Culmore Square VVM

1. Overview – What are Visually Verified Montages?

“V.V.M’s are a fusion of 3D Computer Generated Imagery and real life photography. True to real-world scale and position, 3D models of buildings are placed accurately within their environment to produce an image for planning or marketing purposes.

Here at Urban 3D, we use an applied and tested method to ensure technical accuracy, and we adhere to the guidelines for Landscape and Visual Impact Assessment (second edition).

V.V.M’s can carry much more weight than standard Photomontage images, as they are carried out using exacting surveying methods, and are endorsed by an Urban 3D methodology report. Urban 3D has worked with architects and developers for over a decade to produce images that do more than satisfy rigorous technical standards. We strive to create images that communicate the benefits and charm of each individual property. Here we take a detailed look at how to create visually verified montages, or views as they are sometimes known.

guidelines for Landscape and Visual Impact Assessment

2. Methodology Overview

Our methodology is consistent with the best practice guide laid out in the second edition of the Guidelines for Landscape and Visual Impact Assessment.

In addition to this we also refer to the new London View Management Framework documents, as a more up-to-date resource for best practice guidelines, with Appendices C and D being particularly useful.

Appendix C focuses on Protected Vistas, and Appendix D focuses on accurate visual representations.

The disciplines employed by Urban3d are carried out to the highest possible levels of accuracy and make use of the latest technology and software available today.

3. Brief

More often than not a brief will come indirectly from the town planner via the architect. Planners may ask for a number of views in different key locations to help remove any concerns arising from a contentious design issue.

With the planning process taking so long these days, some clients have now decided to take the initiative and submit a series of visually verified montages and a methodology report along with the initial architectural submission to help fast track the planning decision.

4. View Selection

In any case, we need our clients to identify the quantity of views required and the vista locations these views are to be taken from. At this point the client can provide us with any additional preferences, such as weather conditions, times of day, along with a copy of the proposed architectural plans.

The views/camera locations are generally selected through a process of consultation with the relevant statutory consultees, planning consultants, architects etc with regard to relevant planning policies and guidelines.

Generally clients will mark up an Ordnance Survey Map with a series of arrows showing the location and direction of required views.

Ordnance Survey Map

5. Equipment-What do we normally use on-site?

  • Qualified and experienced topographical survey team with survey kit.
  • Digital Camera – Pentax IST DL
  • Standard Lens to avoid any distortion (18-55mm)
  • Tripod With Plum Line fixed to the centre lens
  • Spirit Level or Digital Level
  • Proposed Drawings
  • Pen and Paper
  • Spray Paint
  • OS Map
Equipment used survey kit

6. On-Site Methodology. Recording Essential Data and Parameters

When we arrive on site before taking any photographs we start by recording the following data:-

1. Time of Day
2. Weather Conditions
3. Shadow Strength
4. Sun Position

Then we proceed to the specified vista location and set-up our tripod, camera and plum line. We use our digital level to ensure the camera and tripod are set-up true, not banking or tilting in any direction.

The plum line is then hung from the centre of the lens to the ground. Where the plum line strikes the ground we use spray paint to mark a yellow “X”.

The surveyors will later record the exact location of the centre point of the X. We record the height of the camera before moving to the next required vista location, where we repeat the process.

tripod, camera and plum line set-up

7. High Resolution Digital Photography

(The rest of the Points are all explained within the image backgrounds, so re-writing them is impossible.)

High Resolution Digital Photography

We now supply the survey team with the information they need to complete the survey effectively and efficiently.

They are supplied with an OS map identifying where the marked out “X” spots are and the photograph grayed out for clarity showing the points in the space that we need them to survey.. just like the image below. We also ask them to use our reference system to ensure continuity between surveyors and 3D modellers.

For improved accuracy we try to select fixed points in the foreground, mid ground and distance both high and low.

OS map 2

9. Record Survey Data

The survey team should now record the exact location in terms of geographical position and height relative to the proposed building of the following:

1. Reference points A1 to A14 as below.
2. Camera location positions which we marked with an “X” earlier.

OS Map

10. Surveyers Create Auto CAD Drawing

The survey team will use the data gathered on the site to create an topographical AutoCAD drawing. They will overlay their information onto the existing architects site plan.

They will use the same references systems as used on the site and will make all levels relative to proposed structure. They will also plot the centre point of the lens marked out by Urban 3D.

AutoCAD drawing

11. Create 3D Model of Proposed and Existing Survey Points

3D Model of Proposed and Existing Survey Points

12. Match Virtual To Real World Reference Points

With the 3D environment we now match the 3D reference points to the 2D photograph for example – 3D point A1 will be positioned in the same location as point A1 in the photograph.

When all cameras are matched correctly and all points are aligned and positioned correctly the proposed structure shall sit within the photograph in the correct position, orientation and size.

3D reference points to the 2D photograph

13. Add Light, Weather Conditions and Materials

Using the data we collected on site we now match the time of day, weather conditions, sun position, etc. and setup our virtual lighting system to match the real world photograph. We then add materials based on the architectural finishes specification.

3D environment with virtual lighting system

14. Merge Photograph and 3D Image Together

We now have 2 separate layers/images which need to be merged together using Photoshop. The red zone is the exact position and profile of the proposed building. we can now lay our 3D image on top of the photograph. Making good use of Photoshop’s blending techniques we can merge the 2 images together seamlessly.

Merge Photograph and 3D Image Together

15. Resulting Visually Verified Image

We now add trees, plants and people to soften the image and improve/ enhance the existing photograph. This is the end result – A Visually Verified Montage. V.V.M.  Along with the image we also provided our clients with a in-depth methodology report to explain how we arrived at this conclusion.

Visually Verified Montage. V.V.M

To conclude:

Verified montage views are not to be relied upon as statements of fact.  It is impossible to fully verify a view due to many different physical factors.  A photograph captured using an iPhone will appear different to a photograph taken with a 50 mm lens, and both will not exactly mimic what the human eye can see.

A photograph can never truly capture the human visual experience. All images are interpretations.  Verified images are simply a much closer interpretation to what will actually be seen in reality than an artists impression as the image is produced in a way that controls the scaling, position & orientation of the proposed building relative to the cameras position.