Computer Animation of Creatures in a Deep Sea

Transcription

1 Computer Animation of Creatures in a Deep Sea Naoya Murakami and Shin-ichi Murakami Olympus Software Technology Corp. Tokyo Denki University ABSTRACT This paper describes an interactive computer animation technique of creatures in a deep sea. Specifically, we generate deep sea images viewed from submarine windows. They contain not only deep sea creatures such as Japanese spider crab, nautilus, angler fish, coelacanth, shark etc. but also front and back windows of submarine, a depth meter and a submarine compass. Generated deep sea creatures move around 3 dimensionally. And submarine can be controlled to move up and down, back and forth and left or right turns, interactively. As the generated images can be transmitted through networks such as internet, they can be observed from remote terminals at any time. Experimental results showed that this technique suggests the possibility of constructing an interactive electronic aquarium over internet. Key words: Electronic aquarium, Real time image generation, Interactive image generation. 1. INTRODUCTION An aquarium is one of the most popular educational and entertaining facilities for children and even for grown up people too. But most of existing aquariums display creatures living in relatively shallow waters or beaches. This is partly because the construction of deep sea circumstances costs very high and breeding deep sea creatures are relatively difficult. Then we have considered constructing a deep sea aquarium by computer animation virtually. Using this electronic aquarium, 3 dimensional moving images of deep sea creatures can be observed interactively. As the generated images can be transmitted through communication networks such as internet, the people who want to learn about the behaviors of deep sea creatures can see them from their own remote terminals at any time. Constructing the shapes and behaviors of deep sea creatures based on biological knowledge, the system can also be used as a teaching material for scientific education. 2. SYSTEM DESIGN An electronic aquarium system is composed with an image generation center, networks and remote terminals as shown in Figure 1. Image Generation Networks Remote Center Terminals Figure 1 Electronic aquarium system Image generation center which is the most important facility of an electronic aquarium system is equipped with an image database of deep sea creatures. And it generates deep sea images viewed from front and back windows of a deep sea exploratory submarine virtually. The deep sea creatures generated in our system are Japanese spider crab, nautilus, angler fish, coelacanth, shark and so on. Their shapes are described as 3 dimensional models. And their behaviors are generated and displayed as the combination of motions of several body parts of creatures connected with their joints each other. The submarine can be controlled to move around interactively in 3 dimensional directions, such as back and forth, up and down and left or

2 right turns based on the control signals from remote terminals. Remote terminals are equipped with image displays, data input and data transmission control devices. Through the remote terminals, observers can drive the exploratory submarine and get the deep sea images. 3. IMAGE GENERATION AND DISPLAY FUNCTIONS The image generation center of an electronic aquarium system has the following functions. (1) Image generation of deep sea creatures (2) Motion generation of deep sea creatures (3) Generation of rear mirror images (4) Displaying the name of deep sea creatures (5) Motion generation of a deep sea exploratory submarine (6) Generation of a submarine compass (7) Generation of depth meter 3.1 Image generation of deep sea creatures The images of deep sea creatures are described as 3 dimensional models. The bodies of the creatures are divided into several motion units such as a head, front and rear bodies, tails, fins and so on, connected with each other by their joints. The shapes of creatures are depicted manually using 3D modeling software. Color textures of creatures are generated by texture mapping technique onto the 3D models using 2 dimensional photos of deep sea creatures (Figure 2). 3.2 Motion generation of deep sea creatures The motions of deep sea creatures are generated by key frame techniques of modeling software. Deep sea creatures vary their shapes in accordance with their own swimming forms. Then, we firstly extract a several number of typical swimming forms (key frames) and secondly interpolate them continuously. Deep sea creatures also move and swim with their own (a) Texture of coelacanth (b) Texture mapped image of coelacanth Figure 2 Texture mapping of coelacanth speeds. Swimming speed and loci of creatures are determined by biological knowledge. 3.3 Generation of rear mirror images Our deep sea exploratory submarine has two windows (a front window and a rear window). The image in a rear window is displayed as a mirror image of creatures in a backward. The mirror images can be generated by inverse scanning of model object image (Figure 3). (a) Mega mouth in backward (b) Mirror image of rear window Figure 3 Generation of rear mirror image

