Get Geometry from BatchedMesh | Three.js | Page 1

gritty wind Jun 11, 2025, 7:27 PM

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Does anyone ever successfully extract geometry from BatchedMesh with .getGeometryRangeAt ? Why isn't there a method getGeometryAt(geometryId) : BufferGeometry?

gritty wind Jun 11, 2025, 7:47 PM

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Get Geometry from BatchedMesh

sacred spoke Jun 12, 2025, 5:42 AM

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when you do addInstance() save the instanceID it returns so you can refer to it later .


const geoId= batchedMesh.addGeometry(geometry)
...
const instanceID=batchedMesh.addInstance(geoId)
batchedMesh.setMatrixAt(instanceID, matrix)
batchedMesh.setVisibleAt(instanceID, false)

i guess this getGeometryAt method is not there since we know what geometry was added at which id already ?

gritty wind Jun 12, 2025, 6:17 AM

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I need export to GLB only meshes selected by user. I have some trouble to extract geometry from BatchedMesh. I am trying to build mesh from getGeometryRangeAt.

sacred spoke Jun 12, 2025, 7:25 AM

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ahh okay ,

console log these two keys

batchedMesh._geometryInfo // key is geometry id and value is the geometry used
batchedMesh._instanceInfo // key is the instance id and value has {"geometryIndex": 0} , use this geometryIndex to get the geometry from the _geometryInfo dictionary

and use batchedMesh.getMatrixAt() to get the transforms used by the geometry

clone the geometry and use geometry.applyMatrix4() to apply the transforms and make a new Mesh from it

gritty wind Jun 12, 2025, 9:45 AM

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So I have found solution of my problem. In geometryInfo it's not really geometry stored (missing normal & position) so I need to retrieve this information from batchedMesh attributes position & normal.

#Get Geometry from BatchedMesh