Interactively Map Instance Objects on Surfaces

Instance Objects may mapped to surfaces interactively using a brush controlled by pointer/mouse. 

Configuring Interactive Brush for Instance Objects

Instance Object(s) must have an instance map set to use interactive brush feature.  To set an Instance Map associated with an Instance object, select the Instance object as Solid A and in the Texture dialog select map to use and choose Instance Map then Set.

Note: Initial instance map may be empty (all black texture) with no instance objects rendered on surface
Note: For brush to correlate to surface location Instance Map requires Scale to Surface Size option to be set in Instance Object dialog when using interactive feature.  This option scales instance map area:surface area ratio to 1:1

Setting Brush Shape and Effect

Open the Interactive map Brush dialog with the Interactive Brush button from the Instance Object dialog page.

Note: An Instance object must be selected as Solid A for dialog to be active.

Surface Area Coverage: Controls surface area covered by brush on instance surface.  For a large area surfaces brush resolution will be low as it's expanded over a large area.  Reducing area coverage of the brush allows entire resolution of brush map to cover a smaller area 

Brush Effects
     Add/Reduce: Add or reduces size of instance objects covered by brush area
     Average: Averages instance object size covered by brush area
     Procedural: Used to break up uniform brush gradient, adds or reduces size of instance objects covered by brush area

ES: Set "Ellipse Shape" from diamond-circular-square shapes

Setting Brush Location on an Instance Surface

Click on a surface with a previously associated instance object in scene using middle or front side button to place brush location, hold to drag
Using the Interactive Brush with Instance Objects

With brush set on a surface and 1 or more previously associated instance objects selected as Solid A use scroll wheel to apply instances using brush function.  Scroll forward adds instances, backward reduces/removes instance to surface area covered by brush.

Continuous Drag Feature: Instance objects can be continuously added/reduced while dragging location of brush around the instancing surface.  To engage,

1.  Select add/reduce action to be applied by quickly turning scroll wheel forward/back half a turn or more
2.  Hold side/middle button and drag brush around instancing surface

Note: Using side button to drag brush after setting scroll wheel direction (step #1 above) may be less particular to subsequent mouse wheel movements from depress/drag which may cancel previously set action due to unintended scroll wheel turns.

Example usage