Creates one or more ruled surfaces by pulling a group of surface curves at an angle to the normal of the original surface(s), or by pulling any number of curves at an angle to a pull vector. The curves can be continuous or disjoint.
The Multi-Surface Draft tool uses surface edges, curves on surface, isoparametric curves, and in Draft mode, even free curves, to create a ruled surface (or group of surfaces) that extends away at an angle to the original surface (or curve).
You can build a single surface across all of the input curves, provided that they are tangent continuous.
Normal – Creates a surface that extends away at a given angle from the normal of the underlying surface(s). By default, the new surface is normal to the underlying surface(s).
Draft – Creates a surface that extends away at a given angle from a specified pull direction vector. By default, the surface is parallel to the pull vector.
In this mode, you can individually select, or box-select, any combination of curves (even free curves), whether they are disjoint (non-touching), G0 (position continuous) or G1 (tangent continuous).
The initial angle between the new surface and the normal of the original surface (Normal type), or pull vector (Draft type). The default is 0.0. You can also change this value using the angle/length manipulator when you use the tool. (See Variable option below).
The initial length of the surface from the original curves. You can also change this value using the angle/length manipulator when you use the tool. (See Variable option below).
Default – The length of the flange is the length of the flange edge.
Projected – The length of the flange is the projected distance to the surface.
Select this option to raise or lower the midpoint or top of the draft surface so that the height or crown of the surface is proportional to the distance between the original curve and the top of the draft surface .
You can turn Proportional Crown on and off directly on the surface.
Controls the height of the crown. The value corresponds to a percentage of the distance between the two rails. The slider ranges from 0.0 to 0.1, but larger values can be entered into the field.
Flips the direction of the crown. Click the arrow of the proportional crown manipulator to Flip the crown direction directly on the model.
Radial off
Radial on
The Radial option creates a variation of the original draft surface. However, the radial surface does not follow the direction of the draft vector, so some radial draft surfaces may not meet the draft requirements. (The surface will fail the draft angle check in the Surface Evaluation diagnostic shader. The larger the angle between the default non-radial draft surface and the radial draft surface, the more likely the draft check will fail.)
To build a clean flange off a light weight curve that has been fit to a curve-on-surface, select Flange from Curve, From Surface.
To create a flange from a curve to a surface, select Flange from Curve, To Surface.Turn this option on to build draft surfaces on both sides of a curve simultaneously.
This option only appears if Double Sided is on. Turn it on to build only one surface, extending on both sides of the curve.
Select this option to handle corner conditions when two flange or draft surfaces meet. The flanges are extended and trimmed to their intersection so they join properly at corners. You can choose to Trim or Trim Convert the flanges.
Reverses the direction of the new surface(s).
Turn on this option if you want to specify the exact degree and maximum number of spans in the new surface(s).
Degree of the new surface(s) in the U direction. Enter a whole number from 2 to 9. This option only appears if Explicit Control is checked.
Degree of the new surface(s) in the V direction. (The surfaces are always of degree 1 in the V direction.)This option only appears if Explicit Control is checked.
If Surface Type is set to Multiple surfaces, this value specifies the maximum number of spans for each draft surface. If Surface Type is set to Single surface, it specifies the maximum number of spans for each piece of the original surfaces.
This option only appears if Explicit Control is checked, and Bézier Surfaces is not checked.
NURBS – Fits with a non-rational NURBS curve.
Bezier – Fits with a non-rational NURBS curve, then detaches at the spans to produce Bezier segments.
Surface UV – Follows the U or V parameterization of the underlying surface. If this fails, then the COS is fit using the Curvature method.
Chordal – Fits based on the arc length. Each parameter step corresponds to an equivalent step in 3D. If the Segmentation Option is Bezier, Alias tries to produce equally spaced CVs.
Parameter – Matches the parameterization of the COS.
Curvature – Fits based on the arc length and curvature. Places more CVs in areas of higher curvature.
Blend – A hybrid of the Surface UV and Chordal fitting methods. A UV to Chordal Influence value of 0 is equivalent to using the Surface UV method. A value of 1 is equivalent to using the Chordal method. For values in between, the point distribution is a geometric mean between the two types.
These options only apply when Type is set to Draft.
Select one of these to specify a pull direction along that axis.
Select this option to specify a pull direction normal to the current view. The vector is not drawn in the view windows.
If the current view is changed, click Refresh View Vector to update the vector.
Selecting this option lets you specify the name of an existing vector in the Picked Vector field, or pick the vector in the view. This vector defines the pull direction.
This button only appears if View is selected. Click it to update the vector if the view has been modified.
Click this button to create a vector construction object in the view windows. Unless you do this, the vector direction you specified is used by the tool, but you will not see and be able to re-use the vector.
Click in the view to place the start of the axis, or type the position and press . Use the vector manipulator to position the vector and click Accept.
When Type is set to Draft in the control window, and Draft Vector Options is set to X, Y, or Z, the tool uses the X, Y, and Z axes from the construction plane, if one is set.
The following rules apply:
When this option is checked on, Start and End sliders appear in the control window, and arrow manipulators appear on the draft surfaces. Drag these arrows to modify the extent of the draft surfaces across the input curves.
When this option is checked off, the draft surfaces extend to the ends of the input curves.
Range of draft surface (in orange) extends from 0.25 (Start) to 0.75 (End).
If you choose Single surface, a single surface is built. If you choose Multiple surfaces, a separate surface is created for each of the input curves you selected, and the surfaces are grouped.
Creating a single surface might add additional spans.
This option only appears if Surface Type is set to Multiple surfaces. If it is checked on, each surface will be a Bézier patch.
Bézier patches have a single span, and their maximum degree in the U direction is set through the Explicit Control section. The default is the degree of the input curve.
These options let you choose what types of curves are selectable as input. This is especially useful when using box selection.
Check this option to make free curves selectable as input.
This option only appears when Type is set to Draft.
Turn on this option to have the new surface automatically re-calculated and displayed as you modify the option values or make adjustments to the manipulators.
If it is off, you must click the Update button in the lower right corner of the window to update the surface(s).
If Auto Update is turned off, you can also use the spacebar to click the Update button.
Checking on this option displays continuity locators between the output surfaces, indicating whether or not they are tangent continuous. Green T locators indicate that the surfaces are tangent continuous while red/yellow T locators indicate they are not.
The Continuity Angle fromPreferences > Construction Options is used when testing for tangent continuity, and a shared boundary is only checked if it doesn't present any gap larger than the Topology Distance tolerance (also found in Construction Options).
Only natural (non-trimmed) edges are checked.
Turn on this option to check for positional continuity between the newly created surface(s) and the original surface(s). A green P means positional continuity exists.
If this box is checked, selecting a surface curve also selects all other surface curves that are tangent continuous with it.