Surface from submesh : this check box let user have the ability to select closed lines to define submesh on the selected mesh. If this check box is checked, the Create button will be enabled, the Trim button will be disabled because surface from sub mesh will be trimmed in default;

Extract: a method of extracting sub meshes from meshes.

There are 3 methods to extract sub meshes:

Curve: extract sub-mesh by picking curves on the mesh to define closed areas. A trimmed surface will be created from the sub-mesh.When this type is selected, the generate button is activated.

Angle: by setting the angle value, pick a mesh face, make the mesh face grow outward under the angle constraint, and extract the sub mesh. When this type is selected, the angle change button is activated.

Curve&Untrim: extract sub-mesh by picking curves on the mesh to define closed areas. A untrimmed surface will be created from the sub-mesh.When this type is selected, the generate button is activated.

Increment: sets the incremental value of the angle change.

Seed: after you checked the from submesh button and choose Extract option as Angle, this button will be enabled. Click this button, select a mesh face as seed, then adjust the angle value, you will see the mesh face growing outward, you click Apply button to create a new surface. You can click this button to extract new submesh for new surface generation.

Create: after you checked the from submesh button, this button will be enabled. Click this button, select some lines to make closed loop, then click right-mouse button, a new surface with the specified tolerance will appear. If you would like to adjust the tolerance of the surface, reset Max Tol and click Apply button, the surface will update.

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Shape: topology shape of your mesh model.

For single surface from whole mesh, if your mesh model is like plane, choose plane homeomorphous; if your mesh model is like cylinder, choose cylinder homeomorphous;if your mesh model is like semisphere, choose semi_sphere homeomorphous.

For surface from submesh, the items include:

Free by point: create free-form surface by using point position only;

Free by topo: create free-form surface by using point position and mesh topology data;

Plane Primitive: create a plane primitive from submesh;

Sphere Primitive: create a sphere primitive from submesh;

Cylinder Primitive: create a cylinder primitive from submesh;

Cone Primitive: create a cone primitive from submesh;

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Set control number: this check box let user have the ability to set an initial control point number for the surface. Such as u = 43, v = 23. This check box is only designed for those users who would like to control the surface in advanced way. Sometimes, if user type a reasonable control point number, it will be helpful to increase the speed. Generally, however, user does not need to care this control number, the program will calculate a suitable number automatically.

Degree: surface degree in u-direction and v-direction.

Extending: the extending value which user wants the surface to extend in U-direction and V-direction.

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Max Tol: the maximum deviation between surface and mesh.

Smooth: the smooth controller of the surface.

Trim: to trim or untrim the generated surface with the boundary line of the mesh.

Reject: discard the surface.

New: pick a new mesh model to reconstruct a new surface, and the currently obtained surface will be retained.

Error: check this button to analyze the deviation error between mesh and surface.

Apply: user clicks this button to generate surface. After a surface is generated, if the tolerance is not desired, continue to click this button to get a surface with a desired tolerance.