Create panel >? (graphics) > NURBS curve >; Rollout bar; "CV curve" button
Default menu: create menu > NURBS”>" CV curve.
Alt menu: object menu > NURBS and patches >; "CV curve"
When creating a CV curve, you can create multiple CVs at the same location (or nearby locations), which will increase the influence of CVs in this curve area. Create two overlapping CVS to sharpen curvature. Create three overlapping CVS to create an angle on the curve. This technique can help shape the curve, and this effect will be lost if the CV is moved separately later. (you can also gain enhanced influence by merging multiple CVS. )
CV curve can be the basis of the whole NURBS model.
CV forms define the control lattice of curves.
Draw a three-dimensional curve
When creating a CV curve, you can draw a 3D curve. To this end, there are two methods to choose from:
Draw in all viewports: With this switch, you can draw curves in any viewport to draw them in three dimensions.
Drag CV with Ctrl key: When drawing curves, you can use Ctrl key to draw CV outside the construction plane.
Use the Ctrl key to move the mouse further to lift the latest CV out of the construction plane. To do this, there are two ways to use this key:
Click and drag. If you hold down Ctrl and mouse button, you can drag to change the height of CV. Set the position of CV when you release the mouse.
This method may be more intuitive.
Click. If you hold down Ctrl+ and click, and then release the mouse button, you will change the height as you drag the mouse. Click the mouse again to set the CV position.
This method reduces the damage caused by repeated pressure.
When offsetting CV, draw a red dotted line on the original CV of the construction plane and the actual CV of the offset plane. You can move the mouse to an inactive viewport. In this case, 3ds Max can set the height of CV using the Z axis of CV in the inactive viewport. This can make the set CV height more accurate.
When changing the CV height, you can still use snapping. For example, if you enable CV snapping, you can set the same CV height as other CVs by snapping CVs to other CVs in an inactive viewport.
process
To create a NURBS CV curve:
Go? Create a panel.
Activate? (Graph), and then select NURBS curve from the drop-down list.
Enable CV curves.
In the viewport, click and drag to create the first CV and the first curve segment. Release the mouse to add a second CV. You can add a new CV to the curve by clicking each subsequent position. Right-click to end curve creation.
Note: If you can start creating a curve by clicking without dragging, you can also create the first CV of the curve. If you release the mouse five pixels away from the first mouse press, this will create another CV.
When creating a CV curve, you can press the Backspace key to remove the last CV created, and then remove the last CV in the reverse order.
If Draw in All Viewports is on, you can draw and create 3D curves in any viewport.
To lift the CV out of the construction plane, use the Draw 3D Curve key, as described in the topic Drawing 3D Curves earlier.
As with spline curves, if you click the initial CV of the curve, the Close Curve dialog box is displayed. This dialog box asks if you want to close the curve. Click No to keep the curve open, and click Yes to close it. (You can also close curves when editing them at the Curve sub-object level. When the closed curve is displayed at the Curve sub-object level, the initial CV is displayed as a green circle, and the green marker indicates the direction of the curve.
Adjust curve creation parameters.
(Optional) To add a new NURBS curve sub-object, you can disable the Start New Drawing check box and repeat the above steps.
connect
The creation parameters of point curve and CV curve are the same.
"Rendering" rollout
Enable in renderer
When this option is enabled, the drawing will be rendered as a 3D mesh using the radial or rectangular parameters set for the renderer.
Enable in viewports
When this option is enabled, the graphics will be displayed as a 3D grid in the viewport using the radial or rectangular parameters set for the renderer.
Note: Nitrous does not support this display. If you want to view the 3D grid, you can switch to the old version of Direct3D or OpenGL driver.
Use viewport settings
Used to set different rendering parameters and display the mesh generated by viewport settings. This option is available only when Enable in Viewport is turned on.
Generate mapping coordinates
Enable this item to apply mapping coordinates. The default setting is disabled.
The u coordinate will surround the thickness of the spline once; The v coordinate will be mapped once along the length of the spline. Tiling is obtained by using the "Tiling" parameter of the material itself.
Real world map size
Controls the scaling method used by the texture map material applied to this object. The zoom value is controlled by the Use Real World Scale setting, which is located in the Coordinates rollout of the applied material. The default setting is enabled.
viewport
Turn on this option to specify radial or rectangular parameters for the drawing, which will be displayed in the viewport when Enable in Viewport is turned on.
come on
Turn this option on to specify the radial or rectangular parameters of the drawing, which will be displayed in the viewport after rendering or viewing when Enable in Viewport is turned on.
Radial; radiating
Displays a 3D mesh as a cylindrical object.
thickness
Specifies the diameter of the viewport or rendered spline mesh. The default setting is 1.0. The range is 0.0 to100,000,000.0.
Splines are rendered with the thickness of 1.0 and 5.0 respectively.
Edge number
Sets the number of edges (or faces) of the spline mesh in the viewport or renderer. For example, a value of 4 represents a square cross section.
corner
Adjust the rotational position of the cross section in the viewport or renderer. For example, if the cross section of a spline is square, you can use Angle to place the plane face down.
rectangle
Displays spline mesh graphics as rectangles.
aspect ratio
Sets the aspect ratio of the rectangular cross section. The Lock checkbox allows you to lock the aspect ratio. When Lock is turned on, the width is locked to the depth at a constant aspect ratio.
length
Specifies the cross-sectional dimension along the local y-axis.
width
Specifies the cross-sectional dimension along the local x-axis.
corner
Adjust the rotational position of the cross section in the viewport or renderer. For example, if you have a square cross-section, you can use Angle to locate the face-down plane.
Automatic smoothing
If Auto Smoothing is enabled, the spline curve is automatically smoothed by setting a threshold lower than the specified threshold. Automatic Smoothing Sets smoothing according to the angle between spline line segments. If the angle between them is less than the threshold angle, any two connected line segments can be placed in the same smoothing group.
threshold value
Specifies the threshold angle in degrees. If the angle between them is less than the threshold angle, any two connected spline segments can be placed in the same smoothing group.
Curves and the same curves rendered with thickness.
"Keyboard Input" rollout
Use the Keyboard Input rollout to create NURBS curves by input. Use the Tab key to move between controls on the rollout. To click a keyboard button, press Enter while the button is active.
X, y and z axes
Used to enter the coordinates of the next point to be added.
Add point
Add CV to the curve.
weight
Enter the weight of your resume.
close
Ends curve creation and creates a line segment between the last CV and the initial CV, thus making the curve a closed curve.
accomplish
End curve creation and keep its open terminal.
"Create CV Curve" rollout
This rollout contains controls with approximate curves.
Interpolation group
Use the controls in this group box to change the precision and the type of curve approximation commonly used to generate and display curves.
Draw in all viewports
When drawing a curve, you can use it in any viewport. This is a way to create a 3D curve. When this option is off, the curve is drawn in the viewport where the curve is drawn. The default value is enabled.
When Paint in All Viewports is on, you can also use snapping in any viewport.
"automatic reparameterization" group
Using the controls in this group box, you can specify automatic reparameterization. These controls are similar to those in the Re-Parameterization dialog box. In addition, all options except "None" can instruct 3ds Max to automatically reparameterize curves, that is, whenever editing by moving CV and thinning.
None will not be reparameterized automatically.
Chord length selection algorithm for re-parameterization.
Re-parameterization of chord length can set the kink space (in parameter space) according to the square root of the length of each curve segment.
Re-parameterization of chord length is usually the best choice.
Uniformly spaced junction.
The advantage of unified node vector is that you can only change the curve or surface locally when editing. If the other two forms of parameterization are used, moving any CV will change the whole sub-object.