message: mini example currently doesn't work
diff: @@ -74,66 +74,6 @@ The headers, libraries and viewer will then be located in the standard install p
  See the [Getting Started Guide](https://github.com/szellmann/visionaray/wiki/Getting-started) and the [Troubleshooting section](https://github.com/szellmann/visionaray/wiki/Troubleshooting) in the [Wiki](https://github.com/szellmann/visionaray/wiki) for further information.
  -Mini Example
  -------------
  -
  -The following example illustrates how easy it is to write a simple ray tracing program with Visionaray.
  -
  -```cpp
  -#include <random>
  -#include <vector>
  -#include <visionaray/math/math.h>
  -#include <visionaray/bvh.h>
  -#include <visionaray/pinhole_camera.h>
  -#include <visionaray/scheduler.h>
  -#include <visionaray/simple_buffer_rt.h>
  -#include <visionaray/traverse.h>
  -#define STB_IMAGE_WRITE_IMPLEMENTATION 1
  -#include "stb/stb_image_write.h"
  -
  -using namespace visionaray;
  -
  -int main() {
  - aabb bbox{{-1.f,-1.f,-1.f},{1.f,1.f,1.f}};
  - pinhole_camera cam;
  - cam.set_viewport(0,0,1024,1024);
  - cam.perspective(45.f*constants::pi<float>()/180.f,1.f,.001f,1000.f);
  - cam.view_all(bbox);
  -
  - simple_buffer_rt<PF_RGBA8, PF_UNSPECIFIED> renderTarget;
  - renderTarget.resize(1024,1024);
  -
  - int numThreads=8;
  - tiled_sched<ray> sched(numThreads);
  - auto sparams = make_sched_params(cam,renderTarget);
  -
  - std::default_random_engine rand;
  - std::uniform_real_distribution<float> c(-1.f,1.f);
  - std::uniform_real_distribution<float> r(.001f,.05f);
  - std::vector<basic_sphere<float>> spheres(500);
  - for (int i=0; i<500; ++i) {
  - spheres[i].prim_id = i;
  - spheres[i].center = vec3(c(rand),c(rand),c(rand));
  - spheres[i].radius = r(rand);
  - }
  -
  - lbvh_builder builder;
  - auto bvh = builder.build(index_bvh<basic_sphere<float>>{},spheres.data(),
  - spheres.size());
  - auto ref = bvh.ref();
  -
  - sched.frame([=](ray r) -> vec4 {
  - auto hr = closest_hit(r,&ref,&ref+1);
  - if (hr.hit) return vec4(vec3(1.f,.9f,.4f)*spheres[hr.prim_id].radius*20.f,1.f);
  - else return vec4(0.f,0.f,0.f,1.f);
  - }, sparams);
  -
  - stbi_write_png("result.png",1024,1024,4,renderTarget.color(),1024*sizeof(uint32_t));
  -}
  -```
  -
  -Just build the program by putting it in a file called `mini.cpp` and compile it as follows (this assumes that you have the STB headers in your include path (https://github.com/nothings/stb):
  -
  ```Shell
  c++ mini.cpp -std=c++14 -I/path/to/visionaray/include -o mini
  ```
  