Maya Tool - Screen Depth Dragger

[david-cattermole]

Description

It is common practice when modelling using cameras to move objects closer or farther away from a camera, in Screen Space. This can be difficult using native Maya tools.

We wish to select multiple transform nodes, Mesh vertexes, NURBS CVs, Mesh faces, etc, and move them towards or away a camera. The user should have precise control over the depth, using the mouse position.

The camera may be the active viewport, or (optionally) another camera in the scene.
A GUI should be added to allow the user to set the specific camera. The camera options would be;

• Active Viewport Camera
• camera1
• camera2
• etc..

Usage

With one transform.

1. Select a transform node.
2. Activate a viewport.
3. Run tool.
4. Drag mouse to set depth, relative to the current screen depth.
   The selected transform node is moved closer or farther away from the active viewport camera.
   The transform node is moved away keeping the transform pivot-point in screen-space.

With multiple transform nodes:

1. Select multiple transform nodes.
2. Activate a viewport.
3. Run tool
4. Drag mouse to set depth, relative to the current screen depth.
   The selected transform nodes are moved closer or farther away from the active viewport camera.
   The transforms all move away from their local pivot point.

Optionally, the user may wish to scale a transform node up/down proportionally so the object stays exactly matching in screen space, otherwise the default action should be to only translate and NOT scale the nodes.

For Mesh vertexes or NURBS CVs, scale is unneeded and will be skipped.

The tool should support a mixture of both Mesh/NURBs components and transform nodes selected at once.

Notes

• Only perspective cameras need to be supported.
• It may make sense to use a maya.cmds.draggerContext for this tool.
• This tool should have a hotkey set up to be effective.
• Use CTRL or ALT keys to change the default behaviour.
• This is similar to the Ok Pushy tool.