Feature Description

The Build Scene Tile command is used to create tile files for the entire selected scene. This function does not depend on a scene, meaning it can be used directly even without an open scene window.

When building scene tiles, mosaic datasets and image datasets correspond to generating image tiles, and terrain datasets correspond to generating terrain tiles. If it is a tile layer (such as a model tile layer) or a KML layer, it remains unchanged.

After the scene tiles are generated, a new workspace and several tile file folders will be created in the result path. The new workspace not only saves the various newly generated tile layers but also stores the style information of each tile layer. By default, the newly generated workspace has the same name as the scene used for generating tiles. Users can specify the names of the generated workspace and scene through the set parameters option.

Using this function requires the computer to meet certain software and hardware requirements, which are consistent with the requirements for using the 3D scene rendering engine. For details, see the 3D Scene Rendering Engine feature description (for Windows and Linux systems).

Function Entry

• Workspace Manager -> Context menu of a specific scene -> Generate Scene Tiles... command

Operation Steps

1. In the Workspace Manager, right-click a scene, select "Generate Scene Tiles..." from the pop-up menu, and the "Build Scene Tile" dialog box will appear.
2. Toolbar
   • Select All: Select all datasets in the data list for batch operations, such as deleting and batch setting tile parameters.
   • Invert Selection: Select the datasets that are not selected in the data list.
   • Delete: Remove the dataset from the current data list.
     Note:

     • When batch setting tile parameters, you must press the Enter key after typing specific parameter values for the changes to take effect; otherwise, the batch assignment of the same parameter values may not work.
3. Data List Area:
   • Dataset: Displays the name of the data used to generate model tiles and upload.
   • Data Source: Displays the name of the data source where the data used to generate model tiles and upload is located.
   • Tile Type: Displays the type of scene tile to be generated. Tile Type is a drop-down button. The drop-down list shows all tile types supported by the selected data, from which the user can choose.
   • Scene Type: Displays the scene type of all generated scene tiles. Scene Type is a drop-down button. The drop-down list shows all scene types supported by the selected data, from which the user can choose.
4. Basic Settings:
   • Scene Name: Enter the tile name in the text box to the right of "Scene Name:", which is the name of the tile root directory. The default name is the scene name.
   • Storage Path: Enter the export directory for the tiles in the text box to the right of "Storage Path". You can also use the "Browse" button after the text box to select the path.
5. Advance Settings:
   • Texture Compression Method: For tiles used for different purposes, the application will adopt different texture compression methods to reduce the amount of video memory used by texture images.
     • WebP: Significantly reduces the total data volume, a texture compression format supported by both PC and mobile devices.
     • DXT (PC Device): Reduces video memory usage and improves rendering performance, but the total data volume will increase.
     • CRN_DXT5 (PC): Reduces video memory usage and total data volume, but requires longer processing time.
     • No Compression: Performs no texture compression.
   • Tile Side Length: Displays and sets the size of the tile side length in meters. Different tile side lengths correspond to different scales. When the data is dense and the geometry and textures are simple, the tile side length can be set to a larger value, such as 1000. When the data is sparse or the geometry or textures are complex, the tile side length can be set to a smaller value, such as 200.
   • Filter Threshold: Used to improve the performance of large scene data by filtering out sub-objects with smaller coarse layers. For example, if the filter threshold is set to 2, sub-objects with a longest side smaller than 2 meters are filtered out in the coarsest layer, sub-objects smaller than 1 meter are filtered out in the second coarsest layer, and so on. Sub-objects in the finest layer are not filtered.
   • S3M Version: Used to set the tile version, including: S3M 3.0, S3M 3.01.
     • S3M 3.0: The geographic coordinate system adopts an ellipsoid datum. Based on 2.0, it adds support for MeshOpt Compression vertex optimization mode, KTX 2.0 texture compression format, OBB bounding boxes, PBR Material with semantic textures and mask textures, multiple LOD switching modes, skeletal animation, vertex attributes expressing more dimensions, and pixel-level semantic information for textures.
     • S3M 3.01 (Recommended): The geographic coordinate system adopts an ellipsoid datum. Based on 3.0, it fully adapts to the CH/T 9040 industry standard and provides various open resources for data parsing or format conversion (address: https://github.com/SuperMap/s3m-spec). It upgrades the attribute data storage structure (DB large files), supports expressing BIM component tree information, and supports expressing multi-temporal and multi-feature characteristic values.
   • Property Storage Type: Supports two types: S3MD and Attribute.
     • S3MD: Stores attribute data in JSON format, allowing for quick extraction of all attributes of a single object.
     • Attribute: Stores attribute data in binary stream format, more suitable for data with many attributes, and allows for quick extraction of attributes for specified fields of multiple objects.
   • Object ID Field: Select the property field used for the unique identifier Object ID. The default value is SmID. If you need to update tile data, please use SmUserID or another unique identifier. Avoid using non-unique identifiers like SmID to prevent update failures.
   • Repeat Map Group, Point-Attached External Models to S3M, Recalculate Normals, Instancing, Tangent: Check these options as needed.
     • Repeat Map Group: Used to set whether to repeat the map group. During the modeling process, a large number of repeated textures are often used on a single building. For example, railings and guardrails on different floors often have the same appearance. Sharing a single texture can significantly reduce performance and resource consumption.
     • Point-Attached External Models to S3M: Checked by default. Supports generating point-attached external models as 3D tiles. If the attachment is an image, it is recommended to uncheck this option.
     • Recalculate Normals: Used to set whether to recalculate normals. If the data normals are incorrect, this option can be checked. Surface normals are important properties of a geometry's surface, mainly used to produce lighting effects that conform to visual habits during rendering. When rendering tiles, the model's own normals can be used.
     • Instancing: Used to set whether the result data uses instanced storage. Instanced storage means that if objects are reused, only one object needs to be stored in memory, and for reused instances, only positional and rotational/scaling pose information needs to be recorded.
     • Tangent: Used to set whether the result data has tangents. When checked, indoor mapping technology can be applied to the resulting S3M data in Unreal Engine to simulate indoor effects.
6. "Auto Close When Finished" and "Show Progress Bar" are checked by default and can be unchecked.
7. After completing the settings, click the "OK" button to execute the scene tile generation operation.

Differences from Building 3D Tiles

The context menu provides two ways to build 3D tiles. One is to build 3D tiles through the "Generate 3D Tiles..." command in the dataset's context menu, and the other is to generate tiles for all data in the entire scene tile through the "Generate Scene Tiles..." command in the scene's context menu. The two methods differ in operation mode and generated results. Please use them appropriately in practical applications.

The differences between the two are as follows:

1. The "Generate 3D Tiles..." command is located in the context menu of the dataset node in the Workspace Manager; the "Build Scene Tile" command is located in the context menu of the scene node in the Workspace Manager and requires that a scene must exist in the current workspace.
2. "Generate 3D Tiles..." allows you to manually add data for generating tiles; the entire scene tile can only generate tiles for existing datasets in a specific scene and cannot add other datasets that do not exist in the scene.
3. To view the results of generated 3D tiles, you need to open the tile file corresponding to each layer individually; the entire scene tile generates a workspace that saves the styles of each layer in the scene. To view the generated results, you only need to open the workspace of the entire scene tile, and its styles will be displayed.