FX Tool: Volume Attribute Transfer Meta surface node

Transfers point attributes from a set of points to a volume

All

Parameters

Inputs

Note Author: Peter Claes Date: 21/08/2009

Tip

-) Start with a low resolution input volume first.

-) Make sure the bounds of the volume encompass the template geometry

-) Attributes with negative values will be transferred but are currently not displayed in the viewport. (If you want to check you can perform an absolute value on the density inside a volume vop, just for visualizing the data in the viewport)

-) You can use a “pscale” (float) attribute on the template points which will scale the metaballs on a per point level.

-) The resulting field is typically used as custom Sop Scalar or Sop Vector field in DOPS or in case of a vector field (such as velocity) it can be used inside of POPS to Advect particles.

-) For now only one attribute can be transferred, if you need to transfer several attributes, you will need to put down several Volume Attribute Transfer Meta SOPs (you can make reference copies if you want most of the settings to be the same) Use a merge sop to bring all the fields back together.

-) Tangent vectors to curves, sampled surface normals or particle velocities can provide interesting custom velocity fields.

Parameters

Volume Settings

Volume Field Name

Used to set the name of the volume field that will be output. If the output field is a vector field, eg. vel (velocity), the scalar primitives that will be output will be vel.x, vel.y and vel.z

Attribute Settings

Attribute dropdown list	Choose from a list of preset attributes: “density”, “age”, “temperature”, “velocity” and “color”. For transferring a custom attribute, set the dropdown menu to “other”
Attribute Type	This defines the type of attribute, this will also define the output type of the volume. “float” will result in a scalar field, “vector” and “float” will result in a vector field.
Attribute	Defines the name of the attribute you want to transfer (for now only one attribute can be transferred at a time).
Blend Operation	Defines the type of operation that takes place inside the look-up. The addition is more suited for density and temperature, whereas the average is more suited for velocity and color.
Attribute multiplier	A multiplier to scale the values of the attribute.

Transfer settings:

Use weight per metaball	When this checkbox is checked if a “weight” attribute is present on the template geometry, it will be used to define the weight per metaball.
Use pscale as weight	If the “pscale” attribute is present on the template geometry, and this checkbox is checked, the “pscale” is converted to “weight” for a fading effect rather than a scaling effect.
Transfer Radius	Defines the global radius of the metaballs.
Weight	The global weight of the metaballs

Inputs

Input 1	Volume geometry to transfer attributes to.
Input 2	Geometry to transfer point attributes from, this can be a polygonal mesh, but only the point information is transferred (You could scatter points over a surface if more points are required).

Usages in other examples

Example name	Example for

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