1. On Effective Object Manipulation in Virtual Environments making scene design easier

2. Introduction Problems we are facing Simplification methods currently in use Methods of semantic snapping and automated scene generation

3. In the beginning…

4. However, people always want more.

5. Problems we are facing Simple scenes are unrealistic To achieve realism, we need to design scenes that are much more complex Computing power grows rapidly Designer power stays limited

6. Evolution of design in video games

7. Problems we are facing Scenes that took 2 man-days to lay out fifteen years ago may now require one man-month or more to satisfy the viewers Simplification methods are a must – we need to introduce methods for effective object manipulation

8. Freedom of motion When moving an object around in 3D space, we have 6 degrees of freedom:

9. Restricting the movement Having all six degrees of freedom complicates precise manipulation We need to use some constraints to restrict the object movement One of the few options of restricting object movement in today’s editors is snapping

10. Basic snapping Ordinary snap tools utilize a grid of regularly-placed points to snap to Basic snapping makes design more precise… …but not faster… …because all parts of the scene are equivalent in terms of snapping

11. Advanced snapping Advanced techniques attach objects to other scene objects instead of pre-defined set of points Given no semantic information, the system still cannot determine the most appropriate object placement This can lead to some unpredicted and undesired consequences

12. Adding semantics We will provide the system with information on where each object belongs e. g.“desks usually stand on the floor”, “a chair goes in front of a desk” With a capable solver, the problem of placing an object into an appropriate position is thus reduced to moving it only roughly into the desired place

13. Adding semantics The constraints may be represented using two sets of polygons for each object Offer areas Binding areas The job of the solver is to take the object being moved and align its binding areas with nearby offer areas

14. Adding semantics Once two objects are properly aligned, they enter a parent-child relationship When the connected objects are “torn” apart, this relationship is cancelled This allows for dynamic forming of groups without the user even noticing By moving the parent of a group, the user can move the whole group

15. Advantages of semantic snapping We can specify which areas may or may not be connected by creating a semantic hierarchy By carefully choosing binding and offer areas, we may prevent some object interpenetrations even without full-scale collision detection We may even have the solver lay out the scene automatically

17. Thank you for your attention