  const reprojectDecay = 0.975;
-  const maxReprojectedSamples = Math.round(reprojectDecay / (1 - reprojectDecay));
+  const maxReprojectedSamples = 20;
 
   // how many samples to render with uniform noise before switching to stratified noise
-  const numUniformSamples = 6;
+  const numUniformSamples = 4;
 
   // how many partitions of stratified noise should be created
   // higher number results in faster convergence over time, but with lower quality initial samples
@@ -231,7 +230,7 @@ export function makeRenderingPipeline({
     reprojectBuffer.bind();
     gl.viewport(0, 0, previewWidth, previewHeight);
     reprojectPass.draw({
-      blendAmount: reprojectDecay,
+      blendAmount: 1.0,
       light: hdrBuffer.attachments[rayTracePass.outputLocs.light],
       position: hdrBuffer.attachments[rayTracePass.outputLocs.position],
       textureScale: previewScale,