kismert on April 25th 2006
2316 views

Camera Positioning Ideas

Hello group:

I am submitting some ideas on camera and 3D object positioning.

Gliding The Camera
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One viewpoint positioning mode that I have seen in CAD visualization programs is gliding. It works like this:

* Velocity controls -- Three keys for Faster, Slower and Stop. You can use these to go forwards, backwards or stop.
* The center of the window is always the visual direction of travel. It is what the camera is pointed at.
* You move the camera by simply pointing the mouse within the window. The pointer's deviation from center determines the direction and rate of change (the further from center, the faster)
* When stopped, pointing causes the camera to rotate about it's center.
  The nice thing about gliding is you never have to move your cursor out of the viewport. Your camera is free to manuever within the visual cone. No dragging - click to start, and click to end. The cursor can become a paper glider icon when gliding.

Picture Frame in Viewfinder
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The camera viewfinder in the renderer can be any size if you put a picture frame in it showing what will be rendered. The picture frame and the preview pane don't have to be the same size. The user can size the viewfinder larger than the render preview pane, to more easily acquire and frame an object.

Rotation on One Axis
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When rotating 3D objects, you could make the X, Y and Z vertexes 'hot spots'. When you float the cursor over a vertex, it changes shape. You can then drag and rotate about just that axis.

3D Editor Window From Camera Button
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You have a Camera from 3D Editor Button, which moves the camera to the current 3D editor view. Could you have the opposite, a "3D Editor Window From Camera" button which alignes the 3D Editor to the current camera view?

You may have tried some these, and found that they don't work, but I thought they would be worth mentioning.

-Ken

Vlasta on April 25th 2006 0

Thanks for the suggestions. Here is my point of view:

Rotation on One Axis - very useful, but it is not as easy to implemnt as it seems. For example, an object can be part of a group of objects, with applied rotation; should it rotate around the local or global X, Y, Z axes? We will try to implement something like this in the next version.

3D Editor Window From Camera Button - it is very easy to implement, could be part of a patch.

Gliding The Camera - sounds more intuitive than the current mouse-hiding mode. Maybe with a mechanism for object rotation it could be the perfect solution.

Picture Frame in Viewfinder - seems like it would make the problem even more complex. But maybe by specifying a rectangle, the zoom factor of the camera or its distance from the object could be automatically adjusted...

kismert on April 25th 2006 0

Another thought on gliding the camera: if you have a wheel mouse, you could roll the wheel to accelerate/decelerate, and click the wheel to stop.

> Rotation on One Axis ... should it rotate around the local
> or global X, Y, Z axes?

The greedy user says "Yes" 😊 If the default axes are global, then the default rotation should be global. If there is a way to select the axes for one object in a group, then rotation is local to that object.

> Picture Frame in Viewfinder - seems like it would make the
> problem even more complex...

My thought is the "picture frame" is just a fixed rectangle (or square) that sits centered in the viewfinder. The user can't change it. It just shows what portion of the viewfinder will be rendered in the preview pane.

But I have no clue about the difficulties involved, so maybe the suggestion is impractical.

-Ken

Vlasta on April 25th 2006 0

> My thought is the "picture frame" is just a fixed rectangle (or
> square) that sits centered in the viewfinder. The user can't change
> it. It just shows what portion of the viewfinder will be rendered in
> the preview pane.

Now I know what you mean - something to compensate for the different aspect ratio in the preview window and in the scene browser. Yes, that sound useful. I'll keep that in mind.