This section describes the controls that are common to Point and CV surfaces. A rollout labeled Surface Common contains the surface sub-object controls for NURBS surfaces.
The selection controls and other common controls are described in the previous section, "Common Sub-Object Controls."
You can delete surface sub-objects by clicking this button.
Converts the surface sub-object to a (dependent) U Loft surface. Can also change the dimension used to construct a U Loft surface.
Tip: Make loft creates a loft with uniformly spaced curves. To make a loft with adaptively spaced iso curves, manually create the curves and then loft them with U Loft or V Loft.
When you click Make Loft, a Make Loft dialog appears, with these controls:
From U Iso Lines: Use curves along the surface’s U dimension to construct the loft.
From V Iso Lines: Use curves along the surface’s V dimension to construct the loft. If the surface was a U Loft to begin with, set this to change the lofting dimension.
Number of Curves: The number of curves used by the loft. Curves are distributed evenly along the appropriate dimension.
Preview: When set, displays a preview of the new loft surface. Clearing this toggle can speed up loft creation.
Delete Original Loft Curves: This is enabled only if the surface was a U Loft to begin with. If set, Make Loft deletes the original loft curves when you click OK. If cleared, the original curves remain where they are. Default = cleared.
Note: You can't use Make Loft if the surface sub-object is in an error condition.
These are the controls that affect how the surface sub-object appears when you render it with the renderer. They don’t affect how the surface appears in shaded viewports.
Renderable: When turned on, the surface renders. Turn off to make the surface invisible in renderings. Default = On.
Display Normals: When turned on, 3DS MAX displays the normal for each surface selected There is one normal per surface sub-object. The normal is displayed at the surface’s UV origin, so displaying normals can help you see how materials will be mapped. On the other hand, the normal can be hard to see if you are zoomed out.
Flip Normals: Turn on to reverse the direction of the surface normals.
Tip: The Flip Normals control is useful for viewing a surface that is mostly concave or mostly convex. With more complicated NURBS surfaces, you often want to render both sides of the surface. Turn on Force 2-Sided in the Render Scene dialog to see both sides of the surface. To see both sides of the surfaces in viewports, turn on Force 2-Sided in the Rendering Method panel of the Viewport Configuration dialog.
The controls in this area support materials, including tiling and positioning mapping coordinates on the surface.
Material ID: Use this to change the surface’s material ID number. Multiple material IDs in a single NURBS object let you assign a Multi/Sub-Object material to the NURBS object.
Channel: The radio buttons select the UV coordinates channel, either 1 or 2. Default = 1.
Generate Mapping Coordinates: Generates mapping coordinates so you can apply mapped materials to the surface. Each surface in a NURBS object has its own set of mapping coordinates.
U and V Offset: Offsets mapping coordinates along the surface’s local U axis or V axis. That is, at 0.0 (the default), the map begins at the U or V origin. Increasing an Offset value moves the map forwards along that axis, and decreasing it moves it backwards. These parameters are animatable.
U and V Tiling: Control the tiling of UV mapping coordinatesthat is, the number of time a mapped material’s map is repeated in the surface’s local U axis or V axis. Default = 1.0 for both axes (no tiling). These parameters are animatable.
The buttons Break Row, Break Col., or Break Both let you break a surface into two or four independent surfaces.
Break Row: Breaks the surface into two in the direction of a row (the surface’s U axis).
Break Col.: Breaks the surface into two in the direction of a column (the surface’s V axis).
Break Both: Breaks the surface into four in both directions.
Note: If you break a dependent surface the new, "broken" surfaces are all made independent.
Extends the surface by changing its length.
Caution: Extending a surface loses all animation controllers for the surface and its points or CVs.
The surface extension is invalid and will disappear if it would cause the surface to intersect itself or if the edge of the surface touches itself but is not closed. For example, you can't extend the top of a cylinder.
Joins two surface sub-objects together. This operation is similar to creating a blend surface, but the new area becomes part of the surface object, not a dependent sub-object.
Caution: When you join two surface sub-objects, you lose the animation controllers for all point or CVs on both surfaces.
Tolerance: A distance in 3DS MAX units. If the gap between the surfaces you are joining is greater than this value, 3DS MAX creates the join by first creating a blend surface. If the gap is less than this value, or if the surfaces are overlapping or coincident, 3DS MAX doesn’t create the blend.
Creating a blend and then joining the three surfaces into a single surface is the better technique. The result matches the parent surfaces well. Without the blend step, the resulting surface can deviate from the parent surfaces, in order to maintain smoothness. (The amount of deviation depends on how far from tangent the two input curves or surfaces were at the join.)
A problem arises when there is a gap but it is too small. In this case, 3DS MAX generates the blend but because there isn’t enough room for it, the resulting surface has a loop in it. To avoid this loop, set the Tolerance higher than the gap distance.
If you set the tolerance to 0.0, 3DS MAX chooses a value to use for the Tolerance.
The close controls let you close a surface. They appear on the Point Surface or CV Surface rollout while an independent surface sub-object is selected. They have no effect if the surface is already closed in that direction.
Close Rows: Closes the surface by joining the ends of its rows.
Close Cols.: Closes the surface by joining the ends of its columns.
Keyboard shortcut: DEL
One or two blue curves appear on the surface to indicate where the break will occur.
3DS MAX joins the two original surfaces, creating a single surface that replaces the two original surfaces. (Unlike a blend, the portion between the two original surfaces is part of the new surface, not a dependent surface sub-object.)