Bentley ContextCapture Oblique

This page describes the original Bentley ContextCapture oblique mapping resources for Orbit import.

Use the corresponding Orbit Import Template to import the described original data.
It is recommend to read first Orbit Mapping Resource.

Oblique Images

Image files

Image type : Preferably undistorted (corrected distortion and Central Principal Point) planar images.
File format : Each image is one *.tif file.
File name : Corresponds to the name in the image positions file, see below.

Image Positions File and Camera Calibration

*.xml Bentley export X-right Y-down Yaw, Pitch, Roll angles
Camera calibration information is included in the Bentley export.

Value of Coordinates “X;Y;Z” : Any supported coordinate system, decimal notation, without thousands separator.
Value of Angles “Yaw, Pitch, Roll” : Supported Mapping Resources, degrees.
File format : One *.xml file for all cameras having <Photogroup></Photogroup> tag enclosing all images taken with one camera.

To import multiple cameras it is necessary to do some minimal manual editing of the *.xml file exported from Bentley: starting from the 2nd Photogroup the name\ID of the Photogroup should be included in the tag <Photogroup> (opening and closing) and every Photogroup has to correspond to a camera and will be placed in a separate planar folder.
So the first <Photogroup> tag stays the same, second should is changed into <Photogroup-2>, 3rd into <Photogroup-3> and so on.
In case there is only one camera in the project no editing has to be done!

<?xml version="1.0" encoding="utf-8"?>
<BlocksExchange version="3.2">
	<SpatialReferenceSystems>
		<SRS>
			<Id>0</Id>
			<Name>WGS 84 / UTM zone 36N (EPSG:32636)</Name>
			<Definition>EPSG:32636</Definition>
		</SRS>
	</SpatialReferenceSystems>
	<Block>
		<Name>Block_20 (merged block) - AT no color - AT rigid - AT</Name>
		<Description>Result of aerotriangulation of Block_20 (merged block) - AT no color - AT rigid (2018-Apr-17 18:36:18)</Description>
		<Type>Aerial</Type>
		<SRSId>0</SRSId>
		<Photogroups>
			<Photogroup>
				<Name>Photogroup 1</Name>
				<ImageDimensions>
					<Width>4864</Width>
					<Height>3232</Height>
				</ImageDimensions>
				<CameraModelType>Perspective</CameraModelType>
				<CameraModelBand>Visible</CameraModelBand>
				<FocalLength>405.922840835919</FocalLength>
				<SensorSize>48.64</SensorSize>
				<CameraOrientation>XRightYDown</CameraOrientation>
				<PrincipalPoint>
					<x>2243.31129670427</x>
					<y>1558.26631705849</y>
				</PrincipalPoint>
				<Distortion>
					<K1>-0.190265209845049</K1>
					<K2>1.12316439250243</K2>
					<K3>0.00875215058070689</K3>
					<P1>-9.14796e-05</P1>
					<P2>-0.000529222</P2>
				</Distortion>
				<AspectRatio>1</AspectRatio>
				<Skew>0</Skew>
				<Photo>
					<Id>0</Id>
					<ImagePath>U:/Data/wwwroot/Files/Orbit/Arara/281474976845088_1.tif</ImagePath>
					<Component>1</Component>
					<Pose>
						<Rotation>
							<Yaw>96.7390400290272</Yaw>
							<Pitch>-81.2759334494381</Pitch>
							<Roll>-175.637035185076</Roll>
						</Rotation>
						<Center>
							<x>693470.245763582</x>
							<y>3449436.37256463</y>
							<z>2493.59170858562</z>
						</Center>
					</Pose>
					<NearDepth>1354.14883099397</NearDepth>
					<MedianDepth>2043.12711992778</MedianDepth>
					<FarDepth>2256.82995800756</FarDepth>
					<ExifData>
						<ImageDimensions>
							<Width>4864</Width>
							<Height>3232</Height>
						</ImageDimensions>
						<Make>Adobe Systems Inc.</Make>
						<Model>Tiff File</Model>
					</ExifData>
				</Photo>
				<Photo>
				...
				</Photo>

			</Photogroup>
			<Photogroup-2>
			...
			</Photogroup-2>
		</Photogroups>

LiDAR or Point Cloud generated by Dense Matching (optional)

Point cloud files

File format : One or more *.las or *.laz files.
File structure : Las version 1.2.
Value of Latitude, Longitude, Elevation : Same CRS as Image Positions.

DEM (optional)

Raster file

File : one *.tif file with corresponding *.tfw
Naming : free of choice
Crs : Any supported projected coordinate system can be used, but all imported oblique resources should have the same crs.