Commit blob of documentation

README.md

@@ -0,0 +1,11 @@
+# jtracer
+
+**jtracer** is a C++ raytracer capable of running either on the CPU (multithreaded or non-multithreaded) or as an Apple Metal compute kernel.
+
+The raytracer was originally based on the implementation guide given by Peter Shirley's excellent ebook [Ray Tracing In One Weekend](https://www.amazon.com/Ray-Tracing-Weekend-Minibooks-Book-ebook/). The algorithms were modified to make the raytracer non-allocating (i.e. non stack based) by using color/light accumulators with a single ray object to trace through the scene.
+
+The implementation found in [`jtracer/Trace`](jtracer/Trace) is designed to be extremely portable. It is a header-only implementation of a general GPU-compute compatible raytracer from a per-pixel standpoint given a set of scene parameters (in this case, a bunch of spheres). In theory, it should work in an OpenCL C++ or CUDA environment with little modification - likely just some system-specific definitions in [`JTTypes.h`](jtracer/Trace/JTTypes.h).
+
+The frontend is written in Objective-C++. It is tested with Xcode 9.3 under macOS 10.13.4. The UI is extremely simple - all options are hardcoded within the app. On startup the main window will display two views: the top is a GPU-compute render via Metal, and the bottom is a multicore CPU render scheduled by `libdispatch` (Grand Central Dispatch). Below is a screenshot:
+
+<img src="https://github.com/jonathonracz/jtracer/blob/master/screenshot.png?raw=true" alt="Screenshot, as described above.">

jtracer.xcodeproj/project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEDidComputeMac32BitWarning</key>
+	<true/>
+</dict>
+</plist>

jtracer/JTRenderState.mm

@@ -29,6 +29,7 @@ - (id)init {
         _uniformsInternal->spheres[0].materialParams.albedo = make_float3(1.0f, 0.0f, 0.0f);
         _uniformsInternal->spheres[0].materialParams.roughness = 0.0f;
         _uniformsInternal->spheres[0].materialParams.reflectivity = 1.0f;
+        _uniformsInternal->spheres[0].materialParams.transparency = 1.0f;
 
         _uniformsInternal->spheres[1].materialParams.albedo = make_float3(0.0f, 1.0f, 0.0f);
         _uniformsInternal->spheres[1].materialParams.roughness = 0.25f;

jtracer/JTRenderViewController.mm

@@ -40,7 +40,7 @@ - (void)viewDidLoad {
 
 - (void)renderViews:(JTDisplayLink *)sender {
     [_renderState update:_displayLink.timestamp];
-    //[self.metalRenderer render:_renderState sender:_displayLink];
+    [self.metalRenderer render:_renderState sender:_displayLink];
     [self.cgRenderer render:_renderState sender:_displayLink];
 }
 

jtracer/Trace/JTBSDF.h

@@ -32,16 +32,23 @@ inline float3 scatter(JT_THREAD PRNG& random, JT_THREAD const Parameters& params
 
     float3 scattered = make_float3(0.0f, 0.0f, 0.0f);
 
-    float3 reflection = Math::reflect(incident, normal);
-    float3 diffuse = random.generateInUnitSphere();
-    // Make sure the diffuse ray is actually a reflection - i.e. leaving the
-    // object.
-    if (dot(diffuse, normal) < 0)
-        diffuse *= -1.0f;
-
-    // TODO: This may be better off as a slerp so there isn't a lopsided
-    // resolution between the center and edges of the interpolation...
-    scattered = Math::lerp(reflection, diffuse, params.roughness);
+    //if (isReflection)
+    {
+        float3 reflection = Math::reflect(incident, normal);
+        float3 diffuse = random.generateInUnitSphere();
+        // Make sure the diffuse ray is actually a reflection - i.e. leaving the
+        // object.
+        if (dot(diffuse, normal) < 0)
+            diffuse *= -1.0f;
+
+        // TODO: This may be better off as a slerp so there isn't a lopsided
+        // resolution between the center and edges of the interpolation...
+        scattered = Math::lerp(reflection, diffuse, params.roughness);
+    }
+    //else
+    {
+        // Refraction
+    }
 
     assert(!equal(scattered, make_float3(0.0f, 0.0f, 0.0f)));
 

jtracer/Trace/JTPath.h

@@ -23,7 +23,7 @@ class Path
     {
     }
 
-    float3 trace(JT_THREAD Ray ray)
+    float3 trace(Ray ray)
     {
         Sphere::HitRecord hitRecord;