In mapping, modeling, and other 3D apps, there are a ton of different styles of moving the camera around to look at what you want to see. Such a seemingly small part of a mapping/modeling program has huge effects on my ability to get stuff done and my comfortability with the interface to the point that its a make-or-break thing for me.
Worldcraft, and most FPS games: mouselook for pitch and yaw, and wasd for forward/backward movement and strafing. I love this style because you can move around the world/models like you are flying. The biggest disadvantage is the blatant lack of control of the "roll" of the camera, which is important in modeling. Also, there is no built in tool to rotate around a specific object, although if you are good at keeping an object centered on the screen while strafing around it, then it's not too hard to achieve the same effect.
QuArK: mouselook with very poor strafing control. Plus you can only do mouselook when you are not moving. Basically to move around you have to move, change camera angle, move, change camera angle, etc. This is the single reason why I stopped using QuArK if I dont need to despite its awesome features like duplicators, linear transformation abilities, and the tree hirearchy.
Camera placement: In most programs you can specifically create a "camera" object, and move it around in the 2D views. While this is fine and occasionally useful, It becomes annoying in programs where this is the only way to change the 3D view.
Nearly all 3D modeling apps (3ds max, Blender, Milkshape, etc): pan and rotate, with various ways to control the roll. Most 3D modeling programs offer variations on how it is done.
Rotation: whether rotation is done about the selected object, or some set distance in front of the screen. I prefer rotation around the selected object.
Zoom: Some programs let you move the camera through objects as you zoom in, while others just asymptotically move the camera closer and closer to the blocking object without every going through it. I'm up in the air on this one - its nice to be able to keep zooming in on the stuff you are working on without going through it, but on the other hand when working with complex models that have peices blocking other peices, your view can asymptotically zoom in on the wrong part of the model.
Roll: In some systems you grab near the outside of the screen to roll it, and near the inside of the screen to pitch and yaw. Blender uses this and I'm a big fan. Other programs use pitch and yaw mouselook, and have a special key for doing roll. Yet others (3D Cad programs like SolidWorks come to mind) control the roll of the screen based on the curl of your mousemovements. ie: if you move the mouse around the screen and back to the same point you started, the amount of roll is proportional to the area swept out by the mouse during the movement. Its very non-intuitive, but actually works pretty well when you get used to it.
My absolute favorite (though I have yet to find a program that does this) would be worldcraft style mouselook+wasd, combined with a special key that activates roll. For example, you would be zooming around your map/models with mouslook, then all of a sudden you hold down the middle mouse button and the mouse now controls the roll of the camera.
Anyways, what are all of your opinions on the subject?
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