com.luciad.format.tiled3d.ogc3dtiles

LuciadLightspeedClass TLcdOGC3DTilesModelDecoder

java.lang.Object

com.luciad.format.tiled3d.ogc3dtiles.TLcdOGC3DTilesModelDecoder

All Implemented Interfaces:

ILcdInputStreamFactoryCapable, ILcdModelDecoder

@LcdService(service=ILcdModelDecoder.class,
            priority=20000)
public final class TLcdOGC3DTilesModelDecoder
extends Object
implements ILcdModelDecoder, ILcdInputStreamFactoryCapable

This model decoder decodes 3D Tiles tileset files to an ILcdModel.

Input files

File	Required	Entry point	Description
tileset.json/root.json	x		File containing the root tile metadata as well as links to the sub-tiles/content.
*.json			Files containing sub-tile metadata as well as links to its sub-tiles/content.
*.b3dm			File containing Batched 3D Model data See the B3DM documentation for more information about this file.
*.pnts			File containing batched Point Cloud data See the PNTS documentation for more information about this file.
*.b3dm_lcd_link			File containing the necessary data for converting from OSGB to Batched 3D Model data. Link files are generated while preprocessing the OSGB dataset.
LuciadPC			Directory containing the necessary data for retrieving payloads from a Luciad Point Cloud dataset.

Since all JSON files have the same structure, any of them could be used as entry point. However, only the tile of the JSON file and its children will be decoded.

Supported file transfer protocols

• This model decoder supports all transfer protocols that are supported by the InputStreamFactory of this decoder.

Model structure

• This model decoder creates a model per entry .json file.
• This model decoder returns a single read-only ILcd2DBoundsIndexedModel.

Model descriptor

• When the tile set contains point cloud data (PNTS), the model descriptor will be an ILcdDataModelDescriptor. Although the elements in the model are not data objects themselves, you can still use the data model to access properties of individual points to build expressions for use in styling. Use ILcdDataModelDescriptor.getModelTypes() to obtain the single data type that consists of the properties available in the PNTS data.
• The type name of the model descriptor is "3D Tiles".

Model reference

• The decoder assumes a Geocentric reference system.

Model elements

• Each decoded model contains elements that implement Object.

Sample code

 ILcdModelDecoder decoder = new TLcdOGC3DTilesModelDecoder();

 ILcdModel model = decoder.decode("tileset.json");
 

Performance tips

• Due to the amount of data that can be loaded, the size of the textures can impact performance.
• Since OGC 3DTiles relies on a tree structure to determine which tile to load. This means the way this tree is built can impact performance. An ideal tree has enough level of details to avoid loading highly details at an early stage while loading those when fully zoomed-in.

Thread safety

• The decoding of models is thread-safe, as long as no properties are changed during the decoding.
• The decoded models are thread-safe for read access.

Supported versions and specifications

This decoder supports version 1 of the OGC 3D Tiles specification. Specifically, it supports:

• Decoding tileset.json with full metadata support, including property values and ranges
• B3DM payloads
• Both GLTF 1.0 and GLTF 2.0 in the B3DM payloads
• PNTS payloads

Known limitations

• The source file must be an external tileset (.json) with batched 3D model (.b3dm) or point cloud (.pnts) contents.
• B3DM tiles support is limited to single color-texture.
• B3DM tiles support does not include animations
• B3DM shading is limited to the base color.
• Embedded binary textures are supported. Externally referenced textures are not supported.
• Instanced 3D Model (I3DM) is not supported.
• Composite Tile Model (CMPT) is not supported.
• Complex, hierarchical batch table properties are not supported.

Requirements

• The current implementation requires JRE 1.2 or higher.
• The current implementation requires native libraries.

Additional comments

• Since all JSON files have the same structure, any of them could be used as entry point. However, only the tile of the JSON file and its children will be decoded.

Example: decoding and visualizing OGC 3D Tiles data

    //First create the model
    ILcdModelDecoder decoder =
        new TLcdCompositeModelDecoder(TLcdServiceLoader.getInstance(ILcdModelDecoder.class));
    ILcdModel model = decoder.decode("https://sampleservices.luciad.com/ogc/3dtiles/marseille-mesh/tileset.json");

    //Create a layer for the model using the layer builder
    ILspLayer layer = TLsp3DTileLayerBuilder.newBuilder()
                                            .model(model)
                                            .build();

    //Add the layer to the Lightspeed view (an ILspView)
    view.addLayer(layer);

Since:

2018.0

Field Summary

Fields

Modifier and Type	Field and Description
static String	TYPE_NAME The type name for the decoded models.

