Collider mesh: measurement and precise clicks on splat scenes
A Gaussian Splat looks solid, but it isn't: it's millions of soft, partly see-through points of color, with no surface you could put a ruler on. A collider mesh gives it one. It's an ordinary 3D mesh of the same place — exported from the app or photogrammetry project your splat came from — that you upload next to the splat. Visitors never see it; Kroscloud keeps it as an invisible surface under the splat. With it, every click — focusing the camera, placing a point of interest — lands exactly on the surface, and on Business plans visitors can also measure distances, read height profiles and draw contour lines on your scene. This page explains where to get a mesh that fits, how to prepare and align it, and what changes for your visitors.
- Export a mesh of the same capture, from the same project as your splat.
- Simplify it to a few hundred thousand triangles, drop the textures and save it as an
uncompressed
.glb. - In the editor, open Collider mesh, upload the file and check that the wireframe lines up with the splat — turn it with the rotate buttons if it doesn't.
- On Business and Enterprise, open the Measurement menu, choose the mesh's unit and switch measurement on.
What the collider mesh changes
Every splat scene already has a simple click surface that Kroscloud builds automatically from the splat. It's good enough to fly the camera to the spot a visitor double-clicks, but too approximate to measure on. A collider mesh replaces it with your project's real geometry:
| Without a collider mesh | With a collider mesh | |
|---|---|---|
| Measurement, height profiles, contour lines | Not available. | Available to visitors once you switch measurement on (Business and Enterprise). |
| Double-click to focus the camera | Lands on the automatic surface, which covers the main scanned subject. A double-click on the distant surroundings resets the view. | Lands exactly on the mesh, wherever the mesh reaches. A double-click off the mesh resets the view. |
| Placing points of interest and GPS reference points (editor) | On the automatic surface. | On the mesh. |
| Live GPS position of visitors on site | The marker sits on the automatic surface. | The marker sits on the mesh. |
| What visitors see | Your splat. | Your splat. The mesh is never drawn. |
| Loading | Unchanged. | The mesh downloads first, before the splat — so keep it small. |
Why the mesh must come from the same project
Kroscloud doesn't move or resize the mesh to fit your splat. It places the mesh in the splat's own coordinates, exactly as you exported it; the only correction you can make is turning it in 90° steps. So the mesh has to share the splat's position and scale — in practice, it has to come from the same capture or the same photogrammetry project. A mesh of the same place from a different scan, or a model built by hand, won't line up.
Kroscloud doesn't generate a collider mesh from your splat either. The tool that made your splat already has the real geometry, and a mesh exported from it is far more accurate than anything rebuilt from the soft splat points.
Where to get a mesh that lines up
Several capture apps and photogrammetry tools can give you a splat and a matching mesh from one capture. Tools change quickly, so check your tool's current export options:
| Tool | How to get the mesh |
|---|---|
| Polycam | Export the same capture both as a splat and as a mesh (glTF / GLB). |
| Scaniverse | Scaniverse can produce a mesh of the same scan alongside the splat. Export it and convert it to
.glb if it comes in another format (Blender can import USD/USDZ files, for example). |
| KIRI Engine | Its mesh-inclusive splat captures export a mesh of the same capture, GLB among other formats. |
| 3DF Zephyr | Builds the splat and the mesh in the same photogrammetry project — export both from that project. |
| RealityScan (RealityCapture) or Agisoft Metashape, with a splat trainer such as Postshot, LichtFeld Studio or Brush | Train the splat from the project's export for splatting (COLMAP format) and export the mesh from the same project, in the same local coordinate system. RealityScan's export for splatting is a quarter turn about the X axis away from its mesh exports: either export the mesh with Rotation X = 90 in RealityScan's export dialog, or fix it later with one click of the rotate buttons in Kroscloud. |
- The trainer re-centered or rescaled the scene. Some training tools normalize the scene by default — nerfstudio's splatfacto and gsplat's example trainer, for instance. The splat then no longer shares the project's coordinates. Turn the normalization off before training, or use a tool that keeps the coordinates as they are.
- The two exports use different coordinate settings — for example the mesh in geographic (map) coordinates while the splat was trained in the project's local coordinates. Export both with the same setting.
- The project changed between the two exports. Export the mesh after the alignment, ground plane and scale of the project are final.
- The splat was moved after training. Moving, rotating or scaling the splat in an editor such as SuperSplat puts it in different coordinates from the mesh. Cropping and deleting points is fine. The scene orientation you set in Kroscloud's editor is fine too — it turns the mesh together with the splat.
