Ecosystems:
Go
GoTracer
- Software Raytracer written in golang.
- Images can be previewed directly on the window as they are rendered.
- Interaction can be done using keys from the keyboard, to control the camera.
Screenshots
Performance
- To improve performance multi-threading was added to the renderer.
- Data had to be reordered for go to actually scale properly with multiple threads.
- Calling multiple goroutines that use that same data cause them to lock on each other to access data and the performance gains are minimal.
- Tests were performed with 154 objects in the render scene.
- Tests performed on a Core i5 6500 (4 Core) with DDR3 memory w/ 4 threads.
- Tested base performance number for a single thread.
- Tested splitting the work by multiple goroutines each routine processes one portion of the output.
- Tested explicit object copies for each thread was able to reduce time further by skipping the synchronization points added by the go race condition detector.
| Mode | Resolution | Time p/ frame | Speedup |
|---|---|---|---|
| Single-thread | 320x240 | ~430ms | 1x |
| Single-thread | 640x480 | ~1750ms | 1x |
| GoRoutine | 320x240 | ~220ms | 1.95x |
| GoRoutine | 640x480 | ~650ms | 2.69x |
| Explicit Data Copy | 320x240 | ~120ms | 3.58x |
| Explicit Data Copy | 640x480 | ~620ms | 3.64x |
| go:norace | 320x240 | ~160ms | 2.54x |
| go:norace | 640x480 | ~650ms | 2.69x |
- Performed new tests on new Go 1.12.8, also tested the go:norace flag, will have to repeat on a CPU with more cores.
- Using the //go:norace code annotation to skip the data race condition analysis.
- Test platform was a Core i7 3537u (2 Core HT) running Go 1.12.8 w/ 4 threads, in the CPU it was easy to double the performance without the implicit sync points being a problem.
| Mode | Resolution | Time p/ frame |
|---|---|---|
| Single-thread | 320x240 | ~590ms |
| Single-thread | 640x480 | ~2250ms |
| GoRoutine | 320x240 | ~295ms |
| GoRoutine | 640x480 | ~1100ms |
| Explicit Data Copy | 320x240 | ~280ms |
| Explicit Data Copy | 640x480 | ~1200ms |
| go:norace | 320x240 | ~285ms |
| go:norace | 640x480 | ~1090ms |
Features
- Geometries (Sphere, Box, Triangles).
- Materials (Dieletrics, Lambert, Metal, Normal).
- Camera defocus.
- Filtering
- Antialiased image from ray jittering.
- Temporal accomulation from single ray raytraced images.
- File loaders (.obj)
Build
- Install golang development tools
- If youre running on Windows install the GCC compiler
- http://win-builds.org/doku.php.
- Add the winbuils/bin folder to the path.
- Alternatively you can use MSYS2
- Run go get and go build.
- Run the executable
Libraries
- PixelGL
- Used to create windows, output image and get key inputs
- https://godoc.org/github.com/gopxl/pixel/pixelgl
- https://github.com/gopxl/pixel/wiki/Creating-a-Window
- https://godoc.org/github.com/gopxl/pixel/#PictureData
References
- Raytracer in a Weekend (Peter Shirley)
- An efficient and robust ray-box intersection algorithm (2003) (Amy Williams , Steve Barrus , R. Keith , Morley Peter Shirley)
Package Rankings
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