Add Gaussian Splatting support (.ply / .splat / .spz) by bobicloudvision · Pull Request #892 · BabylonJS/Editor

bobicloudvision · 2026-06-24T11:45:25Z

Summary

Adds end-to-end support for Gaussian Splatting assets (.ply, .splat, .spz) across the whole editor pipeline: import, viewport rendering, scene graph, inspector, save/load, and export to the runtime. Previously the editor had no concept of splats — they couldn't be imported, rendered, or persisted.

The data round-trip leans on Babylon's native GaussianSplattingMesh and the babylonjs-loaders SPLAT loader (engine 9.12.1): serialize() embeds the splat data inline and Mesh.Parse() dispatches back to the Gaussian parser. The bulk of the work here is wiring those into the editor's import/graph/save/export flows, plus a set of splat-specific correctness fixes uncovered during testing.

Changes Made

Import

Registered .ply / .splat / .spz as model assets; they can be dropped into the viewport or imported from the Assets Browser.
Import splats with keepInRam: true, otherwise the splat buffer is freed right after GPU upload and serialize() would persist an empty mesh.
Applied the editor's centimeters convention (×100, the same scaling glTF receives through its __root__) directly to the splat mesh, since splats have no __root__. The SPLAT loader's own orientation (scaling.y = -1) is preserved.

Scene graph & inspector

GaussianSplattingMesh is recognized as an abstract mesh, so it shows in the graph, is selectable, and gets the mesh inspector for transform editing.
The inspector hides sections that don't apply to splats (collision, physics, shadows, material) and skips the selection-outline pass.
Internal per-camera proxy meshes the renderer creates (<splat>_cameraMesh_<id>, flagged reservedDataStore.hidden) are excluded from the graph.

Rendering correctness

Splat meshes are kept out of shadow-map render lists and depth/outline passes — their thin-instance layout can't be drawn there and was producing glDrawElementsInstanced: vertex buffer not big enough. Splats persisted in a shadow render list by older projects are stripped on load.

Save & Load

The splat mesh is saved with its data inline; the unused serialized material and quad geometry are stripped so no useless .babylonbinarymeshdata is written.
On load, uniqueId/parent are restored while the standard material/geometry reconciliation is skipped.
Internal hidden meshes are never written to disk.

Export & Runtime

Export skips geometry externalization for splats and keeps internal hidden proxies out of the output.
The tools/ runtime imports the GaussianSplatting side-effect module so the .babylon loader can reconstruct splat meshes at runtime.

Benefits

Users can drag a .ply / .splat / .spz capture straight into a scene and see it rendered, positioned, and scaled consistently with the rest of their content.
Splats behave like first-class scene objects — visible in the graph, selectable, and transformable via the inspector, with no internal/proxy nodes cluttering the tree.
Scenes containing splats save, reopen, and export to the runtime reliably, with no shadow-pass rendering errors.
No engine upgrade or extra dependency required — built entirely on the Babylon version already in the project.

Adds full-pipeline support for Gaussian splatting assets across import, editor preview, save/load, export and runtime: - extensions: register .ply/.splat/.spz as model assets (SPLAT loader is already provided by babylonjs-loaders) - guards: add isGaussianSplattingMesh and recognize GaussianSplattingMesh as an abstract mesh so it shows in the graph, is selectable and gets the mesh inspector (transforms) - import: skip the glTF x100 centimeters scaling for splats (metric space) - preview/assets-browser: accept splat files on drop and in the browser - save: include GaussianSplattingMesh; the splat data is embedded inline by Babylon's native serialize(), so drop the unused serialized material and quad geometry to avoid writing a useless .babylonbinarymeshdata file - load: restore uniqueId/parent for splat meshes, skipping the regular material/geometry reconciliation - export: skip geometry externalization/delay-loading for splat meshes - tools runtime: import the GaussianSplatting side-effect module so the .babylon loader's Mesh.Parse can reconstruct splat meshes inline

…lized GaussianSplattingMesh frees its splat buffer right after uploading it to the GPU when keepInRam is false (the default). serialize() only writes splatsData when the buffer is still present, so saving/exporting a splat produced an empty mesh that failed to render on reload (glDrawElementsInstanced: vertex buffer not big enough). Pass `keepInRam: true` to the SPLAT loader on import so the data is retained and round-trips through save/load/export. The flag is serialized with the mesh, so reloaded and exported splats keep their data too. Ignored by non-splat loaders.