Prepare the mesh
The collider mesh is only there to be measured and clicked on, so it can be much lighter than the model you would show. These are the requirements:
| Requirement | Details |
|---|---|
One binary .glb file |
With all its data embedded. A .gltf with a separate .bin file isn't
accepted — choose "glTF Binary (.glb)" when exporting. |
| Uncompressed | No Draco compression, no meshopt and no mesh quantization. Kroscloud reads the plain triangles. |
| A triangle mesh | A point cloud or a set of lines can't be measured on. Any number of separate meshes in the file is fine. |
| Small | Aim for a few hundred thousand triangles — a file of a few MB (around 200,000 triangles is typically 3–5 MB without textures). Stay well under 1 million vertices. The hard limits are 100 MB and 10 million triangles, but a mesh anywhere near them makes your scene slow to open for every visitor. |
| No textures or colors needed | The mesh is never shown, so strip textures and materials — they only make the file bigger. |
| Covers what visitors will use | Areas outside the mesh can't be measured, and a double-click there resets the view. Include the ground and surroundings visitors are likely to measure or click. |
| Real-world units | Metres are the simplest. You tell Kroscloud the mesh's unit in the Measurement menu — or let it take the scale from your GPS reference points. |
The collider mesh counts toward your account's storage, like the scene's other files.
Upload and align it in the editor
1. Upload the mesh
Open your splat scene in the editor and click Collider mesh in the top menu. Click Upload collider mesh (.glb) and choose your file. Kroscloud checks the file while it uploads; if it can't use it, the menu tells you why (see Troubleshooting). When it's done, the menu shows Collider: uploaded with the file size.
2. Check the fit with the wireframe
While the Collider mesh menu is open, the mesh is drawn as a wireframe over your splat. Orbit around and look from the side and from above: walls, edges and the ground of the mesh should sit on the same surfaces in the splat. The wireframe disappears again when you close the menu — visitors never see it.
3. Turn it if it doesn't fit
Meshes from some tools arrive turned on their side or upside down, because tools disagree about which axis points up. Under Orientation (90° steps) the menu shows the same three axis icons as the scene orientation dialog, each with a + and a − button that turn the mesh a quarter turn about that axis. Combine turns until the wireframe fits — any axis-aligned orientation can be reached. Every click is saved immediately; the menu shows Current: rotated, and Reset returns the mesh to how you uploaded it.
4. Switch measurement on (Business and Enterprise)
On Premium the collider mesh is now in place, and clicks land on it — you're done. On Business and Enterprise, click Open Measurement menu at the bottom of the Collider mesh menu (or Measurement in the top menu):
- Measurement — the switch that turns the tools on for visitors. It's available once a collider mesh is uploaded.
- Model Unit — the real-world unit of one unit of the mesh: Metric (cm, m, km) or Imperial (in, ft, yd, mi). Most capture and photogrammetry tools export metres.
- Use GPS distances (metres) — if the scene is georeferenced with all three GPS reference points, Kroscloud can take the scale from the GPS points instead of the model unit. Use it when your capture has no reliable real-world scale. The scale comes from the distance between points A and B, so place them far apart and precisely.
More on these settings: Measurement in the editor guide.
What your visitors see
- A slightly longer loading screen. The collider mesh downloads before the splat, and the loading screen shows Downloading collision mesh with the megabytes. A mesh of a few MB adds a moment; a large one keeps every visitor waiting.
- Two extra buttons in the viewer when you switch measurement on (Business and Enterprise):
Measurement (a ruler) and Contour lines.
- Measurement — visitors click points on the scene (up to 20) and see the direct, horizontal and vertical distances. Show results opens a table for every segment and a height profile: the height of the surface along the measured path, relative to the first point, which visitors can download as an image. They can switch the displayed units between metric and imperial.
- Contour lines — a click draws a contour line that traces the surface at that height; visitors add more lines above or below and choose the vertical distance between them.
- Precise double-clicks. Double-clicking flies the camera to the exact spot on the mesh.
- Never the mesh itself. On protected scenes the mesh is protected like the splat: only visitors who unlocked the scene can download it.
Replace, download or delete the mesh
- Replace collider mesh (.glb) uploads a new version. The rotation you set is kept — click Reset if the new export already fits as it is. Visitors get the new mesh the next time they open the scene.
- Download gives you the uploaded
.glbback. - Delete removes the mesh. Measurement and contour lines are switched off for the scene, and clicks go back to the automatic surface. Delete works on every plan — on Free it's how you enable a scene again that was disabled because of its mesh (see below).
- Replacing the splat itself with Update source file keeps the collider mesh and its rotation. Export the new splat from the same project, so it stays in the same coordinates as the mesh.
How accurate are the measurements?
