TYPE: SOP
TITLE: Paint SOP

The basic operation of the Paint brush is to apply a stencil to the incoming
geometry.  Then, paint is applied to the geometry points through that stencil.

Alpha is treated in a special manner.  It is only used when Accumulate
Alpha is turned on.  In this case, the opacity of the brush is added
to the alpha (to a maximum of 1).  Also, the original alpha is taken
into account when doing the blend (as point colours are traditionaly
not premultiplied).

For more details on the interactive options, including the different
operations, look at the paint state help.

Parameters:
Operation
    Operation       - The operation used by Apply To All.
    Merge Mode      - How the color is to be applied to the surface.
	Replace - The result is a blend between the original colour
		  and the brush colour according to the brush alpha.
	Add	- The scaled brush colour is added to the original
		  geometry colour.
	Subtract - The scaled brush colour is subtracted from the
		   original geometry colour.
	Multiply - The result of multiplying the brush colour by the
		   original geometry colour is blended into the
		   original colour by the brush opacity.
	Hue	-  The hue of the original colour is replaced by that
		   of the brush colour.  The result is blended into
		   the original colour.
	Saturation - The saturation of the original colour is chnaged
		     to that of the brush colour.  The result is then
		     blended into the original colour.
	Lightness - The lightnes sof the original colour is changed to
		    the brush colour.  The result is then blended with
		    the original colour.
	Red	- Replace only the red (first) channel.
	Green	- Replace only the green (second) channel.
	Blue	- Repalce only the blue (third) channel.
	Invert	- Does not use the brush colour.  Instead, does a
		  replace operation with the inverse (1.0 - orig) of
		  the original colour.
	Custom	- When in custom mode, the brush colour will be
		  re-evaluated for every point.  The evaluated colour
		  is then blended using replace semantics.  Local
		  variables are present, so you can paint with ($BBX,
		  $BBY, $BBZ).
    Accumulate To Stencil - By default, the operation is applied and the stencil
                      cleared after every brush stroke. With this set, the 
                      stencil is not cleared until "Apply and Clear Stencil" 
                      is pressed.
    Apply & Clear Stencil - Applies the operation and clears the stencil. This
                      is equivalent to right-clicking in the viewport.
    Foreground/Background - Colors to apply unless bitmap stamping is enabled.
                      If "Accumulate To Stencil" is on, the left mouse
                      does foreground and the middle mouse erases. /fg /bg
    Stamp Bitmap Instead Of FG/BG Color - If set, the color channels of the
                      bitmap are used directly rather than the brush color.
    Apply To All    - Paints all of the selected geometry.
    Reset All Changes - Restores geometry to initial state.
    Create Missing Color And Alpha Attributes - Adds the "Cd" and "Alpha" point
                      attributes if not present and not overridden and required.
    Accumulate Alpha - When set gives a paint-on-glass effect.  The
                      painting on the surface will increase the alpha,
                      so painted areas become visible.  Note this has
                      no effect on areas with alpha of one.
    Override Color  - If enabled, it will paint onto the specified attribute 
                      rather than the default "Cd".
    Override Alpha  - Same, but changes the "Alpha" attribute name.
    Visualize Attribute - Whether to do a false color visualization of
                      the overridden attribute and what range to map to.
    Visualize Mode  - How to map the attribute value to a colour.
Brush
    Shape           - The basic shape of the brush: circle, square, or bitmap.
    Bitmap          - What bitmap to use. The alpha channel becomes the brush.
    Radius          - The radius of the brush.                           /radius
    Radius Pressure - This controls how much effect the pressure of a
		      stylus will have on the radius.  A value of 1
		      means the radius will go from 0 to the amount in
		      Radius.  A value of 0 will mean the radius will
		      always be constant, regardless of pressure.  A
		      value of 0.5 will mean the radius will be scaled
		      between one half of Radius and Radius.
		      /radiuspressure
    Depth	    - If set, this limits how far the brush will
		      paint along its axis.  This can be used if
		      connectivity is disabled to limit the effect of
		      the brush.  The first parameter is how deep
		      below the surface the brush should penetrate.
		      The second is how high above the surface it
		      should stop.  These values can be negative.  /depth
    Brush Angle     - How far to rotate the brush.                   /brushangle
    Brush Squash    - Amount to squash the brush in the y direction before
                      rotation.                                          /squash
    Opacity         - The amount to affect the stencil mask.            /opacity
    Opacity Pressure - This controls the how much effect the pressure
		      of a stylus will have on the opacity.  It obeys
		      the same scaling as the Radius Pressure
		      /opacitypressure
    Brush Splatter  - A random noise in the brush's opacity based upon
                      the position on the brush.                  /brushsplatter
    Paper Grain     - A random noise on the object's stencil mask based 
                      on the object position.                        /papergrain
    Soft Edge       - Percentage of the brush to be rolled off.        /softedge
    Kernel Function - Which metaball kernel to use for the roll off.
    Up Vector Type  - How the brush should be oriented on the surface:
        Stroke Direction - Oriented in the direction in which the brush moves.
        Fixed		 - Oriented as specified in the Up Vector field.
    Up Vector       - The fixed up vector to orient brush to.          /upvector
Symmetry
    Reflective	    - If set, the brush will perform reflective
		      symmetry.  Any strokes will be mirrored along
		      the plane of symmetry.
    Rotational	    - If set, the brush will perform rotational
		      symmetry.  Any strokes will be rotated around
		      the axis of symmetry.
    Axis	    - This defines the normal of the plane of symmetry
		      for reflection and the axis of symmetry for
		      rotation.		/symaxisx /symaxisy /symaxisz
    Origin	    - This defines the origin of the plane of symmetry
		      for reflection and the origin of the axis of
		      symmetry for rotation.  /symorigx /symorigy
		      /symorigz
    Number of Rotate - This defines the degree of rotational symmetry.
		      A degree of 3 means the stroke will be applied
		      3 times at 120 degree seperation.  A value of 5
		      will perform the stroke 5 times with 72 degrees
		      of seperation.  /symrot
    Reflection Dist - This is the distance of the plane of symmetry
		      from the origin of symmetry.  /symdist
    UV Reflection   - If set, the brush will reflect when brushing is
		      done in the UV viewport.
    UV Origin	    - The origin of the line of reflection in the UV
		      viewport. /symuvorig
    UV Angle	    - The angle of the line of reflection in the UV
		      viewport.  0 will mirror about the U axis,
		      90 will mirror about the V axis. /symuvangle
Stroke
    Orient Brush to Surface - Switches between the brush being perpendicular
                      to the surface or always oriented along the view
                      direction. If you are having trouble with a shaky brush,
                      try turning this off.
    Use Connectivity - If set, the tool will only affect points
		      connected to the closest point to the intersection.
		      This is usually a good thing, as it avoids
		      accidentally painting through the geometry (but
		      see the depth parameter), but can prevent
		      smoothly painting across seams.
    Realtime Mode   - Set this to paint geometry as it's deforming.

See Also: CapturePaint, Comb, Sculpt, Paint State(../sop_state/paint), UVBrush