3 3.4 Displaying the name of deep sea creatures The names of deep sea creatures are displayed in a display window. In our system, name tags and flashing arrows pointing the creatures are displayed in a front window (Figure 4). Figure 4 A name tag and a pointing arrow 3.5 Motion generation of deep sea exploratory submarine The deep sea exploratory submarine can move up and down, back and forth, left and right turns based on the control signals from remote terminals. In accordance with these motions, the shift images, the zoom in or out images and panning images are generated by image processing techniques. 3.6 Generation of a submarine compass In order to display the posture of submarine and the locations of deep sea creatures, we provide a submarine compass which shows the direction of submarine and 2 dimensional positions of deep sea creatures around the submarine (Figure 5). In Figure 5, deep sea creatures are displayed as pink dots. Observers can indicate the direction of submarine and drive it through remote terminals. In accordance with the direction of submarine, the submarine compass rotates. 3.7 Generation of a depth meter We can calculate the depth of submarine from a sea level virtually and display them in a front window. Also in this case, observers can indicate the depth of submarine through remote terminals. In accordance with the depth of submarine, the deep sea images are shift up or down and displayed. 4. SYSTEM GENERATION FACILITIES Image generation tools of our system are listed below. 3D modeling soft: Light Wave 3D, Display soft: DirectX 3D, Programming language: C++, Operating system:windows, Program compiler: Visual Studio.net, Processor: Desk top computer. With this set of software, deep sea images viewed from submarine can be generated in real time and displayed interactively. 5. GENARAL FLOW OF IMAGE GENERATION Figure 6 shows the general flow of image generations of our system. 3D modeling of creatures Texture mapping of creatures Motion generation of creatures Installment of interactive functions Displaying generated images Figure 5 Submarine compass Figure 6 General flow of image generation

4 Prior to the image generation process shown in Figure 6, we provided the image information about deep sea creatures such as their formal names, shapes and photo textures. 6. SOFT WARE CONFIGURATION Figure 7 shows the soft ware configuration of our system. Programs are constructed by Visual Studio.net. Figure 8 3D modeling by Light Wave 3D Figure 9 shows the generated images of deep sea creatures. (a) Nautilus (b) Oarfish Figure 7 Soft ware configurations 7. GENERATION OF DEEP SEA CREATURES Every deep sea creature has been modeled by modeling soft interactively. In this process, proper joints are embedded in a model object for its motion generation (Figure 8). Motions of creatures are generated by indicating their positions along the time table. Smooth motions are generated by interpolation technology of 3D modeling software with the use of key frames. The motions of all creatures are displayed simultaneously and independently in real time. (c)atlantic footballfish (d)japanese spider crab (e)megamouth shark (f)megalaodicopia hians (g) Pelican eel (h) Coelacanth Figure 9 Generated deep sea creatures

5 8. GENERATED FRONT WINDOW IMAGE Figure 10 shows a generated front window image of our exploratory deep sea submarine. Figure 10 Deep sea creatures A rectangle window displayed on the upper side of Figure 10 shows a backward mirror of submarine. A circle displayed on the upper right corner shows the submarine compass. The number displayed at the left side bottom is the depth meter of the submarine. 9. CONCLUSION As one of promising applications of Virtual Reality, we have constructed a sea aquarium for deep sea creatures. And interactive and real time motion generations of deep sea creatures have been attained. As all these images are generated electrically, they can be transmitted through communication networks such as internet. Therefore this system indicates a possibility of a future network museum. And furthermore, composing the shapes and motions of deep sea creatures based on the scientific knowledge, this system can be used as an effective educational facility. REFERENCES [1] " X. Tu, D. Terzopoulos, Artificial fishes: Physics, locomotion, perception, behavior," Proc. ACM SIGGRAPH'94 Conference, Orlando, FL, July, 1994, in Computer Graphics Proceedings, Annual Conference Series, 1994, [2] Demetri Terzopoulos, et.al, Artificial Fishes: Autonomous Locomotion, Perception, Behavior and Learning in a Simulated Physical World, Artificial Life, 1(4): , 1994 [3] x/default.mspx [4]