USARSim Tutorial

1. 1 USARSim Tutorial

2. 2 Outline Building Arena Introduction Components, Unreal Editor and the workflow Static mesh Special effects, victim and light Building Robot Introduction The robot model and procedure Construct the robot Example Summary This session introduces how to simulate arenas and robots. For arena building, we at first introduce the components of arenas, unreal editor and the workflow of building arena in unreal editor. Then we introduce how to build static meshes that construct the arena and other issues like special effects, victim and light. For robot building, we introduce the robot model and the procedure of building robot. Then I explain the details about constructing the robot. And at last, an example of robot will be presented.This session introduces how to simulate arenas and robots. For arena building, we at first introduce the components of arenas, unreal editor and the workflow of building arena in unreal editor. Then we introduce how to build static meshes that construct the arena and other issues like special effects, victim and light. For robot building, we introduce the robot model and the procedure of building robot. Then I explain the details about constructing the robot. And at last, an example of robot will be presented.

3. 3 Building Arena Components Static meshes (Geometric models, obstacles) Special effects (mirror) Victims Lights Unreal Editor The interface UnrealEd Manual: Interface http://udn.epicgames.com/Two/UnrealEdInterface The basic operations Introduction to UnrealEd http://udn.epicgames.com/Two/IntroToUnrealEd An arena includes static meshes of the geometric models and obstacles and special effects like mirror and victims and lights. Unreal editor is the 3d authoring tool of unreal engine that helps user build unreal maps. We will build our arenas in Unreal Editor. The interface looks like this. It has different views of the 3d world, top view, front view and side view, a tool bar helps you create, adjust model and the material browser helps you find the materials. With Unreal editor, you can create or add a model, adjust the model and assemble the models together. You can also add some effect into the world. For example, we can add lights, sky box etc. to the world.An arena includes static meshes of the geometric models and obstacles and special effects like mirror and victims and lights. Unreal editor is the 3d authoring tool of unreal engine that helps user build unreal maps. We will build our arenas in Unreal Editor. The interface looks like this. It has different views of the 3d world, top view, front view and side view, a tool bar helps you create, adjust model and the material browser helps you find the materials. With Unreal editor, you can create or add a model, adjust the model and assemble the models together. You can also add some effect into the world. For example, we can add lights, sky box etc. to the world.

4. 4 Building Arena (cont.) Breakaway Example Breakaway Example http://udn.epicgames.com/Two/BreakAwayExample The workflow Usually, the procedure of building an unreal map is that 1) create the world space 2) build the terrain 3) build the BSP area 4) add the world geometry, the static meshs 5) add effects and 6) polish the map. For our arena building, the workflow is that create the world space, add/adjust/align the static meshes, then we can add victims, special effects and lights. Then we add �player start� and save the arena. �Player start� is default place to start the game. We will introduce static mesh, victim, special effect and light one by one.Usually, the procedure of building an unreal map is that 1) create the world space 2) build the terrain 3) build the BSP area 4) add the world geometry, the static meshs 5) add effects and 6) polish the map. For our arena building, the workflow is that create the world space, add/adjust/align the static meshes, then we can add victims, special effects and lights. Then we add �player start� and save the arena. �Player start� is default place to start the game. We will introduce static mesh, victim, special effect and light one by one.

5. 5 Building Arena (cont.) Static mesh USARSim static mesh Build your static mesh Build mesh Texture Convert to static mesh Save the static mesh Build mesh Build BSP mesh BSP Brushes http://udn.epicgames.com/Two/BspBrushesTutorial Static mesh. In USARSim, we provide some static meshes like boards, pillars, stair, ladder, pipe for you. So you can quickly build your arena by assemble them together in the Unreal editor. For example, the NIST arenas are built by these static meshes. You can also build your own static mesh. The procedure of building static mesh is to build a mesh, texture it and convert it to static mesh and then save it. There are two ways to build a mesh. One is directly creating it and one is importing it from other existing models. To create the mesh, you can build BSP brushStatic mesh. In USARSim, we provide some static meshes like boards, pillars, stair, ladder, pipe for you. So you can quickly build your arena by assemble them together in the Unreal editor. For example, the NIST arenas are built by these static meshes. You can also build your own static mesh. The procedure of building static mesh is to build a mesh, texture it and convert it to static mesh and then save it. There are two ways to build a mesh. One is directly creating it and one is importing it from other existing models. To create the mesh, you can build BSP brush

