RaVE

multithreaded simd Raytracer for Voxel Engines

Overview

C99 sse4 + pthreads CPU grid-aligned voxel raytracer created for internal needs of Lum engine

screenshots

Integration

#define every RAVE_* define you need before any of raytracer.* files included

• Include raytracer.h wherever you need
• Compile raytracer.c (if using any defines, make sure they are defined)
• Link with compiled object file

You may also just compile one of your objects files with raytracer.c included, just make sure that you link with only one implementation

• #Defines

  to use custom voxel type instead of uint8_t use

  #define RAVE_CUSTOM_VOXEL_TYPE custom_voxel_type //uint8_t is defualt
  #include "raytracer.h"

  to disable SIMD use

  #define RAVE_NO_SIMD
  #include "raytracer.h"

Integration

you need to implement all of the following functions in your code to make RaVE be able to interact with your voxel engine:

rave_voxel rave_get_voxel(int x, int y, int z);
rave_vec3  rave_get_ray_pos(int local_x, int local_y, int local_z);
rave_vec3  rave_get_ray_dir(int local_x, int local_y, int local_z);
void       rave_store_light(int local_x, int local_y, int local_z, rave_vec3 light);
Material   rave_get_material(rave_voxel voxel);

Also, create and set following variables

uint32_t max_steps; //steps taken before no-hit return
uint32_t max_reflections; //typically 7 is enough
rave_voxel rave_empty_voxel; //typically you would want it to be 0

rave_get_voxel(x,y,z) should return voxel in (x,y,z) position in voxel world space.

rave_get_material(voxel) should return voxel's material

Material represents simple reflectance distribution function, with 3-float color, float emmitance and float roughness parameters

use rave_dispatch(int count_x, int count_y, int count_z) to do calculations. This will trace count_x * count_y * count_z rays. Every ray will get its origin via rave_get_ray_pos(x,y,z), direction via rave_get_ray_dir(x,y,z) and will store raytraced light via rave_store_light(x,y,z)

typically you will only need one or two dimensions for dispatch, but third one can be used for multisampling

Examples

see tests/test.c (Cornell box) and tests/fractal.c (weirdly-colored voxelized Julia set) You can build them with Make (make test / make fractal)

License

MIT