In this third tutorial, we will explain how to include 2d and 3d objects in a layer.

In general, there are two types of layer, the characteristics of each type can be summarized as below in the table. For more information, please check Edit a layer page.

Some developers have asked about the differences between using custom CIWs and 2d images in 3D space, the table below provides some comparisons:

Before diving into the code, please read create 3d objects carefully to learn how to create a good 3d object.

The changes made to implement 2d and 3d objects are:

• MySQL database - Add two tables to the database, namely "OBJECT_Table" and "TRANSFORM_Table".
• PHP code - Add two functions  "Getobject" and "Gettransform" to retrieve object and transform applied to the POI. 

These changes are made based on the sample code from the Second Tutorial . It is a good idea to review the previous tutorials before moving on.

1. Create two separate tables for Object and Transform

Two tables are created to store Object and Transform dictionary defined in GetPOIs-JSON Response , namely "OBJECT_Table" and "TRANSFORM_Table". Each table has its own id field as primary key and a POI id field to store the corresponding POI Id in POI_Table (POI_Table is created in the first tutorial to store POIs info).

The MySQL statement for creating these two tables are:

--
-- Table structure for table `OBJECT_Table`
--

CREATE TABLE IF NOT EXISTS `OBJECT_Table` (
  `ID` int(10) NOT NULL auto_increment,
  `poiID` varchar(255) NOT NULL,
  `baseURL` varchar(255) NOT NULL,
  `full` varchar(255) NOT NULL,
  `reduced` varchar(255) default NULL,
  `icon` varchar(255) default NULL,
  `size` float(15,5) NOT NULL,
  PRIMARY KEY  (`ID`)
) ENGINE=MyISAM  DEFAULT CHARSET=utf8 AUTO_INCREMENT=4 ;

--
-- Table structure for table `TRANSFORM_Table`
--

CREATE TABLE IF NOT EXISTS `TRANSFORM_Table` (
  `ID` int(10) NOT NULL auto_increment,
  `poiID` varchar(255) NOT NULL,
  `rel` tinyint(1) default '0',
  `angle` decimal(5,2) default '0.00',
  `scale` decimal(12,2) NOT NULL default '1.00',
  PRIMARY KEY  (`ID`)
) ENGINE=MyISAM  DEFAULT CHARSET=utf8 AUTO_INCREMENT=4 ; 

An example of how each table looks like is shown as below:

• An example of one object description in "OBJECT_Table" .

•  An example of one transformation in "TRANSFORM_Table".

2. Create function Getobject to retrieve object assigned to a POI

• Use a SQL statement to retrieve object that has the same poi ID as the POI in POI_Table.
• Assign retrieved object information to $poi["object"] array.

// Put fetched object related parameters for each POI into an associative array. The returned values are assigned to $poi[object].
//
// Arguments:
//   poi ; The POI handler.
//   $db ; The database connection handler.
//
// Returns:
//   array ; An array of received object related parameters for this POI.
//
function Getobject( $poi, $db ) {
 
  // A new table called "OBJECT_Table" is created to store object related parameters, namely "baseURL", "full", "reduced", "icon" and "size".
  // "poiID" which shows the POI id that this object belongs to.
  // The SQL statement returns object which has the same poiID as the id of $poi ($poi['id']).
  $sql_object = $db->prepare( " SELECT baseURL, full, reduced, icon, size
                                                  FROM OBJECT_Table
                                                  WHERE poiID = :id
                                                  LIMIT 0,1 " );
                                 
  // Binds the named parameter markers ":id" to the specified parameter values "$poi['id']".                               
  $sql_object->bindParam( ':id', $poi['id'], PDO::PARAM_INT );
    
  // Use PDO::execute() to execute the prepared statement $sql_object.
  $sql_object->execute();
    
  // Fetch the poi object.
  $object = $sql_object->fetchAll( PDO::FETCH_ASSOC );
 
  /* Process the $object result */
 
  // if $object array is empty, return NULL.
  if ( empty( $object ) ) {
 
      $poi["object"] = null;
      
  }//if
  else {
      // Since each POI only has one object. Logically, only one object should be returned. Assign the first object in the array to $poi["object"]
    $poi["object"] = $object[0];
    
    // Change "size" type to float.
    $poi["object"]["size"] = ChangetoFloat( $poi["object"]["size"] );
    
   }//else
   
   return $poi["object"];

}//Getobject

3. Create function Gettransform to retrieve transform applied to the POI

• Use a SQL statement to retrieve transform that has the same poi ID as the POI in POI_Table.
• Assign retrieved transform information to $poi["transform"] array.

// Put fetched transform related parameters for each POI into an associative array. The returned values are assigned to $poi[transform].
//
// Arguments:
//   poi ; The POI handler.
//   $db ; The database connection handler.
//
// Returns:
//   array ; An array of received transform related parameters for this POI.
//
function Gettransform( $poi, $db ) {
 
  // A new table called "TRANSFORM_Table" is created to store transform related parameters, namely "rel", "angle" and "scale"
  // "poiID" which shows the POI id that this transform belongs to.
  // The SQL statement returns transform which has the same poiID as the id of $poi ($poi['id']).
  $sql_transform = $db->prepare( " SELECT rel, angle, scale
                                                        FROM TRANSFORM_Table
                                                        WHERE poiID = :id
                                                        LIMIT 0,1 " );
                                 
  // Binds the named parameter markers ":id" to the specified parameter values "$poi['id']".                               
  $sql_transform->bindParam( ':id', $poi['id'], PDO::PARAM_INT );
    
  // Use PDO::execute() to execute the prepared statement $sql_transform.
  $sql_transform->execute();
    
  // Fetch the poi transform.
  $transform = $sql_transform->fetchAll( PDO::FETCH_ASSOC );
 
  /* Process the $transform result */
 
  // if $transform array is empty, return NULL.
  if ( empty( $transform ) ) {
 
      $poi["transform"] = null;
      
  }//if
  else {
      // Since each POI only has one transform. Logically, only one transform should be returned. Assign the first transform in the array to $poi["transform"]
    $poi["transform"] = $transform[0];
    
    // Change the value of "rel" into boolean value,if the value is NULL, return NULL.
    $poi["transform"]["rel"] = ChangetoBool( $poi["transform"]["rel"] );
    
    // Change the values of "angle" and "scale" to demical.
    $poi["transform"]["angle"] = ChangetoFloat( $poi["transform"]["angle"] );
    $poi["transform"]["scale"] = ChangetoFloat( $poi["transform"]["scale"] );
  }//else
 
   return $poi["transform"];

}//Gettransform

4. In function Gethotspots, Added the following lines to retrieve relevant object and transform for each POI.

// If POI "dimension" =2 or 3, use function Getobject() to return an object associated with the current POI.
          if ($poi["dimension"] == '2' || $poi["dimension"] == '3')
              $poi["object"] = Getobject ( $poi, $db);
      
// If POI "dimension" =2 or 3, use function Gettransform() to return a transform dictionary associated with the current POI.
          if ($poi["dimension"] == '2' || $poi["dimension"] == '3')
              $poi["transform"] = Gettransform ( $poi, $db);

Sample code can be found HERE . With this tutorial, you can already create a layer with actions and 3d objects enabled. For more information on how 2d and 3d objects are rendered on Layar client, please read here .  Enjoy it!