6. 6 Building Arena (cont.) Brush Clipping http://udn.epicgames.com/Two/BrushClipping 2D Shape Editor http://udn.epicgames.com/Two/ShapeEditor Import the existing mesh Supported format: ASE, DXF, LWO etc. Export from Max/Maya (ActorX plug-in) http://udn.epicgames.com/Two/ActorXTutorial And then edit it, for example clipping the brush. We also can create the brush from 2d shape. For example, create the 2d shape and then extrude or rotate it to get the brush. To import the mesh, you read in the file in supported format, like ase, dxf, lwo etc. Or we can use the plug-in to export the model from other authoring tools to unreal editor. ActorX is the one of the plug-ins that can export your model in Max or Maya to unreal editor.And then edit it, for example clipping the brush. We also can create the brush from 2d shape. For example, create the 2d shape and then extrude or rotate it to get the brush. To import the mesh, you read in the file in supported format, like ase, dxf, lwo etc. Or we can use the plug-in to export the model from other authoring tools to unreal editor. ActorX is the one of the plug-ins that can export your model in Max or Maya to unreal editor.

7. 7 Building Arena (cont.) Texture Unreal Texturing Guide http://udn.epicgames.com/Two/UnrealTexturing Import texture from bmp, pcx, tga, dds etc file. Texture dimensions in powers of 2 Using UnrealEd texture browser Convert to static mesh Add collision mesh Save the static mesh Package, Group & Name Special effects Materials http://udn.epicgames.com/Two/MaterialTutorial Mirror Security Cameras http://angelmapper.com/tutorials/securitycamera.htm After we have the mesh, we need to texture it. To do this, we select a picture from the texture browser and then put it on the surface of the mesh. In unreal editor, we can build our own texture by importing it from bmp, pxc, tga or dds image. The size of the image must be the powers of 2 and don�t forget save your textures. After we are satisfy to the mesh, we can transfer it to a static mesh. And then we may need to add collision mesh to the static mesh. Collision mesh is use by unreal to calculate collision. It decides the collision volume of the static mesh. At last, don�t forget to save the static mesh. I will show you the procedure of building static mesh. <DEMO> Ok, for special effects. We can build special materials like glass. And we also can build the effect of mirror. The details are explained in these two papers. This picture is the similar effect of mirror.After we have the mesh, we need to texture it. To do this, we select a picture from the texture browser and then put it on the surface of the mesh. In unreal editor, we can build our own texture by importing it from bmp, pxc, tga or dds image. The size of the image must be the powers of 2 and don�t forget save your textures. After we are satisfy to the mesh, we can transfer it to a static mesh. And then we may need to add collision mesh to the static mesh. Collision mesh is use by unreal to calculate collision. It decides the collision volume of the static mesh. At last, don�t forget to save the static mesh. I will show you the procedure of building static mesh. <DEMO> Ok, for special effects. We can build special materials like glass. And we also can build the effect of mirror. The details are explained in these two papers. This picture is the similar effect of mirror.

8. 8 Building Arena (cont.) Victim Set the skeletal mesh Specify actions based on bones start/end position moving speed Light Lighting Basics http://udn.epicgames.com/Two/LightingBasics Add Lights Specify properties Victims are simulated by skeletal meshes with moving limbs. Every mesh has it�s own bones and we can specify how the bones move. Light effect is achieved by adding light into the arena. This is the example effect of lighting.Victims are simulated by skeletal meshes with moving limbs. Every mesh has it�s own bones and we can specify how the bones move. Light effect is achieved by adding light into the arena. This is the example effect of lighting.

9. 9 Building Robot The robot model Objectives Encapsulate the programming details Building robot by assembling Components Chassis ? Parts Joints ? Attached auxiliary items Method Connect chassis and parts through joints Attach auxiliary items to chassis or parts In USARSim, we use robot model to simulate robot. The idea is building configurable robot. We encapsulate the programming details in the model and let user build robot by assembling the robot parts. In the model, a robot includes one chassis, multiple parts and joints and attached auxiliary items like sensor, camera, headlight. The chassis and parts are connected through joints and auxiliary items are directly attached to chassis or parts.In USARSim, we use robot model to simulate robot. The idea is building configurable robot. We encapsulate the programming details in the model and let user build robot by assembling the robot parts. In the model, a robot includes one chassis, multiple parts and joints and attached auxiliary items like sensor, camera, headlight. The chassis and parts are connected through joints and auxiliary items are directly attached to chassis or parts.

