Category
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New Users
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Time Required
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15 minutes |
Tutorial File Used
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vacuum_start.wire (created in the Set up the scene lesson)
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In this lesson you lay out the basic volume and shape of the vacuum to start this process for the project. This lesson also
introduces basic interaction and organization skills.
Objectives
- Create and modify an initial volume
- Pick and transform control vertices
- Create and modify basic curves
Prerequisites
- You have completed the Set up the scene lesson.
Watch video
Before you begin
If your vacuum_start.wire file is not currently open, use the menu item to open it, or the menu, if the file is one of the last ten files opened.
The three reference images should be clearly displayed.
Create and place the motor box volume
The first step in creating the vacuum is to visualize the enclosure for the motor and removable waste can. This will not be
a final object, but placing a temporary object in the scene can assist in laying out other elements of the design. This also
introduces transforms and pivots, as well as components and control-vertices of objects.
- Create a layer with . Double-click the layer name and rename the layer motorbox. This also makes the new layer the active layer. All objects are created on this layer until another layer is selected.
- On the Surface tab of the Palette, click and hold on the geometric primitive icon. The Primitives tools subpalette displays
even after you release the mouse button.
- Hover the mouse over the icons to see their tooltip names. Click the tool to start the Cylinder creation process.
- Click-drag near the center of the Back view. A new cylinder is oriented to this view. You can reposition it as long as the mouse button is held down.
While still dragging the new cylinder around the view, press the key to snap its centerpoint to the grid. Release the mouse button when the cylinder is near the center of the motor box in
the sketch.
The new cylinder remains selected and the creation handles are still displayed. These handles allow easy translation, rotation,
and scaling of the new object.
The arrow handles can be clicked and dragged to translate the object. The box handles allow non-proportional scaling. The
dotted arcs and the sphere handles allow rotation along each axis.
- In the Left view, use the red (X axis) arrow handle to the cylinder to the center of the motor box area, then use the red box handle to non-proportionally the cylinder along the X axis to match the sketch.
Adjust the shape of the motor box with CV edits
You can modify the shape of objects in Alias with specialized tools or object parameters, or by manipulating control vertices (CVs). The simplest method to match the
volume of the sketched motor box is to taper the cylinder by manipulating its CVs.
Use the Pick Object tool to select the cylinder if it is not already picked.
- In the Control Panel, either in the Default or Modeling workflow, expand the subsection and check the display on.
The control vertices for the three component surfaces of the cylinder display. The actual CVs are shown as yellow Xs above
the surface they affect, with Hull lines shown between consecutive CVs in orange, indicating that the displayed CVs are all
selected.
- to deselect these items, and the CVs and hulls display in dark red.
- Bring up the Pick marking menu ( + + ) and choose the tool.
- Pick the body of the cylinder. Notice that the end caps are not selected. The tool in the marking menu is an example of the tool with its options modified so that only surfaces can be picked.
The Cylinder body has four rows of CVs going down its length (the V direction). By default, the primitive tool creates degree 3 surfaces, which require at least 4 CVs in each direction (the Cylinder has 8 CVs going around
its circumference, or the U direction.).
- In the Control Panel, change the numeric value for the in the second entry box (corresponding to the V direction) to .
The new parameter is previewed in the workspace windows, where only two rows of CVs are now shown.
- Click in your active viewport to commit the changes to the Cylinder body surface parameters.
- to deselect the modified surface, then choose the tool.
- In the Left view, drag a pick box around the CVs visible on the left side (where the taper should occur).
CVs from both the cylinder body and the cap surface are now picked, which is important to keep the edges of the cap and cylinder
body lined up. The tool works on all visible CVs in the scene.
- Choose the tool, and in the Left view, click and drag with the . The selected CVs scale toward the object pivot (the green box currently at the center of the cylinder), and the Cylinder
both tapers and becomes shorter.
- While the tool is still active, click and drag in the Left view with the . This constrains the scale to the X axis, which lengthens the cylinder again, but now we know what the object pivot does.
- Choose the tool, and in the Left view, click and drag with the to constrain the movement to the Y axis, and move down the selected CVs until the surface edge (the white wireframe) rests
on the X axis origin line again.
