Elements Attempted

• Multi Ropes: 3D ropes interact with the floor and the obstacle in a very natural way

• Cloth Simulation: Other than basic implementation and tuning parameters, I also implemented an effective contact detection method using the class activity code as basis, and added a friction term so that the interaction between the object and the cloth is more natural. Furthermore, I implemented user controlled wind to the simulation. The cloth behaves naturally in the wind.

• Air Drag for Cloth: I implemented the air drag term using a quad surface defined by the two cross vector of 4 adjacent nodes. The result is good.

• 3D Implementation & Rendering: Both my ropes implementation and cloth implementation are in 3D, with the camera class.

• User Interaction: User can control the obstacle ball's position, reset system, and generate wind

• Realistic Speed: I don't have a flag to check what real speed compares to my simulation. Visually it seems to be close enough.

• Ripping/Tearing: I was able to render a torn flag.

• Continuum Water Simulation: I implemented a 1D shallow water simulation based on the lecture. Different boundary implementation results in different simulation effects. I make it so that user can change boundary implementation and reset the system to check results.

Team Member

• Hailin Archer deak0007@umn.edu

Codes

https://github.com/CyberHolmes/CSCI5611/tree/master/Project2

User Interaction Controls

3D Camera Control (All 3D simulations):

• 'w': positiveMovement.z

• 's': negativeMovement.z

• 'a': negativeMovement.x

• 'd': positiveMovement.x

• 'q': positiveMovement.y

• 'e': negativeMovement.y

• LEFT: negativeTurn.x

• RIGHT: positiveTurn.x

• UP: positiveTurn.y

• DOWN: negativeTurn.y

Obstacle Ball Control (Ropes, Cloth):

• j : x axis negative move (left)

• l : x axis positive move (right)

• i : y axis negative move (up)

• k : y axis negative move (down)

• u : z axis negative move (in)

• o : z axis negative move (out)

Wind Control (Ropes, Cloth):

• b: continuous pressing turns on the wind, release the key to turn off the wind

System Reset to Initial State (flag position, ropes position, water level) (All Simulations):

• r key: press once

Change Boundary Implementation In Water Simulation:

• key '1': periodic

• key '2': free

• key '3': reflective

Multi Ropes In 3D

Description

Extended the rope implementation shown in class to support multiple independent ropes which all hang and swing freely. The ropes interact with a floor by falling naturally on the the floor. The ropes also interacts with a large moving ball which user controls. Ropes have a smooth, natural looking swinging behavior.

User can use the following keys to control the obstacle ball:

• j : x axis negative move (left)

• l : x axis positive move (right)

• i : y axis negative move (up)

• k : y axis negative move (down)

• u : z axis negative move (in)

• o : z axis negative move (out)

User can turn on the wind by continuously pressing 'b' key.

User can reset the system by pressing 'r' key.

Code

https://github.com/CyberHolmes/CSCI5611/tree/master/Project2/MultiRope_v0

Video

Cloth Simulation

Description

Implemented a cloth simulation in 3D. Rendered the cloth as an American Flag. The cloth supports one-way interaction with a large ball which can be moved around in the 3D space by users. The cloth falls naturally on the ball and moves naturally with the ball. I also implemented wind which user can turn on and off. User can view the scene from different angle by controlling the camera (implemented with the camera class provided in class)

Code

https://github.com/CyberHolmes/CSCI5611/tree/master/Project2/Cloth3D_Checkin

Video

Air Drag For Cloth

I implemented the air drag term discussed in the class video. I used a quad surface formed by four nodes to calculate the drag force, then divided the force by 4 and applied this force to all four nodes.

Cloth Implementation: More Sophisticated Contact Detection

I implemented detection using lines formed between nodes, on top of nodes contact detection.

Additional friction term for obstacle contact

I added a friction term for the contact handling, so that cloth does not slip off the object unnaturally.

Ripping/Tearing Implementation

I implemented a torn cloth. It interacts with an obstacle as a torn cloth would.

Code

https://github.com/CyberHolmes/CSCI5611/tree/master/Project2/ClothWithTear3D_Checkin

Continuum Water Simulation

Description

In this 1D shallow water simulation, the water starts with a inverse log profile where the level is high on the left. User can switch boundary condition by pressing key '1', '2' and '3'. User can also reset the water level to the initial state by pressing 'r' key.

Code

https://github.com/CyberHolmes/CSCI5611/tree/master/Project2/MySWE_1D_v0

Tools/Libraries Used

• The hitInfo class from CSCI5611 class live activites session

• The 3D Camera class provided in class

• java.util, javafx.util

Other Resources Used

• processing.org: processing programming reference, general language tutorial

• https://pixabay.com/: The American Flag image

Difficulties Encountered:

• Rendering a cloth tear turns out to be very difficult. I was only able to render a straight cut. I am not sure how to render a natural looking tear at this point.

• Making a torn cloth look natural is difficult. All the parameters that worked when the cloth is whole does not work the same when the cloth is torn. Interaction with the obstacle also changed at the torn part.

• Making contact detection work right took me a long time.

• I attempted to implement a separate set of spring and damping between every other row/column nodes in cloth simulation. It made the simulation worse.

• The water simulation can accumulate error with 'free' and 'reflective' boundary conditions, resulting in total volume change. I needed to implement a volume normalization routine so that the total volume does not change.

• Rendering a nice backdrop is very costly, resulting in low frameRate. I couldn't use the Mount Rushmore background because the framerate would drop from 50+ to below 30. This may not be an issue if I have a more powerful computer. My system is an HP envy laptop.

Art Contest