10. 10 Building Robot (cont) Build robot Prepare geometric models (modeling) Build static mesh(es) Make sure the geometric model has the correct x,y,z axes Construct the robot (configuring) Create the robot class Prepare the attributes and objects used for your robot Connect the parts Mount the auxiliary items Customize the robot (programming) Optional: Introduced in Advanced Session Basically, we need three steps to build a robot. At first we prepare the geometric models used for the robot. Then we configure the robot model to assemble the robot. Then we customize the robot if we want to add some functions not provided by the model. To construct the robot, we will create the robot class and prepare the properties of the robot and its components. And then we edit the configuration file to connect the parts and chassis and mount the auxiliary items.Basically, we need three steps to build a robot. At first we prepare the geometric models used for the robot. Then we configure the robot model to assemble the robot. Then we customize the robot if we want to add some functions not provided by the model. To construct the robot, we will create the robot class and prepare the properties of the robot and its components. And then we edit the configuration file to connect the parts and chassis and mount the auxiliary items.

11. 11 Building Robot (cont.) Construct the robot Create the robot class don't forget to change ut2003.ini Prepare the attributes Overall attributes MotorTorque, batteryLife, FlipTorque etc. Chassis attributes ChassisMass, StaticMesh, DrawScale, Kparams etc. Parts attributes Karma physical parameters: KarmaParams Use it at least once in defaultproperties Steering and tire parameters: TireRollFriction, TireLateralFriction, TireSlipRate etc. Compile the robot class (ucc make) A robot class looks like this. It extends from KRobot, the robot model, and use the configuration file USAR. In defaultproperties we define the properties of the robot. For example, we define the overall attributes like motortorque, battery life etc. The chassis attributes like the chassismass, the geometric model and scale and its physical attributes, the karma parameters. We also define the attributes used for the parts. For example, the physical attributes for the linkages and the tire attributes for the wheels.A robot class looks like this. It extends from KRobot, the robot model, and use the configuration file USAR. In defaultproperties we define the properties of the robot. For example, we define the overall attributes like motortorque, battery life etc. The chassis attributes like the chassismass, the geometric model and scale and its physical attributes, the karma parameters. We also define the attributes used for the parts. For example, the physical attributes for the linkages and the tire attributes for the wheels.

12. 12 Building Robot (cont.) Prepare the parts Linkage KDPart class Tire Create your class based on KTire class Specify StaticMesh, DreawScale, Kparams etc. Compile the tire class Connect chassis and parts Joint-Part pairs Connect a part to its parent through car wheel joint To build the robot, we need to prepare the parts. There are two kinds of parts, one is linkage and one tire. Usually, we needn�t create our own linkage class. For tire, we need to create our tire class. The class extends from KTire and we define the geometry model, scale and physical properties in this class. After we prepared all the components, we can assemble them by connecting them together. A part and joint construct the Joint-Part pair. This pair defines how the part is connected with its parent through the joint. The joint used in our robot model is car wheel joint. They are connected through two axes. One is hinge axis and one is steering axis.To build the robot, we need to prepare the parts. There are two kinds of parts, one is linkage and one tire. Usually, we needn�t create our own linkage class. For tire, we need to create our tire class. The class extends from KTire and we define the geometry model, scale and physical properties in this class. After we prepared all the components, we can assemble them by connecting them together. A part and joint construct the Joint-Part pair. This pair defines how the part is connected with its parent through the joint. The joint used in our robot model is car wheel joint. They are connected through two axes. One is hinge axis and one is steering axis.

