The document introduces Park Min-geun, a game developer who has worked on projects such as Dragon Ball Online and PlayNC billing servers. It then provides a detailed overview of how to implement ragdoll physics in games like Diablo 3, including the content pipeline to author ragdolls, exporting ragdoll data, using a game editor to test and tune parameters, and spawning ragdolls in the game world.

2. 강연자 소개
박민근 (@agebreak)
네오위즈 게임즈 (야구의 신 개발중)
NTL-inc - 드래곤볼 온라인 개발
엔씨소프트 – PlayNC 빌링 서버 개발
(http://agebreak.blog.me)
(cafe.naver.com/devrookie)

3. Diablo 3 Ragdolls
How to smack a demon
Erin Catto

4. I wanted to give Diablo the most
awesome ragdolls ever!

5. Ragdolls in 3 steps
1. Content pipeline
2. Animation pipeline
3. Tuning

6. We need a content pipeline to author
and tune ragdolls
Artist Tool Game Editor

7. A ragdoll is a collection of collision
shapes connected to bones

9. Physics joints connect two bones
Cone Joint Revolute Joint
Spherical Joint Weld Joint

10. The ragdoll data is exported with the
model
Maya export Intermediate File
(Maya Plug-in)

11. Ragdoll data is imported by the game
editor (called Axe)
Intermediate File cook Run-time File
(Axe Game Editor)

12. Bones are sorted in parent-child order
struct Bone
{
int parent;
int child;
int sibling;
};
#define NULL_BONE (-1)

13. Here’s how we compute model space
bone transforms
// MS: model space
// PS: parent space
for (int i = 0; i < boneCount; ++i)
{
int parent = bones[i].parent;
if (parent != NULL_BONE)
transformMS[i] = transformMS[parent] * transformPS[i];
else
transformMS[i] = transformPS[i];
}

14. Bones with bodies are active, the rest
are leaf or intermediate bones
#define LEAF (-1)
#define INTERMEDIATE (-2)
int boneToBodyMap[BONE_COUNT];

15. Building the bone to body map

16. Ragdolls are tested and tuned in
the Axe game editor

18. The model viewer has a mouse
joint

20. Parameters and collision flags can
be tuned

21. Animation triggers create ragdoll
events

22. Ragdolls are a form of procedural
animation
Ragdolls
Interpolation
Inverse Cloth
Blending Kinematics
Parent Space World Space

23. We use the ragdoll bodies to adjust
the pose
model space keyed animation world space ragdoll

24. Leaf bones retain their relative pose
keyed animation ragdoll

25. Intermediate bones go to the bind
pose
B in bind pose B in animated pose
 stretching
|A-C| = constant

26. Update the actor bounding sphere
using the bone transforms
actor transform

27. Ragdolls are spawned with care

28. Spawning in-place causes joints to
stretch

29. Obtain the initial velocity from
two world-space bone poses
𝑝2 − 𝑝1
𝑣=
∆𝑡
2 𝑞2 − 𝑞1 𝑞1
𝜔=
∆𝑡
check the polarity!!!

32. Help, my foot is stuck in the floor!

33. Using sequential ray casts to get
unstuck

34. Tune your ragdolls to improve quality

37. Don’t support heavy bodies with small
bodies
failure point

38. Don’t overlap siblings
ackkk!
ouch!

39. Avoid long skinny bodies

42. Ragdoll effects add variety

43. Explosions are physically motivated
radial
linear

44. Explosions account for distance and
facing

49. Gibbing never gets old

55. Partial ragdolls add flavor to living
characters

56. Partial ragdolls are stabilized with
partial teleportation
2
partial transform: 𝑥1𝑎 = 𝑥1 + 𝛼 𝑥2 − 𝑥1
1a
𝑣
𝑥2 − 𝑥1𝑎
velocity command: 𝑣=
∆𝑡
1
𝛼

155. 풀버전 PT 들은 제 블로그에 올라와 있습니다.
(agebreak.blog.me)