Getting started with re.view

Sensori re.view offers a complete solution for the capture of dense on-site imagery, automated creation of 3D environment models, and easy communication using that data.

This document is a guide to the capturing of data, submission for processing, and viewing of the final models. 

If you have any queries, please get in touch using our contact form.

The cameras we recommend for recording video for re.view are the Z Cam E2-M4, E2-S6G, and E2.  They can be used with the Meike 6.5mm f/2 fisheye lens (MFT mount).   Pre-assembled kits are available to rent from Sensori.

Alternatively, you may use other cameras that support the capture of high bitrate video with a fisheye lens, but the results are likely to be of a lower quality than with our recommended equipment.

We also support the use of stitched 360 panoramic video (equirectangular), but this will result in significantly lower quality and will not provide useful results in darker indoor environments.

The scanning targets used by re.view are available to order from Sensori, but you may also print your own.

Origin plate and scale plates are available to download here.  These should be printed at the original print size of the file.  The distance between the centres of the target patterns is exactly 200mm and must be printed accurately.  We recommend printing these on aluminium composite to reduce the risk of movement during outdoor captures. The rectangular scale plates can be printed either single sided or double sided. Single sided is sufficient for most situations.

Control point markers for use with survey points can be downloaded here.  We recommend printing these on 3mm foam. Our standard size for these is 12cm across, but they may be used at any print size. The centre should be cut out as shown below.

Scanning targets

Using the targets

When capturing data of a site there must be known scale targets or survey point targets placed within the scene. These targets are used to set an accurate scale, reduce drift in the final output, and allow for alignment of the model.  We provide both a set of standard scale plates that can be used when accurately surveyed control points are not available, and a set of control point markers which should be used when three or more control points are available.  

We recommend always using surveyed control points when attempting larger captures of over 1000 square metres.

Note: With all markers it is vital they do not move during a scan. They must be stationary to prevent geometric errors in the final model. Do not collect any of the targets until capture of the scan has finished.

Origin and scale plates - easy use

Our standard set of scale plates includes a square origin plate which defines the centre of a local coordinate system for the scan, and eight unique rectangular scale markers which should be placed as evenly as possible around the site.  We suggest trying to ensure the distances between targets are no more than 20 metres to minimise accumulation of drift in the scan. The square origin plate should be placed flat on a level surface. The rectangular scale pair markers may be placed in any convenient location. Leaning them against a wall can help maximise visibility.

Notes on target placement: 

• You might need to secure the targets to the ground or other surface to prevent them moving in the wind for outdoor captures. 

• The origin target can be screwed into place to maintain a consistent coordinate system across multiple scans. 

• Using double sided tape is useful when fixing retro markers to walls, though if left too long this may rip off paint, so take care

Capturing a scan

For focus checks we will adjust this manually as opposed to using an autofocus system. The focus distance should be set as shown in this image, but we recommend looking at the focus peaking provided in the camera’s live view. To do this  

• Stand about 2 metres from an object in the scene and point the camera at the object 

• Move the focus ring left and right, you will see highlighted “peaks” change as you do this 

• During this movement you want to look for a point where there are the most “peaks”, which are shown as highlighted areas, around the object. 

• Once you have found the point where there are the most “peaks” leave the focus ring in that position. 

The focus is now set for the scan.

Walk the site

For improved accuracy on larger captures and around repeating structures such as stairwells you may also use the control point targets without surveyed ground truth positions . These should be placed in locations with good visibility as shown below. It is important that these markers be secured if you are in a windy outdoor environment to prevent them moving during the capture.

Example routes taken during capture

Capture of a control point target

Uploading your data

Register for an account on the Sensori website if you don’t already have one.

Create the project and scene hierarchy.

Create a new scan within the scene

Choose the appropriate survey data option depending on whether you used the origin and scale plates, or surveyed control points.

Upload csv file of control point coordinates if control points were used. See below for more information on the csv format.

Select ‘Fixed Lens’ for the lens type.

Upload the video files from the camera.

An example of the expected csv format for the control point survey data can be seen here. Units should be metres:

Environmental and weather factors

Depending upon the environment you’re capturing and how the weather is there are a few key notes: 

• Wet and shiny surfaces won’t reconstruct well. Be prepared for mirrored areas, pools of standing water, and glassy objects to be deformed in the final model 

• Clean featureless areas, such as painted walls, may also be deformed or not get reconstructed in the final model.

• Dense vegetation, such as grasses and tree branches, will be poorly reconstructed in the model if there is much wind 

Processing of the scan will take between a few hours and 2 days, depending on the length of video you uploaded.