Constructor Summary

Constructors

Constructor and Description
TLcdOGC3DTilesModelDecoder()

Method Summary

Modifier and Type	Method and Description
boolean	canDecodeSource(String aSourceName) Checks whether this model decoder can decode the specified data source.
ILcdModel	decode(String aSourceName) Creates a new model from the given data source.
String	getDisplayName() Returns a short, displayable name for the format that is decoded by this ILcdModelDecoder.
ILcdInputStreamFactory	getInputStreamFactory() Returns the input stream factory that is used.
void	setInputStreamFactory(ILcdInputStreamFactory aInputStreamFactory) Sets the input stream factory to be used.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.luciad.model.ILcdModelDecoder

canDecodeSource, decodeModelMetadata, decodeModelMetadata, decodeSource, discoverDataSources

Field Detail

TYPE_NAME

public static final String TYPE_NAME

The type name for the decoded models.

See Also:

Constant Field Values

Constructor Detail

TLcdOGC3DTilesModelDecoder

public TLcdOGC3DTilesModelDecoder()

Method Detail

getInputStreamFactory

public ILcdInputStreamFactory getInputStreamFactory()

Description copied from interface: ILcdInputStreamFactoryCapable

Returns the input stream factory that is used.

Specified by:

getInputStreamFactory in interface ILcdInputStreamFactoryCapable

Returns:

the input stream factory that is used.

setInputStreamFactory

public void setInputStreamFactory(ILcdInputStreamFactory aInputStreamFactory)

Description copied from interface: ILcdInputStreamFactoryCapable

Sets the input stream factory to be used.

Specified by:

setInputStreamFactory in interface ILcdInputStreamFactoryCapable

Parameters:

aInputStreamFactory - the input stream factory to be used.

getDisplayName

public String getDisplayName()

Description copied from interface: ILcdModelDecoder

Returns a short, displayable name for the format that is decoded by this ILcdModelDecoder.

Specified by:

getDisplayName in interface ILcdModelDecoder

Returns:

the displayable name of this ILcdModelDecoder.

canDecodeSource

public boolean canDecodeSource(String aSourceName)

Description copied from interface: ILcdModelDecoder

Checks whether this model decoder can decode the specified data source. It is acceptable for this method to return true for a source name while decode throws an exception for that same source name.

For performance reasons, we strongly recommend that this will only be a simple test. For example: check the file extension of a file, but not that the file exists or contains expected content.

Specified by:

canDecodeSource in interface ILcdModelDecoder

Parameters:

aSourceName - the data source to be verified; typically a file name or a URL.

Returns:

true if this decoder can likely decode the data specified by the source name, false otherwise.

See Also:

ILcdModelDecoder.decode(String), ILcdModelDecoder.decodeModelMetadata(String)

decode

public ILcdModel decode(String aSourceName)
                 throws IOException

Description copied from interface: ILcdModelDecoder

Creates a new model from the given data source.

Specified by:

decode in interface ILcdModelDecoder

Parameters:

aSourceName - the data source to be decoded; typically a file name or a URL.

Returns:

A model containing the decoded data. While null is allowed, implementors are advised to throw an error instead.

Throws:

IOException - for any exceptions caused by IO problems or invalid data. Since decoding invalid data almost always results in RunTimeExceptions (NullPointerException, IndexOutOfBoundsException, IllegalArgumentException, ...) on unexpected places, implementations are advised to catch RuntimeExceptions in their decode() method, and wrap them into an IOException, as illustrated in the code snippet below.

   public ILcdModel decode( String aSourceName ) throws IOException {
      try (InputStream input = fInputStreamFactory.createInputStream(aSourceName)) {
         // Perform decoding ...
      } catch (RuntimeException e) {
         throw new IOException(e);
      }
   }
 

InterruptedIOException - When the thread on which this method is called is interrupted: it is recommended to stop the decoding and throw an InterruptedIOException. This same exception can also be used if the decoder shows UI to the user, and the user cancels the decoding through the UI.

See Also:

ILcdModelDecoder.canDecodeSource(String)