Advanced Rendering Module

This project was carried out as the practical work part of the Advanced Rendering module taught during the second year of my engineering studies at ESIR. It was a pair project on which I worked on with Kelig Perigault. This project was structured in three parts: the first was to create and animate an object using a scene graph, the second was to implement an inverse kinematics algorithm to control an articulated arm, and the final part was to build a spring-mass system to simulate the movements of a patch of fabric.

Scene Graph and First Animations

This part consisted of creating a butterfly-like “insect” using the scene graph, then animating it to simulate a wing flapping. Next, we were tasked to animate its movement by making it follow a trajectory by developing and using a cubic Hermite spline interpolator, while correctly adjusting its speed and orientation in relation to its current trajectory.

Watch the video below for a demonstration of this “flying insect” animation.

Inverse Kinematic

For this part we created a poly-articulated chain that we added to the scene graph. This chain is represented by a series of cylinders of 0.1 radius and 0.5 height connected by joints represented by spheres of radius 0.2. Each joint has one rotation along its local X axis and one rotation along its local Z axis, i. e. two degrees of freedom. Then we implemented the cyclic coordinate descent algorithm to solve the inverse kinematic equation, in order to be able to point the end of our poly-articulated chain towards a point in 3D space. The result of the calculation is displayed at each iteration of the algorithm until it converges.

Watch the video below for a demonstration of the inverse kinematic implementation applied to a five segment long fixed arm with four articulations allowing two degrees of freedom.

Spring-Mass System

For this project we had to create and configure a simulation system to calculate the positions of a spring-mass system according to the different forces and constraints it is being subjected to. In this system, we modeled the force of gravity, the binding force of the springs and a damping force to stabilize the system. We also added the ability to specify constraints to masses in order to anchor their position in space or to simulate a collision with another geometry. This physical simulation system is updated at each iteration of the program’s main loop and the results it provides are applied to a corresponding visual representation in the scene graph, namely a mesh whose vertices are displaced.

Watch the video below for a demonstration of this spring-mass system simulating a cloth being dropped on a sphere with its four extremities released successively.