1. VIVA Questions and Answers
Hamzah Asyrani Sulaiman, Abdullah Bade, Daut Daman
VIVA Questions and Answers

2. What is the area in which you wish to be examined?
Thank you, I wish to be examined on hierarchical representation of urban simulation area and collision detection area. It is because due to my research of collision detection method using hierarchical representation in virtual environment which is in my case is urban simulation

3. In one sentence, what is your thesis?
My thesis is about new splitting technique of bounding-volume hierarchies that be able to construct faster than spatial median technique and also be able to traverse faster than previous DFS algorithm combined with new traversal algorithm which are suitable for detecting object interference in urban simulation

4. What's original about your work? Where is the novelty?
My work is on produced a new splitting technique, improvement over previous method where it helps researchers to create more balanced level of BVH in order to be used as hierarchical representation in urban simulation.
The technique be able to construct faster and traverse faster than previous technique. I developed my algorithm for the new splitting technique called SOMS.

5. What are the contributions (to knowledge) of your thesis?
My thesis helps researchers to construct BVH with more accurate and faster BVH for collision detection or other method. Based on experiments that has been undergone, SOMS produced good result and can be used in virtual environment.

6. How does your work relate to spatial median?
My work is closely related to this technique as it helps me to improve and study the effectiveness of this technique before I proceeded with my funding or the weakness.

7. What techniques are commonly used?
For collision detection, it has been said that BVH is the most appropriate technique for it. However in BVH, the most common method is by using AABB and OBB with binary type tree of top-down approach (based on my reading).
On top of that, most prefers spatial median splitting method to construct their tree. Their contribution more on the type of BV and the type of tree.

8. How do scientists/philosophers carry out experiments?
Based on my finding and reading, most of them stay with frame per seconds, time to detect collision or time to construct.
At first they will do the testing on basic objects, before proceed with virtual environment. However, most of them just stick with basic objects as it just to test to fundamental theory of their technique.

9. How would your system cope with bigger examples? Does it scale up?
Of course, we have tested in sample urban simulation which is the outcome of this thesis and this research. We currently in development of real urban simulation where it consists lot of buildings more than this thesis ever has. This thesis scope is to meet the expectation of the technique where the success of this technique is to be determined by the result of the testing procedure.

10. How do you know that your algorithm/rules are correct?
By continuously running the testing and make some comparison with the current technique, we make sure that our algorithm has successfully done by conducting 1000 times construction in order to make sure the algorithm stay. We have proved it throughout experiments and make sure the technique is efficient. We also publish a few papers in order to have attention of international researchers.

11. What are the motivations for your research
What are the motivations for your research? Why is the problem you have tackled worth tackling?
To contribute to one of the main contribution of computer graphics – computer games, I felt that it is required for me to get involved in this area where today simulation become much more realistic than previous year. Construct the better technique for use in games help the games and simulation industries become better especially in medical simulation and games.

12. What is the relevance of your contributions?
To other researchers – help to produce better BVH for collision detection – can be used to multiple method – other BVs, etc
To industries – helps by producing better technique for them when developing simulation and computer games/console games.

13. Where did your research-project come from
Where did your research-project come from? How did your research-questions emerge?
To be honest, it is at first of course maybe because of this is why supervisor had given to me. But looking things behind, I realized at the moment I was beginning to conduct the research on this area, the exciting moment come in.
To justify, conducting a research in urban simulation has become very important especially in the requirement to produce realistic and good simulation. So, in order to tackle the problem of producing realistic simulation various research must be done.
One of them is CD, where the area Im concentrate on right now. So, this things has bring my attention to fully concentrate about this research and contribute to this area.

14. What do you do better than them? What do you do worse?
I perform better in splitting system compare to previous technique. However this algorithm also suffers the same problem but I made it less by improving the method of splitting the longest axis of BVH. Hence, it continues to produce more balance tree and more level of BVH compare to previous technique eventhough there is still some heuristic must be used at the end.
But this limitation occurs because of the triangle is actually the same points that been share by many connecting points to create the triangle.

15. Have you solved the field's problem that you claim to have solved?
To my justification, I constructed a faster method to create BVH from first phase in order to be used in hierarchical representation for collision detection. Field problem is not actually solved because lot of problems happened when two things is never be the same high. Accurate and speed. Both is contracting each other. Higher speed does not mean more accurate. Tackle the accuracy problem make the speed slower especially in continuous collision detection where it relatively much more slower that discrete collision detection.

16. Why did you choose to enter the field of Computer Graphics especially on Collision Detection and Virtual Environment area
The reason of I becoming the researcher in Computer Graphics area is because several reasons. First, there is not much researcher in Malaysia that concentrate on the field that I have taken now. Why? Because we still lack of student and programmer who can program computer games, console games, and so on. Compare to another countries especially USA and Canada, they have lot of opportunity there.
Second is because the interest of myself in this field, I change my course from computer engineering to computer graphics is because is still the same basic things but computer graphics is more on visualization without need to use expensive hardware. We can use simulation to create pre-model of real application without any harm.

17. Why did you choose to enter the field of Computer Graphics especially on Collision Detection and Virtual Environment area(2)
Collision detection play major roles in virtual environment, For me who really like to play games in console or PC, Virtual environment make people having a dream in reality without sleep. They can become whatever they want borderless. So, collision detection is a research where we need to know the contact between two or more objects in order to make it realistic. Otherwise, all objects can be penetrated and no realistic things occurred even though the virtual environment itself is just a virtual and not realistic. However, we still need to bring this kind of mechanism of realism to user.

18. Why it is only you be able to solve the problem and not others?
The reason is quite simple, most of the technique has been developed by well-known researchers all around the world – no doubt they improved a lot in BVs that they have been used, type of BVHs that they have been used, the collision detection technique itself and much more. However, all trying to tackle the problem that already been surface since the past few decades. It is on their mind what they are trying to solve and some ideas just come cross after throughout reading countless time. For me it something that I discovered that splitting technique also can play important role here. That is why I concentrate on splitting and at the end I noticed there is some improvement that can be done for collision detection.
TO be honest, why Mercedes and BMW is two different cars?Why not only only car in this world? Are they tackling the same problems? Both has it weaknesses and so am I.