13. 13 Building Robot (cont.) JointPart structure Part�s attributes: name, class, mesh, scale etc. Joint�s attributes: parent, two connect axes� position and direction etc. Assemble robot Create you robot section in usar.ini file Define the joint-part pairs The structure of the Joint-Part pair looks like this. It includes the part�s attributes, like name, class, geometric model, scale and physical properties, and the attributes of the joint which includes the parent, the part it will connect to, and two connection axes� position, direction and other attributes. We actually connect the parts and chassis by edit the usar.ini file. In the file, we add the robot section and a serials of JointPart definitions.The structure of the Joint-Part pair looks like this. It includes the part�s attributes, like name, class, geometric model, scale and physical properties, and the attributes of the joint which includes the parent, the part it will connect to, and two connection axes� position, direction and other attributes. We actually connect the parts and chassis by edit the usar.ini file. In the file, we add the robot section and a serials of JointPart definitions.

14. 14 Building Robot (cont.) Mount the auxiliary items Method Directly attach to chassis or part Definition Structure Item, parent Mount position and direction Configure In the robot section of usar.ini, define: Sensor(s) Camera Headlight After we assembled the robot, we can mount the auxiliary items to the robot through specify the sIthem structure. This structure define the item we want to add, the item class and name, and its parent the item will attach to. It also defines the mount position and direction. In the configuration file, we use the sItem structure to define the sensors, camera and headlight of the robot.After we assembled the robot, we can mount the auxiliary items to the robot through specify the sIthem structure. This structure define the item we want to add, the item class and name, and its parent the item will attach to. It also defines the mount position and direction. In the configuration file, we use the sItem structure to define the sensors, camera and headlight of the robot.

15. 15 Building Robot (cont.) Decide the mount or. connect position Calculate the position The position relative to its parent�s geometric center Pos = (child�s center pos) � (parent�s center pos) Tips (using the t3d file) Assemble the robot in Unreal Editor Export it to t3d file In the t3d file, find out the parts and chassis� position calculate the mount/connect position The position used in sItem and joint-part structure is relative value. It�s the position relative to its parent�s geometric center. That is, the position is gotten by subtracting the parent�s absolute position from the child�s absolute position. We can use the t3d file to help us get these relative values. We at first assemble the robot in the Unreal Editor. Then we export it to t3d file. A t3d file looks like this. In this file, we can find the location of the parts and chassis. With the location, we can calculate the mount or connect position.The position used in sItem and joint-part structure is relative value. It�s the position relative to its parent�s geometric center. That is, the position is gotten by subtracting the parent�s absolute position from the child�s absolute position. We can use the t3d file to help us get these relative values. We at first assemble the robot in the Unreal Editor. Then we export it to t3d file. A t3d file looks like this. In this file, we can find the location of the parts and chassis. With the location, we can calculate the mount or connect position.

16. 16 Building Robot (cont.) Example This is the configuration of the P2DX robot. The chassis� mass is 4. The wheels are connected to the chassis. The camera base is connected to the chassis and camera pan frame is connected to the camera base. The camera and headlight are attached to the camera tilt frame and the sensors are mounted to the chassis.This is the configuration of the P2DX robot. The chassis� mass is 4. The wheels are connected to the chassis. The camera base is connected to the chassis and camera pan frame is connected to the camera base. The camera and headlight are attached to the camera tilt frame and the sensors are mounted to the chassis.

17. 17 Summary Building arena by UnrealEd Static mesh Mesh ? Texture ? Convert Victims Special effect Light Building robot Prepare geometric models Construct the robot by configuration Properties ? JointPart structure ? sItem structure Customize the robot In summary, we use Unreal Editor to build arena. An arena usually includes static meshes, victims, special effects and lights. To build a static mesh we can create a mesh in unreal editor or import the mesh from other authoring tools. We can use texture to polish the mesh. And static mesh is accompanied with collision mesh that define the collision volume of the static mesh. There are basically three steps to build robot. We at first, prepare the geometric models of the robot. Then we assemble the robot by creating a robot class and configuring the robot. At last, we can customize the robot if we want.In summary, we use Unreal Editor to build arena. An arena usually includes static meshes, victims, special effects and lights. To build a static mesh we can create a mesh in unreal editor or import the mesh from other authoring tools. We can use texture to polish the mesh. And static mesh is accompanied with collision mesh that define the collision volume of the static mesh. There are basically three steps to build robot. We at first, prepare the geometric models of the robot. Then we assemble the robot by creating a robot class and configuring the robot. At last, we can customize the robot if we want.