Approximate Image-Space Interactive Refractions

Implementation of the paper An Approximate Image-Space Approach for Interactive Refraction which proposes a technique for rendering refractions through two interfaces.

Build Instructions

As this project uses CMake, simply use your favourite CLI/IDE/code editor and compile the RefractionsExec target. A compiler supporting C++20 or higher is required. All dependencies are included in this repository and compiled as needed. The textures and models utilised can be downloaded here (Google Drive link).

Implementation Details

• Unlike the original paper, 3 passes are used in total. This allows front-face and back-face data to be rendered to textures for viewing
  • The first pass outputs depth, normal, and inner object distance data for front-faces
  • The second pass outputs depth, normal, and inner object distance data for back-faces
  • The third pass combines data from the previous two passes to render the final refractions. Geometry data from the rendered model is not used in this pass; it is only used to produce the relevant fragments
• A screen quad is used to render each of the 6 previous textures when desired
• A software ray-tracer is used to compute the inner object distances ($d_{\overrightarrow{N}}$ in the paper) on a per-vertex basis when a model is first loaded. A version of the mesh with these values is saved to a cache file to accelerate subsequent loads of the same model
• Additionally, the color of the medium can be changed. This attenuates the refracted light twice, once for each interface

Libraries Used

• GLAD
• GLFW3
• GLM
• ImGui
• Native File Dialog
• stb
• tinyobjloader
• cereal