geometry.bin file struct

[kangweigang]

hello! thans for the brief description of the geometry.bin file, can I know the detail information of the file ?e.g. struct?

[chri7928]

Hello,

Does this help? https://github.com/Esri/i3s-spec/blob/master/format/Indexed%203d%20Scene%20Layer%20Format%20Specification.md#_6_7

Also, I would recommend downloading and inspecting a SLPK such as this one: https://www.arcgis.com/home/item.html?id=ecb909417e1e4b36b2db9c7de14f3575

Let us know if you need more information.

[kangweigang]

hello, I want to know the struct of the geometry.bin file in the slpk file . e.g.: 1-8 byte is count is a int32.

  header and body.

 thanks。

[sreinhard]

Hello

The layout of the binary format is defined by the defaultGeometrySchema on the service. For example, the default layout we are using is defined as follows:

"defaultGeometrySchema": {
  "geometryType": "triangles",
  "topology": "PerAttributeArray",
  "header": [
    {
      "property": "vertexCount",
      "type": "UInt32"
    },
    {
      "property": "featureCount",
      "type": "UInt32"
    }
  ],
  "ordering": [
    "position",
    "normal",
    "uv0",
    "color"
  ],
  "vertexAttributes": {
    "position": {
      "valueType": "Float32",
      "valuesPerElement": 3
    },
    "normal": {
      "valueType": "Float32",
      "valuesPerElement": 3
    },
    "uv0": {
      "valueType": "Float32",
      "valuesPerElement": 2
    },
    "color": {
      "valueType": "UInt8",
      "valuesPerElement": 4
    }
  },
  "featureAttributeOrder": [
    "id",
    "faceRange"
  ],
  "featureAttributes": {
    "id": {
      "valueType": "UInt64",
      "valuesPerElement": 1
    },
      "faceRange": {
      "valueType": "UInt32",
      "valuesPerElement": 2
    }
  }
}

this corresponds to the following binary layout (in c pseudo struct):

// header
uint32 vertexCount;
uint32 featureCount;

// vertex attributes
float32 position[3 * vertexCount];
float32 normal[3 * vertexCount];
float32 uv0[2 * vertexCount];
uint8 color[4 * vertexCount];

// feature attributes
uint64 id[featureCount];
uint32 faceRange[2 * featureCount];

Please let me know if you need more information.

[kangweigang]

@sreinhard
Thanks for your answer, now I know the struct of the .bin file. I can read it , convert to position and other infomations. Thanks everybody!

[CrashedBboy]

Hi,
I'm wondering those values in the binary file are little-endian or big-endian?

[sreinhard]

@CrashedBboy all binary data is little-endian.