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FauxGL

3D software rendering in pure Go. No OpenGL, no C extensions, no nothin'.


Dragon

About

It's like OpenGL, but it's not. It's FauxGL.

It doesn't use your graphics card, only your CPU. So it's slow and unsuitable for realtime rendering. But it's still pretty fast. It works the same way OpenGL works - rasterizing.

Features

  • STL, OBJ, PLY, 3DS file formats
  • triangle rasterization
  • vertex and fragment "shaders"
  • view volume clipping
  • face culling
  • alpha blending
  • textures
  • triangle & line meshes
  • depth biasing
  • wireframe rendering
  • built-in shapes (plane, sphere, cube, cylinder, cone)
  • anti-aliasing (via supersampling)
  • voxel rendering
  • parallel processing

Performance

FauxGL uses all of your CPU cores. But none of your GPU.

Rendering the Stanford Dragon shown above (871306 triangles) at 1920x1080px takes about 150 milliseconds on my machine. With 4x4=16x supersampling, it takes about 950 milliseconds. This is the time to render a frame and does not include loading the mesh from disk.

Go Get

go get -u github.com/fogleman/fauxgl

Go Run

cd go/src/github.com/fogleman/fauxgl
go run examples/hello.go

Go Doc

https://godoc.org/github.com/fogleman/fauxgl

Complete Example

package main

import (
	. "github.com/fogleman/fauxgl"
	"github.com/nfnt/resize"
)

const (
	scale  = 1    // optional supersampling
	width  = 1920 // output width in pixels
	height = 1080 // output height in pixels
	fovy   = 30   // vertical field of view in degrees
	near   = 1    // near clipping plane
	far    = 10   // far clipping plane
)

var (
	eye    = V(-3, 1, -0.75)               // camera position
	center = V(0, -0.07, 0)                // view center position
	up     = V(0, 1, 0)                    // up vector
	light  = V(-0.75, 1, 0.25).Normalize() // light direction
	color  = HexColor("#468966")           // object color
)

func main() {
	// load a mesh
	mesh, err := LoadOBJ("examples/dragon.obj")
	if err != nil {
		panic(err)
	}

	// fit mesh in a bi-unit cube centered at the origin
	mesh.BiUnitCube()

	// smooth the normals
	mesh.SmoothNormalsThreshold(Radians(30))

	// create a rendering context
	context := NewContext(width*scale, height*scale)
	context.ClearColorBufferWith(HexColor("#FFF8E3"))

	// create transformation matrix and light direction
	aspect := float64(width) / float64(height)
	matrix := LookAt(eye, center, up).Perspective(fovy, aspect, near, far)

	// use builtin phong shader
	shader := NewPhongShader(matrix, light, eye)
	shader.ObjectColor = color
	context.Shader = shader

	// render
	context.DrawMesh(mesh)

	// downsample image for antialiasing
	image := context.Image()
	image = resize.Resize(width, height, image, resize.Bilinear)

	// save image
	SavePNG("out.png", image)
}

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