… passes - import: flip Y back on imported Gaussian splatting meshes so they appear upright. The SPLAT loader bakes a `scaling.y *= -1` to convert from the common Y-down splat convention, but plain .splat/.ply/.spz files carry no up-axis metadata and end up upside down in the editor's left-handed scene. - graph / configure / shadow-generators: never add Gaussian splatting meshes to shadow-map render lists (and strip them from lists persisted by older projects). Their thin-instance splat layout can't be drawn by the depth pass and triggered "glDrawElementsInstanced: vertex buffer not big enough". - mesh inspector: hide collision/physics/shadows/material sections for splats and skip the selection-outline pass (same depth-pass limitation). - layout: bump layout version to refresh persisted panel layout.

The SPLAT loader already orients the splat correctly (it bakes scaling.y = -1 to convert from the Y-down splat convention); the previous extra `scaling.y *= -1` flipped it upside down. Remove that flip. Also apply the editor's centimeters convention to splats: glTF gets a x100 scale via its __root__, but splat meshes have no root and were left at meter scale, appearing ~100x too small next to other content. Scale the splat mesh x100 on import.

…ave/export A GaussianSplattingMesh creates a per-camera proxy mesh at render time (name "<splat>_cameraMesh_<id>") flagged with reservedDataStore.hidden and doNotSerialize. These leaked into the editor scene graph and could be written as standalone meshes on save. - isNodeVisibleInGraph: treat reservedDataStore.hidden nodes as not visible, which excludes them from both the graph panel and the save filter. - export: keep reservedDataStore.hidden meshes flagged doNotSerialize so they are not emitted as standalone meshes.

julien-moreau · 2026-06-24T12:41:35Z

Thanks! Looks good but I have to try and maybe some doubts on some parts. I'm coming back soon

julien-moreau · 2026-06-24T12:46:28Z

@hefujie-msn

bobicloudvision · 2026-06-24T13:13:24Z

if there are any performance issues somewhere.. tell me and I'll fix them

julien-moreau

Hey I finally tried it here are some comments.
Also, like for geometries, try to not save the "splatData" into the JSON file directly but more into a binary one like for geometries.

julien-moreau · 2026-06-27T13:04:10Z

@@ -1,3 +1,7 @@
+// Registers the GaussianSplattingMesh parser (Mesh._GaussianSplattingMeshParser) so the .babylon scene
+// loader can reconstruct Gaussian splatting meshes serialized inline by the editor.
+import "@babylonjs/core/Meshes/GaussianSplatting/gaussianSplattingMesh";


This must be performed by the devloper in his project so all projects don't include gaussian splatting in their builds

julien-moreau · 2026-06-27T13:04:48Z

+	// Internal nodes flagged hidden through Babylon's reservedDataStore convention (e.g. the per-camera
+	// proxy meshes a GaussianSplattingMesh creates at render time) are implementation details and must
+	// never show in the graph nor be saved.
+	if (node.reservedDataStore?.hidden) {


Is reservedDataStore?.hidden used especially by splat meshes? I did not need this until now

julien-moreau · 2026-06-27T13:07:19Z

 				if (shadowMap) {
 					shadowMap.refreshRate = data.refreshRate ?? RenderTargetTexture.REFRESHRATE_RENDER_ONEVERYFRAME;
+
+					// Gaussian splatting meshes can't be rendered into shadow maps (their thin-instance splat


I found this example that uses splats as shadow casters: https://playground.babylonjs.com/?inspectorv2=true#OE54M5#15. Can you double-check?

julien-moreau · 2026-06-27T13:15:46Z

 				case ".babylon":
+				case ".ply":
+				case ".splat":
+				case ".spz":


Looks like .sog is supported too as proved in this example: https://playground.babylonjs.com/?inspectorv2=true#QA2662#12

julien-moreau · 2026-06-27T13:29:08Z

+					// their own material and quad geometry when parsed (the loader skips importing geometry for
+					// them). So the serialized material and geometry references are unused: dropping them avoids
+					// writing/delay-loading a useless `.babylonbinarymeshdata` file for the splatting quad.
+					if (isGaussianSplattingMesh(meshToSerialize)) {


In declas.ts I get this error: TypeError: Cannot read properties of null (reading 'scripts')
I added a gaussian splat in a fresh new projet and just saved. Not linked to this line but it's when saving

bobicloudvision added 5 commits June 24, 2026 13:12

bobicloudvision mentioned this pull request Jun 24, 2026

Add a Gaussian Splatting #841

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Add Gaussian Splatting support (.ply / .splat / .spz)#892

Add Gaussian Splatting support (.ply / .splat / .spz)#892
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bobicloudvision:feat/gaussian-splatting

bobicloudvision commented Jun 24, 2026 •

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bobicloudvision commented Jun 24, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Summary

Changes Made

Import

Scene graph & inspector

Rendering correctness

Save & Load

Export & Runtime

Benefits

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julien-moreau commented Jun 24, 2026

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bobicloudvision commented Jun 24, 2026 •

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