Gaussian Splatting

Gaussian splatting is a cutting-edge technique in computer graphics for rendering 3D scenes. It represents scenes using a collection of Gaussian functions that describe points in space with attributes such as position, color, and transparency. This approach allows for the creation of detailed and realistic images by directly rendering volume data, resulting in smoother and more natural visuals compared to traditional methods that rely on polygons or voxels. Gaussian splatting is particularly beneficial for applications requiring high-quality rendering, such as virtual reality and scientific visualization. 

Advantages over Traditional Photogrammetry: 

Handling Complex Surfaces and Materials: Gaussian splatting excels in accurately representing reflective or transparent objects, as well as thin or intricate structures like wires and cables, where traditional photogrammetry may struggle. 

Gaussian Splatting (Left) VS Reality Mesh (Right): a typical communication tower use case where the Gaussian splatting rendering surpasses the Reality Mesh

Drawbacks over traditional photogrammetry:

Gaussian Splatting is more sensible to viewing angle and requires the scene to be captured from every angle to allow for seamless visualization. It makes it very effective for scenes like communication towers where most of the viewing angles are covered through orbiting around the structure. However, the mesh result will be much better for Nadir datasets, as soon as the viewing angle is too far from an angle covered by a photos in the dataset. 

Gaussian Splatting (Left) VS Reality Mesh (Right): a typical Nadir user case where the Gaussian splatting rendering is not providing good results compared to the Reality Mesh

To ensure optimal performance when using Gaussian splatting in iTwin Capture Modeler, your system should meet the following minimum requirements: 

• CPU: Intel Core i7 / AMD Ryzen 9  

• GPU: NVidia RTX Series with 8GB VRAM  

Any NVIDIA RTX series (RTX 20 or higher for GeForce, RTX x000 or higher for Quadro). Note: GPUs like the GTX 1080 are not supported. 

• RAM: 32 GB  

• OS: Windows 11 (64Bit) 

• Storage: 8 GB Available Space for Installer 

A NVMe SSD is recommended for Installer & Quick Processing 

To manage performance and memory usage, the algorithm automatically limits the number of splats per tile.

• Why tiles matter:
  Each tile has a maximum number of splats that can be processed, based on:
  • Image resolution
  • Chosen quality
  • Available GPU memory (VRAM)
• Impact on quality:
  If the tile size is too large, the algorithm may not allocate enough splats per tile, resulting in less detail or precision.
  If you need higher accuracy, you should reduce the tile size, which increases the number of tiles and allows more splats overall.
• Important note:
  It is difficult to predict the optimal tile size in advance because it depends on your hardware and scene complexity. Start with the default setting, and if the output looks imprecise, try smaller tiles for better quality (at the cost of longer processing time).