OpenVSP Conformal Components
This section provides tutorials and guidance for the OpenVSP Conformal component and how this geometry changes depending on the type of parent it is based on. The guidance also covers how to define the Conformal and trim the volume in different directions.
Encyclopedia
Updated Sep 25, 2025
Introduction
This video introduces the Conformal component and illustrates some of the defining parameters and uses within your model. A Conformal component inherits the traits and shape of the Parent component that it is attached to. Note that a Conformal may only be added as a Child to components that typically have volume e.g., Pod, Fuselage, Stack, Prop, Wing, etc.
Conformal geometries have many use cases including wing tanks, fuselage internal volumes, clearance envelopes, and negative volume trimming geometry. Also, Comformals may be placed at any location in the model including outside of the model.
Brandon Litherland
Aerospace Engineer
Offset Distance
The Conformal offset distance is a physical normal distance between the Parent component surface and the Conformal surface. The value entered in the Offset field will be in the same units as your model. Note that you may enter either positive (into the body) or negative (outside the body) offset values in the Offset field.
Negative offset distance creates an envelope of defined thickness around the parent geometry. However, this is somewhat of an unusual application and users should inspect the conformal body for any errors before moving on. A zero offset distance essentially makes a volumetric copy of the geometry that always exactly matches the parent. There are also no limits on how many Conformals are assigned to a single parent so you could feasibly drive many copies from a single geometry.
Brandon Litherland
Aerospace Engineer
Trimming in U
Conformal components may be trimmed in the U, V (W), or Chord directions depending on the type of Parent component. In this tutorial, we will cover how to use U-trimming to clip away some of the Conformal component material. Note that for Body-type geometries such as Fuselage, Stack, or Pod, the U direction is along the length while the U direction for a Wing is along the span.
More recent versions of OpenVSP have enhanced U trimming options. For body-type geometries or wings, you can trim using either a percentage of the length or a fixed distance by checking the boxes next to "01" or "0D". For wings, you may use this option plus Eta (spanwise) trimming. Where normal U trimming sets a location along the wing arclength, the Eta trimming will always be at the set spanwise location, regardless of your U surface length.
Brandon Litherland
Aerospace Engineer
Trimming in V
Conformal components may be trimmed in the U, V (W), or Chord directions depending on the type of Parent component. This tutorial will focus on how to trim the Conformal in the V (W) direction using both V1 and V2 trimming and the importance of selecting appropriate beginning and end points for both. With version 3.34.0, OpenVSP introduced a more robust V-trimming feature as well as a simplified trimming by side feature that users will find to be much more friendly.
Use V trimming if you need to take a piece off at an angle. Otherwise, use side trimming to keep cuts normal to the geometry planes.
Brandon Litherland
Aerospace Engineer
Trimming in Chord
Conformal components may be trimmed in the U, V (W), or Chord directions depending on the type of Parent component. This tutorial will focus on how to trim Conformals in the Chord direction when attached to a Wing or Prop.
Chord trimming works very well when you have a good idea where your spars will be.
Brandon Litherland
Aerospace Engineer