Learning Houdini Journal 12: Fine Tuning the Car Impact

Staff Writer By: Ricky Grove (gToon)

Learning Houdini Journal 12: Fine Tuning the Car Impact | Learning Houdini, Houdini, modeling, tutorial

This is the twelfth entry of what will be a year-long journal on learning the 3D application Houdini, created by Side Effects Software. Houdini is a sophisticated application that is widely used in the production of visual effects for Hollywood films such as Big Hero 6, Mad Max: Fury Road and many others.

In my previous Learning Houdini Journal 11, I discussed learning about bounce, friction and velocity as it pertains to dynamics animation inside of Houdini 15. In this journal entry, I'm taking this further and applying what I've learned to making the race car crash (from the Introduction to Houdini 15 tutorial I'm working my way through) more realistic by fine-tuning the animation.

Fine-Tuning the Ground Plane and Race Car's Parameters
It was relatively easy to get the race car in position and then create the ground plane for the city set that the pluralsight.com Intro course provides. Once in place, it was a matter of making the car a dynamic object and the plane a static object.

Now it's time to experiment with degrees of velocity, friction and bounce to make the race car's crash through the window, arc through the air and then impact with the street below. All of the adjustments are general at first then more specific as I play back the animation to see the results. It all seems a bit clunky as it would be much simpler to make the adjustments inside the scene rather than in the parameters area. But this is nit-picking as the changes are quick and the animation is easy to reset.

Working with the instructor, John Moncrief, I adjusted the initial velocity to give a greater sense of push out of the window. After that I spent the most time getting the friction right for the ground plane as the increments had to be almost in the .001 amounts to get the right look. Angular velocity was adjusted as well in the Y and Z planes to get the car to move towards where the main camera would be.

adjusting the velocity of the race car

The Bounce Issue
The only real problem I had in adjusting dynamics parameters was with bounce. Somehow, even using the exact same amounts that the instructor was using, I got a slightly different result. I'm not sure why that is as I'm using the scene the instructor provided and not my own version of the scene. I suspect there's some small adjustment I've made somewhere that varies the results slightly. In any event, I was able to get the bounce to a point that I thought gave more realism to the cars impact with the ground.

The adjustments I've made make the car's dynamic animation more realistic, although I'm certainly not satisfied. I think I've got to get the car's rear end to come down some as it's arcing in the air. Then the rear wheels hit first. This will take some more minute adjustments, but it's getting there.

Quick Recommendation
Even though my focus is on the Introduction to Houdini 15 course, practically every day I spend time hunting down leads on tutorials, news and info via my daily Google search results. I came across an interesting one this last on Vimeo.com. It's by Simon Holmedal and it's called, "LAB: Cinema 4D vs Houdini". Simon is a whiz at both programs and wanted to work his way through the pros and cons of working with both programs. I've now subscribed to Simon's channel on Vimeo as he's a smart guy who is able to make complex 3D easier to understand.

Here's the embed of the video:

LAB: Cinema4D vs Houdini from Simon Holmedal on Vimeo.

Next: Creating the Shattering Glass Window