International Conference on Control, Automation and Systems 2008
Oct. 14-17, 2008 in COEX, Seoul, Korea
Interactive level of detail control for film quality crowd animation
Sung June Chang
指導老師 陳炳彰
報告學生 鄭惠云 M99F0212
INTRODUCTION
In the field of film quality animation, the designer usually finalizes key
frame animation to make the reality, but the massive crowd animation is not
possible to change every animation key because it needs huge time and
memory.
So the overall crowd formation is generated by computer simulation
and then is divided into the small piece of scene to be easily controlled by
the designer.
Firstly,the divided scene is the just part of total crowd, which is not
enough for the designer to view the overall crowd movement.
Secondly, the key frame change in the divided scenes can cause the
problems in rejoining them to make the final result because the change in
the divided scene can cause side effects to the other divided scene.
But it is not easy to simulate to compensate the side effect after
simulating each divided scene.
INTRODUCTION 2
Instead, our approach uses interactive LOD control to solve the
cooperation of computer simulation and designer.
After computer simulation, the designers can use the total crowd
simulation result without dividing into scenes.
The designer can control the time and memory to use the simulation
result by interactively changing each LOD.
If they want to view the total movement easily, then change LOD to
more simple level.
And they can view the detailed key frame by interactively changing LOD
of the dedicated agent in the same scene.
So they can retouch each agent’s key frame while viewing total agent’s
movement.
In this paper, the first part explains interactive LOD control, which is
divided into the introduction of three different detail levels of LOD, high level
software structure and block diagram style’s algorithm.
And the second part shows how to use interactive LOD control in our
film making pipeline.
Detail Level
3 kinds of detail level.
- Locator level
- Hexahedron level
- Real model level
Fig. 1 Detail Level
(Locator, Hexahedron, Real model)
Fig. 2 Software date structure
Fig. 3 Algorithm of interactive LOD
Pipeline
Our crowd animation pipeline consists of base work, design work, and
simulation work.
In base work, we collect crowd motion by motion capture and film
quality texture model by various texture maps, and then make crowd
formation in computer simulation work.
Lastly, we finalize animation key in the result of simulation by design
work to make the reality of each agent’s motion which is near the camera
view because the error of motion is observed easily in close shot.
Application
The problem of general film quality’s crowd animation pipeline is the
cooperation of computer simulation and designer’s post processing which is
necessary to make film quality animation.
Animation editing by designer necessarily needs to show the real look
model but we cannot display many real look agents in one scene because of
heavy time and memory usage of the real model.
So we adapt the interactive LOD control.
We select the locator and hexahedron level of detail in extra agents to
show overall crowd formation change without time and memory problem,
and at the same time we select the real model level in the leading agents
whose animation needs to be edited by the designer.
Application 2
In the application, we adapt real model view and hexahedron view at
the same time.
For default view, we use hexahedron view because it shows the volume
but it is not heavy.
And we change view agents in the bottom of Fig. 4 by selecting each
agent and changing its view into real model view to see the real motion.
So we can observe both real motion of agents and total crowd
formation at the same time.
And when we want to change key animation of one agent, we need to
change others view into locator view because changing key needs to
minimize display time which is consist of displaying other agents.
Fig. 4 Application of LOD
Conclusion
This paper proposes interactive LOD control for film quality crowd
animation.
In the field of film quality animation, the designer
Firstly, we show our 3 different LOD view which consist of locator view,
hexahedron view, and real model view, its 2 layer software structure which
consist of management layer and realization layer, and its algorithm.
Secondly, application of interactive LOD control in real film making is
explained.
We suggest how to change the pipeline of crowd animation in film
making, and explain our application of crowd animation in film making.
Conclusion
Our method successfully shows overall crowd movement and detail
motion of selected character at the same time.
So designers can easily finalize key frame animation in the close shot
considering overall crowd.
We want to improve our algorithm in many points.
We plan to automate view change process. For example, view can be
changed according to the distance of camera.
Various kinds of LOD are also needed.
And automatic converting from normal scene into interactive LOD is
necessary.
End