The numbers come from the mesh, not from the splat — the splat is only the picture. So measurements are as accurate as your mesh and its fit:
- The mesh itself — the accuracy of your photogrammetry or scan, and its real-world scale (or the accuracy of your GPS reference points, when you use GPS distances).
- The fit to the splat — visitors click what they see in the splat, but the point is taken on the mesh at that spot. If the mesh sits slightly off the splat, a click on a corner in the splat measures the mesh next to it. Check the wireframe from several angles.
- The model unit — a wrong unit scales every distance by the same factor (for example 100× for centimetres versus metres).
Troubleshooting
| Problem | What to do |
|---|---|
| The upload button is disabled and the menu says the feature is available only for Premium and Business accounts | The collider mesh is part of Premium and higher plans; measurement needs Business or Enterprise. Compare plans. |
| My splat scene is disabled after my account moved to the Free plan | The Free plan doesn't include the collider mesh. Open the scene in the editor and delete the mesh in the Collider mesh menu — the scene is enabled again straight away, unless something else on it is also beyond the Free plan (for example more points of interest than Free allows). Or upgrade to Premium to keep the mesh. |
| not a GLB file (bad magic — export as binary .glb, not .gltf) | The file isn't a binary glTF. Export again as "glTF Binary (.glb)". |
| GLB requires glTF extensions (e.g. Draco compression) | Turn off Draco compression, meshopt and mesh quantization in the exporter and export again. |
| GLB must embed its data… | The file points to a separate .bin or another file. Export one self-contained
.glb. |
| GLB contains no triangle meshes | The file holds a point cloud or lines. Export the mesh (the triangulated model) instead. |
| …the collider limit is 100 MB or …exceeds the 10 M triangle collider limit | Simplify the mesh (for example with Blender's Decimate modifier) and strip textures, then export again. Aim for a few MB. |
| corrupt GLB… or unsupported mesh data… | The exporter wrote something Kroscloud can't read. Export again without compression or quantization; if it still fails, open the file in Blender and export it from there. |
| The file is too large (or your storage quota is exhausted) for a file under 100 MB | Your account's storage is full — the mesh counts toward it. Free up space or upgrade your plan. |
| The wireframe doesn't line up with the splat | Try the rotate buttons first — quarter turns about X are the most common fix. If it's in the wrong place, the wrong size or mirrored, re-export the mesh from the same project as the splat (see When the mesh won't line up). |
| The Measurement switch is disabled | Upload a collider mesh first — the Measurement menu then shows Collider mesh: uploaded. The switch also needs a Business or Enterprise plan. |
| Visitors don't see the measurement buttons | Check that measurement is switched on. If Use GPS distances is on, all three GPS reference points must be set, with A and B at different places — otherwise the buttons stay hidden. |
| Distances are off by a constant factor | The model unit doesn't match the unit the mesh was exported in. Set the right unit in the Measurement menu, or use GPS distances. |
| My scene takes a long time to open since I added the mesh | The mesh downloads before the scene shows. Simplify it to a few MB and replace it — measurements barely change. |
| A double-click resets the view instead of flying to the spot | The click missed the mesh. Export a mesh that also covers the areas visitors click. |
Frequently asked questions
Do I need a collider mesh?
Only if you want measurement, height profiles and contour lines, or clicks that land exactly on the surface. Everything else — points of interest, audio, GPS, sharing and embedding — works without one.
Which plans include the collider mesh?
Premium, Business and Enterprise. On Premium it makes double-clicks and point placement land exactly on the surface; measurement, height profiles and contour lines on top of it are part of Business and Enterprise. Free accounts can't upload one.
What happens to my collider meshes if I move to the Free plan?
Like other features the Free plan doesn't include, a splat scene with a collider mesh is disabled: visitors can't open it, and My board marks it as disabled. To enable it again, open it in the editor and delete the mesh in the Collider mesh menu, or upgrade to Premium or higher.
Will visitors see the collider mesh?
No. Visitors only ever see your splat. The wireframe appears only in your editor, while the Collider mesh menu is open.
Does the collider mesh stop visitors from moving through walls?
No. Despite the name, it doesn't limit where the camera can go — it's the surface for measuring and clicking.
Can Kroscloud make the mesh from my splat?
No. Upload a mesh from the app or photogrammetry project your splat came from — it has the real geometry.
Can I move or scale the mesh in Kroscloud?
No, only turn it in 90° steps. Position and scale have to come from the export, which is why the mesh must come from the same project as the splat.
Does the collider mesh change how sharp my splat looks?
No. It only adds a download before the scene appears. How the splat itself is shown on each device is explained in Full detail and streaming.
Measure on your splat scenes
The collider mesh comes with Premium; measurement, height profiles and contour lines with Business.
Compare plans Upload your first splat scene