This project implements a ray tracer using the awesome parallelization abilities of the GPU using CUDA. Ray tracing is by itself an embarrasingly parallel algorithm, each pixel can be processed independently of the other pixels.

• Parse a scene description format (TAKUAscene as described below)
• Support for multiple point lights
• Phong shading model

This project uses a custom scene description format, called TAKUAscene. TAKUAscene files are flat text files that describe all geometry, materials, lights, cameras, render settings, and animation frames inside of the scene. Items in the format are delimited by new lines, and comments can be added at the end of each line preceded with a double-slash.

Materials are defined in the following fashion:

• MATERIAL (material ID) //material header
• RGB (float r) (float g) (float b) //diffuse color
• SPECX (float specx) //specular exponent
• SPECRGB (float r) (float g) (float b) //specular color
• REFL (bool refl) //reflectivity flag, 0 for no, 1 for yes
• REFR (bool refr) //refractivity flag, 0 for no, 1 for yes
• REFRIOR (float ior) //index of refraction for Fresnel effects
• SCATTER (float scatter) //scatter flag, 0 for no, 1 for yes
• ABSCOEFF (float r) (float b) (float g) //absorption coefficient for scattering
• RSCTCOEFF (float rsctcoeff) //reduced scattering coefficient
• EMITTANCE (float emittance) //the emittance of the material. Anything >0 makes the material a light source.

Cameras are defined in the following fashion:

• CAMERA //camera header
• RES (float x) (float y) //resolution
• FOVY (float fovy) //vertical field of view half-angle. the horizonal angle is calculated from this and the reslution
• ITERATIONS (float interations) //how many iterations to refine the image, only relevant for supersampled antialiasing, depth of field, area lights, and other distributed raytracing applications
• FILE (string filename) //file to output render to upon completion
• frame (frame number) //start of a frame
• EYE (float x) (float y) (float z) //camera's position in worldspace
• VIEW (float x) (float y) (float z) //camera's view direction
• UP (float x) (float y) (float z) //camera's up vector

Objects are defined in the following fashion:

• OBJECT (object ID) //object header
• (cube OR sphere OR mesh) //type of object, can be either "cube", "sphere", or "mesh". Note that cubes and spheres are unit sized and centered at the origin.
• material (material ID) //material to assign this object
• frame (frame number) //start of a frame
• TRANS (float transx) (float transy) (float transz) //translation
• ROTAT (float rotationx) (float rotationy) (float rotationz) //rotation
• SCALE (float scalex) (float scaley) (float scalez) //scale

An example TAKUAscene file setting up two frames inside of a Cornell Box can be found in the scenes/ directory.

The following renders were done to check the correctness of the code and various routines

• Test the code that casts rays

• Test the intersection tests code

• Test diffuse falloffs ( dot product of light direction and normals)

• Test specular highlights

• Phong shading

• Supersampling and reflections