HavObservatoriet (“sea observatory”) is a public space which displays a simulation of the current sea conditions around Denmark

HavObservatoriet (“Sea observatory”) is an installation produced in response to a commision from Vejle Kommune and Statens Kunstfond (the Danish arts council) for a permanent scuptural data work for the new Klima Park (“Climate park”) in the town.

We designed a 3m high, 7m diameter circular steel building which contains a giant panoramic screen on which is displayed a real time simulation of ocean waves. The building is intended as a meditative space within the park, sheltered from the wind and weather, but connected to the power of the ocean..

The system is connected to the latest ECMWF near-term ocean wave spectrum forecasts, which predict the sea state around the world. We convert the spectral data from these forecasts into an animated simulation of the ocean surface, and then render this surface using a non-photorealistic particle-based rendering system. The screen shows the “view” from a single location at a time, changing the location every few minutes to a new semi-random location around the coast of Denmark. Sometimes the screen will be showing 10m high storm surge from the north sea, sometimes the tranquil waves from the east coast of Jutland.

The building surrounds the viewer in a panoramic image of the sea, which is displayed at 1:1 scale - so a 1m high wave appears 1m high on the screen. Because the screen wraps around the viewer, you can see a wave approaching from one direction, feel it wash over the building, and then disappear in the opposite direction. The slow rhythmic movement of the waves is surprisingly calming - even during very rough seas. No one has been seasick, yet.

Jean Bidlot : example wave spectra from the seas around denmark

Software development

To develop the ocean wave simulation we worked (again!) with ECMWF (who generously provided access to their data free of charge), and specifically with senior scientist Jean Bidlot, who helped us to understand the intricacies of ocean wave spectra, provided us with example data, patiently answered all of our naive questions, and inspired us with his humour and love of the subject.

We would also like to thank Christopher Horvath for his paper Empirical directional wave spectra for computer graphics, on which most of the wave surface generation code is based.

In developing the project we were acutely aware of the power requirements of running a large LED screen for long periods of time. In response we developed a rendering technique that only requires a small proportion of the screen to be illuminated at any one time. Most of the the image is black, and so requires very little power. In addition the entire display is responsive to ambient light conditions, dimming the image when possible to save power.

The animation and rendering systems were proptotyped in Houdini, and then written as shaders in HLSL and Unity. We wrote the streaming data processing pipeline for converting the ECMWF forecasts into animation data in Scala.

Construction

We previsualised the building and screen characteristics using a parametric system developed in Houdini and exported as USD for VR visualisation. We did the detailed structural design and engineering analysis in Solidworks, and later re-modelled it in Fusion360 for manufacturing.

The fabrication of the building itself was done by InMetal a/s a local metal fabricator who were able to do the precision laser cutting and bending work required for the steel design. InMetal were able to complete the work to a very tight budget and deadline, and were extremely responsive to our changing requirements. Thanks espoecially to Jesper Wulff from InMetal, who personally sheparded us through the process.

The screen is supplied by Immediad Group. It is a based on a flexible 250mm x 250 mm module, with 2.9mm pixel pitch. Immediad were one of the few Danish suppliers able to provide a flexible display - essential for the curved screen we had planned. Martin and Torben from Immediad worked heroically to help us screw in the nearly 5000 screws required to connect the LED modules.

Engineering consultancy was provided by Leonardo Battezini at OJ Rådgivende Ingeniører A/S who verified that our design wouldn’t sink into the swamplike soil of the Klimaparc.

An early prototype of the particle based wave rendering system

Early previsualisations of the structure, and cutaway view of the construction

Acknowledgements

HavObservatoriet is the first of a series of Danish Arts Foundation commissioned artworks in Vejle, with a focus on water as a future challenge and potential.

HavObservatoriet is part of the area renewal programme in Vejle Midtby Øst and is supported by the regional renewal funds of the Danish Social and Housing Authority.

HavObservatoriet is supported by European Centre for Medium-Range Weather Forecasts (ECMWF) and the Art, Design and Media Research Centre at Sheffield Hallam University (ADMRC)

We would like to thank all of the companies involved in the construcion of the project :

InMetal A/S

Immediad Group

T Jarle APS

Winther & Trolle APS

HETEK A/S

OJ Rådgivende Ingeniører A/S

Hundsbæk & Henriksen A/S

Sonny Olesen Smede og Maskinteknik