It has been tested in 3ds Max 2008, 3ds Max 2009 and 3ds Max 2010.
It should also work in 3ds Max 9 but not in earlier versions since it uses DotNet.

It allows the

• interactive selecting and deselecting of one or more lights based on their angle to a specified surface point,
• tweaking of the distance to the surface or light target,
• placement of the light to produce the desired diffuse or specular effects on the specified surface,
• interactive shifting of the light along a surface without changing the light's direction,
• interactive rotation of the lights around a specified surface point in polar coordinates based on the mouse moviement,
• placement of the light's target on the specified surface with optional Working Pivot support,
• interactive adjustment of the light's multiplier

The tool provides a set of MacroScripts which can be used as icon buttons, menu items or keyboard shortcuts, and a floating Options dialog.

LT! consists of one .MS source file defining the Screen Manipulator helper plugin, one .MCR file containing all MacroScripts, and 4 icon bitmap files for large and small icon sizes.

The .MS file can be copied into the \StdPlugs\Stdscripts folder, the \Plugins folder, or any folder listed in the plugin.ini file.
It should NOT be copied into the \Scripts\Startup folder!

The .BMP files should be copied into the \UI\Usericons folder of 3ds Max either in the User's Local Settings or the 3ds Max installation folder, depending on the 3ds Max installation setup.

After launching 3ds Max, the Category "LightTouch" will appear in the Customize User Interface dialog.
You can assign the ActionItems to keyboard shortcuts and/or place them in toolbars or menus according to your preferences.

• When enabled, LT will switch the selection filter to Lights (disallowing the selection of anything else in the scene) and will enable a timer which will be polling the state of the keyboard keys to perform the requested operations. In this mode, the mouse movement is captured directly and with the exception of selecting and deselecting, no Left Mouse Button clicking is required to manipulate the lights, resulting in a very fluid workflow. The text "LightTouch:" will appear in the lower left corner of the currently active viewport.
   
• When disabled, LT will switch the selection filter to its previous state and the word "LightTouch:" will disappear from the viewport. The timer will be deactivated and the tool will be turned off completely.

• By holding down the CTRL key and moving the mouse across the surface of scene geometry objects, the light with the least angle to the surface normal will be highlighted and marked by a line connecting the mouse point and the light. The name of the current Mode and the name of the light will be shown next to the light.
   
• To select the highlighted light, press the Left Mouse  Button.
   
• To deselect the highlighted light, hold down the ALT key and press the Left Mouse  Button.
   
• There are two additional option to this mode: Select One Light Only and Don't Test Selected Lights.
  • When Select One Light Only option is checked, selecting a light will automatically deselect any lights that were previously selected.
  • When the Don't Test Selected Lights option is checked, selected lights will not be considered by this mode anymore and the tool will jump to the next unselected light (if any).
     
• Since the selection filter is set to Lights, pressing CTRL + A (Select All) will select all lights in the scene.

• Hold down the SHIFT key and move the mouse up and down in screen space to increase/decrease the target distance of the selected lights.
   
• If multiple lights are selected, each light will move along its own local Z axis.

• Hold down the CTRL and SHIFT keys and move the mouse over geometry objects to define the location of the selected lights' target.
   
• If multiple lights are selected, all lights will be targeted at the same point.
   
• If the Working Pivot of 3ds Max is enabled (Use Working Pivot), the light will pivot around that point while pointing at the selected target point. This move is useful for targeting a light at a specific point while ensuring it passes through another point in space, for example adjusting a light to shine into a room at a specific object while always passing through the center of a window opening (where the Working Pivot would be placed).

• Make sure the Diffuse mode is enabled, hold down the CTRL and ALT keys and move the mouse over geometry objects. The existing target distance of each light will be used to project the new position of the light along the surface's normal vector.
   
• If multiple lights are selected, all lights will be moved to shine along the SAME line, although their target distances (and thus final distances to the surface point) will be different.

• Make sure the Surface Shift mode is enabled, hold down the CTRL and ALT keys and move the mouse over geometry objects. A line will be drawn to the selected light, showing the distance of the light to the LT gizmo. This distance will be preserved, resulting in the light being offset as the gizmo moves.
   
• If multiple lights are selected, all lights will be moved in parallel based on their original distance to the first click point, keeping their existing target distances and orienations.

• Make sure the Trackball mode is enabled, place the mouse at the center of rotation and hold down the CTRL and ALT keys. Now move the mouse horizontally in screen space to define the azimuth angle and vertically to change the zenith.
   
• The zenith plane is defined by the surface normal at the mouse point and the Z axis of the light.
   
• If multiple lights are selected, each light will preserve its target distance and will use its initial orientation as the base angle to increment.
   
• To adjust the Azimuth only, open the LightTouch Options dialog and enable the X mode. The vertical motion of the mouse will be ignored.
   
• To adjust the Zenith only, open the LightTouch Options dialog and enable the Y mode. The vertical motion of the mouse will be ignored.

• Press and hold the ALT and SHIFT keys and move the mouse up and down in screen space to adjust the Multiplier value of the selected lights.
   
• Photometric lights use a Multiplier expressed in %. The tool will adjust correspondingly. NOTE: Not all Photometric classes were taken into account in version 0.5. This has been fixed in v0.51. In v0.52, VRayLight is also supported with a factor of 10.
   
• If multiple lights are selected, each light will be adjusted relatively to its original multiplier value, thus boosting or dimming the scene illumination.

• Press and hold the CTRL, ALT and SHIFT keys and move the mouse over a surface to place the highlight. The light position and direction will be set to cause the light to bounce back into the viewer's position according to the surface normal and laws of reflection.
   
• If multiple lights are selected, all lights will be placed along the same line but at their existing target distances to the specular highlight point.

• To enable the Undo System, either uncheck the Disable Undo System Icon, or open the LightTouch Options dialog and uncheck the checkbox there.
   
• When the LT Undo System is turned on, light selection and changes to light properties like position, orientation, target distance and position, multiplier etc will be recorded in a single undo record which will contain all changes from the first pressing of a keyboard CTRL/SHIFT/ALT combination until the releasing of the keys or the beginning of a new combination. An Undo record with the name of the performed LT operation will appear in the 3ds Max Undo buffer and the operation will be fully undoable.
   
• When the Undo System is turned off, changes to lights via LT will NOT be recorded in the Undo buffer.