Dynamics Soft Bodies
Paint Soft Body Weights Tool
Using the Paint Soft Body Weights Tool, you can set goal weights on a soft body on a per particle basis by painting on the soft body surface. The tool provides color feedback so you know which parts of the soft body have particles with different goal weights. Weights display as a range of grayscale values, with a weight of 1 displaying as white and 0 as black.
To paint goal weights on a soft body:
Select the soft body you want to paint goal weights on. The soft body must have been created with goal weights. For information on creating soft bodies with goal weights, see the option description for Make Non-Soft a Goal.
Select the Paint Soft Body Weights Tool and open the Tool Settings editor (Soft/Rigid Bodies > Paint Soft Body Weights Tool > ).
The Paint Soft Body Weights Tool automatically detects the soft body and goalPP attributes and selects the soft body for painting.
You can select the soft body for painting without opening the Tool Settings window by right-clicking the soft body and selecting the particle node from the Paint command submenu.
*******NOTE for Joselu I.B.***********
Check that Color Feedback is turned on in the Display section of the Tool Settings editor. Color feedback helps you identify the weights on the surface by representing them as grayscale values (smaller values are darker, larger values are lighter).
Select a brush, paint operation, and value and define other settings as required. See Paint Soft Body Weights Tool settings.
Drag the brush across the soft body.
Flooding soft body goal weights
Flooding soft body goal weights is like taking a huge brush and applying its settings to all the particles on the soft body. When you flood a soft body, Maya changes the goal weight of each particle on the soft body according to the value and operation set for the Paint Soft Body Weights Tool.
To flood a soft body, follow the steps under To paint goal weights on a soft body:, but instead of painting in step 5, click the Flood button (hotkey: Alt f).
To smooth the transition between goal weights on a soft body, select the Smooth paint operation and flood the soft body.
Mapping soft body goal weights
Using the Paint Soft Body Weights Tool you can map particle attribute values onto a surface. The tool applies the mapped values to the soft body particle goal weights. For details on mapping, see "Mapping attributes" in Using Maya: Painting.
Painting soft body goal weight values on restricted areas
When you paint goal weights over selected vertices on a soft body, your strokes are applied only to the goal weights for the particles corresponding with the selected vertices. In effect, the unselected vertices act as a mask, where only selected vertices are affected by any weight painting or flooding you do.
Before defining the resticted area you must first create the soft body. For details on restricing the paint area surfaces, see "Restricting an area for painting" in Using Maya: Painting.
Paint Soft Body Weights Tool settings
To modify Paint Soft Body Weights Tool settings, select the Paint Soft Body Weights Tool and open the Tool Settings editor (Soft/Rigid Bodies > Paint Soft Body Weights Tool > ).
Paint Attributes settings are described below.
For details on Brush, Stroke, Stylus Pressure, Attribute Maps, and Display settings, see "Brush Tool settings (new architecture)" in Using Maya: Painting.
You can define hotkey combinations to change most of the settings without opening the Tool Settings editor. For details on setting hotkey combinations, see "Defining Artisan hotkeys" in Using Maya: Painting.
Displays the name of the particle node selected to paint and the attribute you are painting (goalPP weights). To select another particle node to paint, click this button and select the appropriate particle node goalPP weights name. By default, the tool selects the first particle node it detects.
When you select the soft body, the Paint Soft Body Weight Tool automatically detects the particle node and goalPP attribute on the soft body. The name of the node and attribute displays on the top button.
Sets a filter so that only particle nodes display on the menu for the button above this one. You are painting particle goalPP weights with the Paint Soft Body Weights Tool, so you do not need to change this filter unless you want to paint other types of attributes.
Select an operation to define how you want painted goalPP values to be affected.
Replaces the goalPP values for the soft body particles you paint over with the specified Value and Opacity.
Adds the specified Value and Opacity to the current goalPP values you paint over. If the value is negative (possible if you set Min or Max to a negative value), the value actually decreases.
Scales the current goalPP values you paint over by the Value and Opacity factors.
Changes the goalPP values to be the average values of the surrounding goalPP values.
Set the value to apply when you perform any of the painting operations.
Set the minimum and maximum possible paint values. By default, you can paint values between 0 and 1. Setting the Min/Max Values you can extend or narrow the range of values. Negative values are useful for subtracting weight. For example, if you set Min Value to -1, Value to -0.5, and select Add for the operation, you would subtract 0.5 from the weight of vertices you paint. Positive values are added.
To help you differentiate paint values when you paint with ranges greater than 0 to 1 (for example, -5 to 5), and to maximize the range of values that display when you paint values with ranges between 0 to 1 (for example, 0.2 to 0.8), set Min Color and Max Color (in the Display section) to correspond with the Min/Max values.
Select whether you want to clamp the values within a specified range when you paint, regardless of the Value set.
Turn this on to clamp the lower value to the Clamp Value specified below. For example, if you clamp Lower and set the lower Clamp Value to 0.5, the values you paint will never be less than 0.5, even if you set the Value to 0.25.
Turn this on to clamp the upper value to the Clamp Value specified below. For example, if you clamp Upper, set the upper Clamp Value to 0.75, and set Value to 1, the values you paint will never be greater than 0.75.
Set the Lower and Upper values for clamping.
Click Flood to apply the brush settings to all the particle goals on the selected soft body. The result depends on the brush settings defined when you perform the flood.
If you are painting a three channel attribute (RGB or XYZ), select the channel you want to paint. Soft body goalPP weight is a single channel attribute, therefore you do not need to change this setting.
Glad to hear you found it.
Originally posted by Joselu I.B.
I´ve found the problem, it is a Maya LE 3.5