Node reference

Nodes are grouped as in the add-node menu. Runs says when a node does its work; Implemented by names the Klartraum class or function behind it.

Sources

Node	Description	Implemented by	Runs
Scene	Loads a 3D Gaussian model from an .spz file into CPU memory, optionally mirrored across Y for Nerfstudio exports.	klartraum::loadGaussiansSpz	once, when the graph is built
Image File	Loads an image file (PNG, JPEG, …), resized to W×H, as a 1×3×H×W tensor with values in [0, 1].	klartraum::TensorElement	once, when the graph is built

Numbers (CPU)

Node	Description	Implemented by	Runs
Number	A constant number.	studio	every frame (live), once per run
Time	Seconds since the studio started, times a speed.	studio	every frame (live), once per run
Sine	amplitude · sin(frequency · 2π · x + phase) + offset, e.g. to swing something back and forth.	studio	every frame (live), once per run
Upload Number	Copies a CPU number into a GPU buffer before every frame, without rebuilding the graph.	klartraum::HostFloat	every frame (live), once per run

Gaussians (CPU)

Node	Description	Implemented by	Runs
Transform (CPU)	Scales, rotates and moves Gaussians in CPU memory; orientations and view-dependent colour turn along.	klartraum::transformGaussians	once, when the graph is built
Merge (CPU)	Combines two sets of Gaussians in CPU memory into one, rendered and sorted together.	studio	once, when the graph is built
Upload Gaussians	Uploads Gaussians into the GPU buffers a Gaussian Splatting reads.	klartraum::GaussianDataStandard	once, when the graph is built

Gaussians (GPU)

Node	Description	Implemented by	Runs
Make Transform	A GPU transform from translation, rotation (degrees about X, then Y, then Z) and scale. Inputs that are not connected take the node’s values, which apply without rebuilding.	klartraum::TransformBuffer	every frame (live) or every run
Transform (GPU)	Moves Gaussians on the GPU by a transform, every frame.	klartraum::GaussianTransform	every frame (live) or every run
Merge (GPU)	Combines two sets of Gaussians on the GPU, every frame.	klartraum::GaussianMerge	every frame (live) or every run

Rendering

Node	Description	Implemented by	Runs
Orbit Camera	Camera uniform buffer driven by an orbit camera.	klartraum::InterfaceCameraOrbit	every frame (live), once per run
Swapchain Target	The window’s swapchain images, rendered into directly.	klartraum::ImageViewSrc	every frame (live only)
Offscreen Target	An image of fixed size (W×H) to render into for further processing.	klartraum::OffscreenTarget	every frame (live) or every run
Gaussian Splatting	Renders the Gaussians into the target image, with the compute or raster backend and all klartraum::GsplatConfig settings.	klartraum::createGaussianSplatting	every frame (live) or every run

Compute

Node	Description	Implemented by	Runs
Image to Tensor	Converts a rendered image into a 1×3×H×W tensor.	klartraum::GeneralComputation	every frame (live) or every run
Tensor to Image	Converts a 1×3×H×W tensor (values in [0, 1]) into an H×W image.	klartraum::GeneralComputation	every frame (live) or every run
Resample	Resamples an image to W×H, nearest or bilinear.	klartraum::ImageResample	every frame (live) or every run
ONNX Model	Runs an ONNX network on a tensor (Conv, ConvTranspose, Relu, Reshape, Transpose).	klartraum::OnnxNetwork	every frame (live) or every run

Outputs

Node	Description	Implemented by	Runs
Present	Shows the image in the window every frame, stretched to the window’s size.	klartraum::ImageResample, added by the studio	every frame (live only)
Preview	Shows a 1- or 3-channel image tensor, or an image, when the graph is run.	studio (read back, shown as an ImGui texture)	every run
Image File Writer	Writes a 1- or 3-channel image tensor, or an image, to a PNG file when the graph is run.	studio (read back, written with stb_image_write)	every run