Chapter 12.0 Vehicles: Importing and Rigging

A vehicle in Unreal is any physical object used by the player to get around the world. The first things that may come to mind are wheeled vehicles like cars and trucks or flying vehicles like planes and helicopters. However, the vehicle system and rigid body physics engine in Unreal allow for great flexibility in the types of vehicles that can be created. Anything from those cars, trucks, planes, and helicopters to tanks or other vehicles which use treads to hovering vehicles like a hovercraft or hoverboard to biological vehicles such as horses to mechanized walking vehicles is possible using this system. This means that not only is it possible to create games which use vehicle combat, but the system could also be used to create horses that can be ridden for a horse racing game or a western. The vehicle system could even be used to create surfboards or snowboards for simulations. Of course, with more specialized types of vehicles it may become necessary to implement custom functionality, but the framework and overall system is in place to allow you to simply add what is needed for a specific type, and not have to build the entire system from the ground up.

Setting Up Vehicles
Vehicles in UnrealEngine 3 use a skeletal mesh to render. This makes it easy to import a mesh with multiple moving parts for wheels, suspension, flaps, doors etc as one asset. Vehicles can take many different forms - but the code does assume they have a single rigid chassis. If your vehicle has wheels, you can use any number you like, and they can be of different sizes. any more than four wheels will require additional programming.

SVehicle Creation
This document will go over what you need to know to create your own SVehicle. It will cover from modeling the vehicle to putting it in the engine. Included in this document are example vehicles in both Maya and 3D Studio MAX. This document also includes a .UKX animation package and map with these vehicles in the game. This document does not go over how to tune vehicles or how to create completely new types of SVehicles. See the SVehicleReference for information in that vain.

SVehicles are a different type of Karma vehicle than KVehicles. The main difference between SVehicles and KVehicles is that SVehicles are made of skeletal meshes as opposed to static meshes. You access SVehicles from the "Animations" browser and you export SVehicles from the modeling program with ActorX. Because the meshes have skeletons, SVehicles can include things like tires and moving gun turrets in the single mesh for the vehicle. Previously, with KVehicles, any moving part has to be a separate mesh and a separate object. SVehicles can be made in both Maya and 3D Studio MAX though the creation process is very different for each. Maya uses bones to control the different parts of the mesh. This is very similar to the normal animated skeletal mesh creation for Unreal. MAX on the other hand does not use any bones, despite the fact that this is a skeletal mesh. Object hierarchy in MAX can be used to generate a skeleton in Unreal. The different parts of the mesh are actually different objects in MAX all "linked" to the root object.

Once created, unlike all other skeletal meshes for Unreal, SVehicles are not animated. The only thing that is important is the mesh/refpose; this is the only thing you should export from the modeling program and the only thing you should import into UnrealEd. Once in Unrealed, SVehicles are not linked to any existing animation.

**Topics to Explore**
  • Maya Rigging Fundamentals

No comments:

Post a Comment