A Method Calculates Transparency in 3D Gaussian Splatting
The 3D Gaussian Splatting (3DGS) technique has revolutionized how radiance fields are optimized and visualized in real time. However, its simplified approach to blending colors and calculating density has a major drawback: it cannot effectively represent semitransparent objects that overlap in complex ways. 🎯
Closing the Gap Between Rasterization and Real Physics
To overcome this barrier, an extension of rasterization-based rendering has been proposed. Its goal is to calculate transmittance with high fidelity, completely dispensing with costly techniques like ray tracing or sorting samples per pixel. This brings the speed of rasterization closer to the precision of more complex physical methods.
The Fundamentals of the New Approach:- It is based on previous research on order-independent transparency of samples.
- The central idea is to describe the density distribution along each camera ray in a compact way.
- To achieve this, a continuous representation based on statistical moments is used.
Now transparent objects in 3DGS no longer look like dirty glass seen through another dirty glass.
Processing Moments to Reconstruct Transmittance
The method analytically derives and processes a set of moments per pixel. These moments are generated from all the 3D Gaussians that contribute to that pixel. With this information, the system is able to reconstruct a continuous transmittance function for each individual ray, which is key to modeling light attenuation.
Implementing the Reconstruction:- The reconstructed transmittance function is sampled independently within each 3D Gaussian.
- This step is crucial for accurately modeling how light attenuates when passing through translucent media with complex structures.
- The process closes the existing technical gap, substantially improving the final quality in both reconstruction and visualization.
Result: A Leap in Realism and Quality
The main advantage of this method is that it overcomes the limitations of the simplified alpha blending used by 3DGS by default. Semitransparent objects stop being perceived as flat and disordered layers, and instead show the physical complexity they should have. This represents a significant advance in making real-time rendering not only fast, but also visually accurate. ✨