Populates an attribute with ramped values.
An attribute is created on the Input Surface containing the control vertices of a ramp.
The Name specifies a surface rate attribute where the ramp data is placed.
For Houdini, surface rate could be referred to as 'detail class'.
A specified number of evenly spaced Samples are evaluated from the ramp widget
and stored in the attribute, each scaled by Max.
tested in Houdini
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