1. Levelsets in Production : Spider-Man 3

2. What are levelsets? Implicit surface representation
SDF (signed distance function) in a regularly sampled grid.

3. Sandstorm Rich toolset
Includes levelset-based modeling and animation tools.
Geometry to Field
Field to Geometry
Field Attribute transfer / lookup
Snap to levelset
etc

4. Benefits of Levelsets Distance to the surface Inside or Outside
Boolean operations
Surface modification (noise)‏
etc

5. Examples :
Combining two fields

6. Examples :
boolean union - max(A,B)‏
intersection - min(A,B)‏

7. Examples :
boolean cut - max(A,-B)‏
adding noise to the result

8. Procedural noise variations
Examples :
Procedural noise variations

9. Case 1 :: Geometry Blending
Create two identical fields
Convert geometry into levelsets
detect the places where the two objects intersect in the field with a certain threshold

10. Case 1 :: Geometry Blending
Calculate the resultant levelset with:

12. Case 2 :: Erosion Work in a still frame
Distribute particles uniformly in the geometry
Particles will store the erosion amount
Convert the geometry into a levelset
Modify the levelset (amount attibute + spatial noise)‏
Apply the erosion to the moving geometry

13. Erosion - Examples

14. Case 2 :: Erosion
Primitives will be triggered when containing particles with a positive erosion value
Non-triggered primitives will generate the sand particles in render time.

16. Erosion - Examples

18. Case 3 :: Particle trajectory correction
Geometry Normal is stored in the levelset
Normal component is passed to the particle
Particle velocity vector is updated every frame using the levelset normal component to avoid penetrations.

19. Case 3 :: Particle trajectory correction

21. Examples : Forming Shape

23. Case 4 :: Levelset Collision
Uses levelset for collision detection
Fast
Positive field(Φ>0) ⇔ Inside geometry
Robust
Closed & Non-intersecting
w/o multi sampling
Obviously we simulated tons of particles, and having robust collision detection was very important for sand effects.

27. Case 5 :: Polygonization
Compute Normal and Curvature for Instancer tool

31. Thank you!