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Tutorials LightWave 3D Copter: An Introduction to Expressions Qua Jan 26, 2011 2:40 am
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| by Richard Brak |
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| Intro | Part I | Part II | Part III | Part IV | Part V | Part VI | Part VII | Downloads Introduction This tutorial is an introduction to the use of LightWave 3D's expressions to rig mechanical systems. I assume very little mathematical or expression knowledge, but I do assume you have a little working knowledge of the rest of LightWave®. The tutorial uses an imaginary pedal powered helicopter to illustrate the use of expressions in a few simple contexts. Since the emphasis of this tutorial is on the use of expressions to rig mechanical systems, I have provided all the objects and scene file (I will have little to say about the modelling of the Copter) – see the download page.  The tutorial is broken into several parts. At the beginning of each part the complete scene file up to that stage is provided. Thus you can skip any part, load the scene file at the beginning of that part and do only that part of the tutorial. <table cellpadding="5" cellspacing="0" width="100%"> <tr> <td valign="top" width="11%">  </td><td valign="top" width="89%"> Part I: A general introduction LightWave® Expressions. This part is somewhat brief (and not intended as a replacement to the manual). You can skim through this part at first reading and return later as needs be. </td> </tr> <tr> <td valign="top" width="11%">  </td><td valign="top" width="89%"> Part II: Null rigging of the model. The use of Nulls is very important in any mechanical rig, thus in this part we load the objects and parent them to appropriate Nulls. </td> </tr> <tr> <td valign="top" width="11%">  </td><td valign="top" width="89%"> Part III: The pedals. This Copter is pedal powered. The rotation of the pedal gear will be under the animators control with keyframes, but, using expressions, we will make sure the pedals automatically point in the same direction (irrespective of the rotation of the gear). </td> </tr> <tr> <td valign="top" width="11%">  </td><td valign="top" width="89%"> Part IV: The chain. The rotation of the chain connecting the pedals to the rotor can be set up in several ways. We will use the morph method with an expression controlling the morph percentage to ensure the chain rotation is synchronised to the gear rotation. </td> </tr> <tr> <td valign="top" width="11%">  </td><td valign="top" width="89%"> Part V: Rotor, counter rotor and associated gears. In this part we set up expressions to link the rotation of the rotor to the pedals and chain. </td> </tr> <tr> <td valign="top" width="11%">  </td><td valign="top" width="89%"> Part VI: Rotor Droop. To add some realism to the motion we use use an EndoMorph rotor object and expressions to control the "droop" of the Copter rotor blades. The new ingredient in this part (cf. part IV) is that we want the droop to be controlled by the speed of rotation (not the amount of rotation). </td> </tr> <tr> <td valign="top" width="11%">  </td><td valign="top" width="89%"> Part VII: The Wheels. Finally, we add rotation to the wheels. In this part conditional (or control) expressions are introduced to ensure the wheels only rotate when the Copter is on the ground, but respond to keyframing when the Copter is off the ground. </td> </tr> </table> I hope this tutorial flattens the learning curve a little. Drop me an email (r.brak@richardbrak.net) if you have any queries or comments. Cheers, Richard Brak. PS. Almost all the images can be clicked on for higher resolution versions (in a separate window – which closes automatically, or, if you prefer, clicking on the target,  ,which will open the image in the same window). All contents copyright © 2001 Richard Brak unless otherwise specified. All the objects and scenes are copyright. They may only be used as part of this tutorial and for no other purpose whatsoever unless my permission is first obtained. |
