## Tutorial 02: Getting Even More Started with Houdini

In the previous tutorial, we learned a lot of technical details on how to use Houdini. In this tutorial, we will go into more depth and learn how to write code on geometry. Will this be fun? Why would anyone ask that? Of course!

## Tutorial 01: Getting Started with Houdini

Let us get started with Houdini!

I will do my very best to make your entry as smooth as possible. It will be like sitting in a cockpit with the fear of crashing the plane by hitting the wrong button but rest assured that we will bit by bit learn to understand the software. It will be worth it and you will get a nice insight behind the scenes of Hollywood production on the way.

## Lecture Progress

• Week 1: lectures only ( October 16 – 17 )
• Planar curves. Parametrizations, geometric quantities, length variation, turning angles. Discrete planar curves. Discrete arc length, curvature.
• Discrete space curves. Frames. Frenet-Serrat formula. Smooth surfaces. Metric. Curvature.
• Lecture notes
• Week 3: tutorials only ( October 30 – 31 )
• Houdini Workflow, lights, camera, rendering.
• Working on common examples.
• Week 7: lecture and tutorial ( November 27 – 28 )
• Discrete Exterior Calculus, Take Two: the dual complex. See also paragraphs 1-6 and 9 from this publication on DEC by Desbrun et al.
• An example of the complications in building exterior derivative operators in the presence of boundaries. Using circumcentric subdivision one can identify ‘dual edges’ with ’90 deg. rotated edges’ and build a ‘boundary operator for dual 2d-cells’ $\partial_2^*$ as the transpose of the primal boundary operator for edges $\partial_1$, with the following relation $\partial_2^*=-\partial_1$. However such a relation cannot be set up for $\partial_1^*$  since one would need to add the midpoints of the boundary edges as vertices, and the sizes of $\partial_1^*$ and $\partial _2^T$ would no longer match.
• Week 8: lectures only ( December 4 – 5 )
• Whitney Elements.
• Differential Equations on Manifolds. Physical Units.
• The Heat Equation – Derivation and properties of the solution.
• Finite Elements: Weak and Strong formulations of the heat equation.
• Week 9: lectures only ( December 11 – 12 )
• Discrete Finite Elements. Time Discretization/Stability. Poisson equation.
• Conformal maps.
• Week 11: lectures and tutorial ( January 8 – 9 )
• Week 12: No lectures ( January 15 – 16 )
• Week 13: No lectures ( January 22 – 23 )
• Week 14: lectures only ( January 29 – 30 )
• Week 15: Tutorials only ( February 5 – 6 )
• Boundary conditions: Dirichlet and Neumann
• Week 16: Tutorial and Project presentation ( February 12 – 13 )

The Software used for the Homeworks is called Houdini from SideFx. Upon signing up and installing you will be able to use the free version (apprentice) which comes with no drawbacks accept render resolution caps and watermarks.

We recommend installing the 16.5 version of Houdini. This is due to issues with the use of the Python package Scipy in the newest versions. Please head over to this daily build site to install the 16.5 version.

Why Houdini? It is the leading VFX tool and has, has a nice GUI and comes with a lot of tools and has nice rendering.

Here are some of our previous projects done with Houdini.

Other people:

More cool stuff because of SIGGRAPH

## Welcome!

This is the course blog for the TU Berlin course in the winter semester 2019/2020.

Course Times
Wed. 12-14 MA 749
Thu. 12-14 MA 645

Contact
Olga Diamanti – diamanti_at_math.tu-berlin.de

Office Hours
Thursdays 14:00-16:00 at MA 823.

New posts will arrive below this sticky post. Please stay up to date with the announcements on this post. There may be changes to the schedule during the course and they will be posted here.

Announcements

• 11.03.2022: New download folder link for all the files! (There was an issue with the cloud service.)
• 30.01.2020: All the notes for the course material have been posted either in the downloads folder or as links in the course progress post.
• 30.01.2020: The final project topics are now online. Click this page for further information.
• 09.01.2020: Practical Implementation Homework 05 is now online. Click here to flatten. (Due Tuesday, January 28.)
• 20.12.2019: Some candidate papers for the implementation project have been (tentatively!) posted. See the downloads folder.
• 20.12.2019: Pen & Paper Assignment IV has been posted.
• 19.12.2019: Practical Implementation Homework 04 is now online. Click here to splish splash.
• 04.12.2019: Pen & Paper Assignment III has been posted.
• 28.11.2019: Practical Implementation Homework 03 is now online. Click here and burn the bunny.
• 20.11.2019: Practical Implementation Homework ist now online. Get creative and click here.
• 15.11.2019: Pen & Paper Assignment II has been posted.
• 07.11.2019: The first practical implementation homework is now online! Click here.
• 24.10.2019: Pen & Paper Assignment I has been posted. In preparation for next week’s Houdini tutorials, please install Houdini as described here.