   How to do Real-Time excvavtor's machine hand
  HI,Guys.  First,I'm sorry.My English is poor.  I'm a Programmer.I think to Develop a Real-Time excvavtor's machine hand motion.But I have no idea.How does do this?  I see a game used Unity3D Game Engine Done.  The Demo in here:http://www.vrart.cn/works/view/read/20081030/5922030702.shtml  I want know how to do it.   Thank you everyone.   
  I haven't done that sort of thing in Unity myself (and I don't have much experience with using joints in PhysX), but I would guess that the machine is constructed from multiple rigid bodies connected with motorized joints, and that the slider controls run the motors.As for the motion of the vehicle as a whole, I'd guess that forces and torques are applied in response to key presses to effect rotation and linear motion. As for the tracks and wheels, that might just be procedural animation.(Again though, these are all just guesses.)   ;  You'll have to build a 3D model of the excavator in a 3D program like Maya, Max or Blender. You'll then need to rig it, ie associate bones with parts of the 3D model and define constraints upon those bones.Once that is done you can then import it into Unity (which I beleive have support for many 3D formats supported by the above programs). Once imported you'll need to hook it up into a physics engine (if you want any type of non-scripted interaction with the world), like Havok, Bullet or PhysicX.Once you have a play bed, this next step is dependent upon how accurate you want the model to be. If you want a highly accurate physical simulation you'll need to export the 3D model and its bone constraints into the physics model and its constraint system. This will then give u a true 3D physical model for the excavator. You'll also have to add true actuators (ie true hydraulic actuators ) and their real attachment points if you want the model to actually move physically. If you only want a low quality simulation where you have an object which can be animated, you can skip the above step and use the 3D model as is but you will still need to create a 3D physical proxy in the physics system. You'll then need to associate some controls/command/mouse movement or UI elements to control your excavator model. Once all that is setup you should add some things in the play bed for your excavator to excavate, like a pile of bricks or something. Good Luck!-ddn   ;Quote:Once imported you'll need to hook it up into a physics engine (if you want any type of non-scripted interaction with the world), like Havok, Bullet or PhysicX.Unity uses PhysX for physics (it's incorporated directly into the Unity engine).   ;Quote:Original post by ddn3You'll have to build a 3D model of the excavator in a 3D program like Maya, Max or Blender. You'll then need to rig it, ie associate bones with parts of the 3D model and define constraints upon those bones.Once that is done you can then import it into Unity (which I beleive have support for many 3D formats supported by the above programs). Once imported you'll need to hook it up into a physics engine (if you want any type of non-scripted interaction with the world), like Havok, Bullet or PhysicX.Once you have a play bed, this next step is dependent upon how accurate you want the model to be. If you want a highly accurate physical simulation you'll need to export the 3D model and its bone constraints into the physics model and its constraint system. This will then give u a true 3D physical model for the excavator. You'll also have to add true actuators (ie true hydraulic actuators ) and their real attachment points if you want the model to actually move physically. If you only want a low quality simulation where you have an object which can be animated, you can skip the above step and use the 3D model as is but you will still need to create a 3D physical proxy in the physics system. You'll then need to associate some controls/command/mouse movement or UI elements to control your excavator model. Once all that is setup you should add some things in the play bed for your excavator to excavate, like a pile of bricks or something. Good Luck!-ddnHI,ddn.  I want to know a idea.Unity3d used PhysX for physics.Today i see a another Game name is ROADWORKS.SIMULATOR.MULTI3. This game with the game engine is also using it to operate an excavator。I think, Unity3D now used in more than excavator game. I gave up skinned mesh animation, want to program to calculate, because it is the length of the keyboard keys to real-time basis, a little bit up and down, so I thought, skeletal animation should not be for it. Do you have this example? I do not have There is too clear how to do it.;  Sorry I don't have access to Unity or a 3D program, but here is a thread on another forum which talks about making a rigged excavator maybe you can find their assets.http://boards.polycount.net/showthread.php?t=69253Good Luck!-ddn   