RasterizeGaussians¶
Given 2D gaussians that are parametrized by their means \(μ'\) and covariances \(Σ'\) as well as their radii and conic parameters,
the gsplat.rasterize_gaussians()
function first sorts each gaussian such that all gaussians within the bounds of a tile are grouped and sorted by increasing depth \(z\),
and then renders each pixel within a tile with alpha-compositing.
The discrete rendering equation is given by:
Where
And
\(σ ∈ R^{2}\) is the Mahalanobis distance (here referred to as sigma) which measures how many standard deviations away the center of a gaussian and the rendered pixel center is which is denoted by delta \(∆.\)
The python bindings support conventional 3-channel RGB rasterization as well as N-dimensional rasterization with gsplat.rasterize_gaussians()
.
- gsplat.rasterize_gaussians(xys, depths, radii, conics, num_tiles_hit, colors, opacity, img_height, img_width, block_width, background=None, return_alpha=False)¶
Rasterizes 2D gaussians by sorting and binning gaussian intersections for each tile and returns an N-dimensional output using alpha-compositing.
Note
This function is differentiable w.r.t the xys, conics, colors, and opacity inputs.
- Parameters:
xys (Tensor) – xy coords of 2D gaussians.
depths (Tensor) – depths of 2D gaussians.
radii (Tensor) – radii of 2D gaussians
conics (Tensor) – conics (inverse of covariance) of 2D gaussians in upper triangular format
num_tiles_hit (Tensor) – number of tiles hit per gaussian
colors (Tensor) – N-dimensional features associated with the gaussians.
opacity (Tensor) – opacity associated with the gaussians.
img_height (int) – height of the rendered image.
img_width (int) – width of the rendered image.
block_width (int) – MUST match whatever block width was used in the project_gaussians call. integer number of pixels between 2 and 16 inclusive
background (Tensor) – background color
return_alpha (bool) – whether to return alpha channel
- Returns:
out_img (Tensor): N-dimensional rendered output image.
out_alpha (Optional[Tensor]): Alpha channel of the rendered output image.
- Return type:
A Tensor