Virtual Aquarium: Mixed Reality Consisting of 3DCG Animation and Underwater Integral Photography
- 1.3k Downloads
Abstract
Virtual aquariums have various advantages when compared with real aquariums. First, imaginary creatures and creatures that are difficult to maintain in real aquariums can be displayed. Second, virtual aquariums have similar soothing effects as an actual aquarium. Therefore, we developed a new virtual aquarium through integral photography (IP), wherein virtual fishes are created with 3DCG animation and real water. Stereoscopic view is possible from all directions above the water tank through the IP and without the need for special glasses. A fly’s eye lens is sunk in the water resulting in larger focal length for the fly’s eye lens and an increase in the amount of popping out. Therefore, a stronger stereoscopic effect is obtained. The displayed fishes appear to be alive and swimming in the water, an effect achieved through three-dimensional computer graphics animation. This system can also be appreciated as an artwork. This system can also be applied to exhibit already-extinct ancient creatures in aquariums or museums in the future.
Keywords
Integral photography Three-dimensional computer graphics Animation1 Introduction
A large number of people keep fishes in their homes and/or offices because of its soothing effect. Recent progress in computer graphics technology has made it possible to create an aquarium using virtual reality. Virtual fish has many advantages compared to real fish. For instance, keeping virtual fishes remove limitations as to the type of fish kept in the tank. From fishes that live deep in the sea to fictional creatures, one’s imagination would be the limit. Fishes that have perished can also be restored and brought back to life.
Concept of our system
2 Related Work
Our virtual aquarium may share similar concepts with a virtual water tank where a display is arranged on one side of the water tank. In such cases however, displaying the creature in water can be difficult.
AquaTop Display: A True Immersive Water Display System [1]: a display that projects two-dimensional (2D) images on the surface of the water clouded with bath salts. In contrast, our study enables the display of a stereoscopic image as if it actually exists in the water and not only on the surface.
Three-dimensional (3D) crystal engraving or Bubblegram [2]: 3D designs are generated inside a solid block of glass or transparent plastic by irradiating a laser beam inside the material. The objects appear to exist inside the block. However, once it is created, changing the shape or moving the object becomes impossible. In comparison, our system enables animating the 3DCG image displayed inside the water.
3 Integral Photography
We adopted an integral photography (IP) in this system because IP is indisputably the most ideal system among various 3D display systems developed to date. IP, which was invented by Lippmann in 1908 and has been improved continuously, has an advantage in that it provides both horizontal and vertical parallax without the need to wear stereo glasses.
Simple integral photography system
Nevertheless, IP has not been widely used until now. One possible reason is that the extremely high initial cost of fly’s eye lens production when produced using a metal mold. Conventionally, because the lens pitch of the fly’s eye lens is considered an integral multiple of the pixel pitch of FPD, the lens should be custom-made according to the pixel pitch of FPD. However, this step can be very costly.
The invention of the extended fractional view (EFV) method [3−5], which is a new method of synthesizing an IP image, drastically changed this situation. In the EFV method, both an integer and an arbitrary real number are allowed as ratio between the lens and pixel pitches. The physical difference between the pitches is processed by software. Therefore, the initial high cost of customizing a fly’s eye lens is reduced because a comparatively inexpensive ready-made fly’s eye lens can be used in combination with various FPDs.
IP is also effective in expressing the glittering effect of a material, such as gems, because the light emitted from each convex lens of a fly’s eye lens depends on its direction [6−8].
4 System Configuration
System configuration.
First, water is essential for imaginary underwater life. This system is a type of mixed reality in which real water and imaginary creatures exist in the same space. In common mixed reality systems, objects created with CG are synthesized with real space using transparent type head-mounted display (HMD). In this system however, IP is used instead of HMD.
A higher reality is provided because the refraction of the light occurs on the surface of the water as shown in Fig. 3.
Refraction on the surface of the water
5 Creating a 3DCG Scene
The 3DCG scene consists of two swimming creature models and water surface textures. The scene is created in Autodesk Maya.
5.1 3DCG Models
Imaginary fish 3DCG model surface.
Bones of imaginary fish 3DCG model.
Rendered imaginary fish 3DCG model
In this scene, two fish models were created and made to appear to exist at different depths. A contrast in positions is necessary to evoke the sense of depth using IP.
5.2 Background
Two layers of water surface.
2D image of water surface
Rendered scene
6 Animation
Animating to show movement is important in this case because it will make the fishes seem alive. This time, the creatures were designed based on real fishes. Swimming fishes repeat similar movements. Therefore their movements have a certain periodicity. This movement is similar to how humans walk, that is, they move mostly by repeating the same movement over and over. By focusing on this point, one cycle of the movements was created and then repeated. This repetition enabled us to save time in calculating for the rendering.
The speed of the animation should not be too fast because it takes time to integrate the views from the right and left eyes and to perceive stereoscopic views. When a movement is too fast, a possibility exists that the amount of popping out will decrease.
Animation cycle of eight frames of fishes swimming
7 Synthesis of IP Image
Process of synthesizing IP images
Synthesized IP image
Hardware setup
8 Conclusion
Photo of the finished product
References
- 1.Matoba, Y., Takahashi, Y., Tokui, T., Phuong, S., Yamano, S., Koike, H.: AquaTop Display: a True Immersive Water Display System, In: ACM SIGGRAPH 2013 Emerging Technologies (2013)Google Scholar
- 2.Wikipedia. http://en.wikipedia.org/wiki/Bubblegram
- 3.Yanaka, K.: Integral photography suitable for small-lot production using mutually perpendicular lenticular sheets and fractional view. In: Proceedings of SPIE 6490 Stereoscopic Displays and Applications XIV, vol. 649016, pp. 1–8. (2007)Google Scholar
- 4.Yanaka, K.: Integral photography using hexagonal fly’s eye lens and fractional view. In: Proceedings of SPIE 6803 Stereoscopic Displays and Applications XIX, 68031 K, pp. 1–8. (2008)Google Scholar
- 5.Yoda, M., Momose, A., Yanaka, K.: Moving integral photography using a common digital photo frame and fly’s eye lens. In: SIGGRAPH ASIA Posters (2009)Google Scholar
- 6.Maki, N., Yanaka, K.: Underwater integral photography. In: IEEE VR 2015 Demo (2015)Google Scholar
- 7.Maki, N., Yanaka, K.: 3D CG integral photography artwork using glittering effects in the post-processing of Multi-viewpoint Rendered Images. In: HCI International (2014)Google Scholar
- 8.Maki, N., Shirai, A., Yanaka, K.: 3DCG Art expression on a tablet device using integral photography. In: Laval Virtual 2014 VRIC (2014)Google Scholar