Fine tune the shape
As seen in the Back view, the cylinder is too narrow for the sketch, but you can make these modifications to the whole object.
- Choose from the Pick marking menu to deselect these CVs, then choose and pick the Cylinder.
For the next few scale operations, the object pivot should be on the bottom of the object and in the center.
- Choose the tool from the Palette, or from the Transform marking menu.
- In the left view, click and drag with the to constrain the pivot movement to the Z axis.
- While dragging with the , hold down the key to the pivot to the bottom edge of the surface (the white wireframe).
- Choose the tool.
- In the Back view, click-drag with the to constrain the scaling to the Z axis until the height of the cylinder matches the sketch, and then click and drag with
the to constrain the scale to the Y axis until the width of the cylinder matches the sketch (approximately).
NoteThe non-proportional scale came from the center and bottom of the object, where the object pivot was placed.
- Choose the menu item to view the volume in the scene.
In the Left view, there is a slight arc to the top of the motor box volume. The surface parameters and CVs can be adjusted to add this
arc.
- , then choose and select the cylinder body.
- In the Control Panel, change the numeric value for the in the second entry box (corresponding to the V direction) back to .
You can create the arc to the top with the two extra rows of CVs and increased degree of the surface parameter.
- , then choose . In the Left view, drag a pick box around the top rows of CVs in the cylinder body to select 6 CVs along the top center of the surface.
- Choose and click with the in the Left view to add some arch to the top of the surface.
- Use to select the entire cylinder, then uncheck the Control Panel visibility toggle to hide these elements.
This small part of the overall vacuum is set up. You will add more features and surfaces, but this volume can be used as reference
for the rest of the process.
Draw the front profile
- Create a layer with , and make it the active layer.
- Double-click the new layer and rename it to topcurves to keep the curves organized for the next object.
- Expand the Perspective view to fill the viewport.
- Click the face of the ViewCube to switch to the Front view.
The ViewCube remains visible in these orthographic views that are accessed by clicking on a face of the ViewCube. (Proper
orthographic viewing requires the ViewCube to be set to .)
If needed, use the ++ (Windows) or ++ (Mac) navigation shortcut to Zoom until the sketch fills the view again.
- From the Curves tab of the Palette, choose the tool.
- Click to place 4 new CVs, from left to right, across the top of the sketch close to what is shown in the following image.
When you place the fourth CV, the curve appears in white.
(By default, the tool creates degree 3 curves, which require at least 4 CVs to define the shape).
- While the last CV is still selected, choose the tool from the bottom of the Control Panel in the Default workspace. This tool allows quick picking and movement of CVs and Hulls in the workspace.
- Click-drag each CV to move them so the curve follows the shape of the top surface and extends beyond the edge of the canvas.
- With the tool still active, pick the CV nearest to the middle of the sketch (a red square) and hold down the key (Windows), or the (Mac) to snap to the grid, and click-drag with the to constrain the movement to the Y axis
The CV easily snaps to the darker origin line without moving to a grid intersection.
Draw side profiles with edit points
- Hover the mouse cursor over the ViewCube to show the face arrows. These arrows allow quick access to adjacent orthographic
directions.
- Click the face arrow at the right of the cube, which rotates the orthographic view to the Left.
The first profile curve arcs across the top of the handle from the front to the middle. This curve should intersect the first
CV of the previous curve.
- Use the ++ (Windows), or ++ (Mac) navigation shortcut to Zoom and ++ (Windows) or ++ (Mac) to Pan until the sketch fills the view again.
- Right-click on the tab of the tool Palette to show the text menu of curve tools. Choose .
You create Edit Point curves by placing points that the curve will pass through. The CVs of the curve are placed automatically,
and the curve appears after you place the second edit point.
- Hold the key and click with the to grid snap the initial edit point at the front edge.
- -click and drag to place the second point along the front edge in the sketch, then hold the key down to magnet snap the third edit point to the initial CV of the previous curve (represented by a red box).
- to end curve creation, however the tool is still active.
Use this tool persistence to create the back half curve.
- Magnet snap the first point to the top center point of the other curves.
- -click and drag two more edit points to the back of the sketch to define the back curve at the top edge.
- Click-drag on the ViewCube to examine your curves in perspective and insure they intersect.
- Switch to the Top view.
- Choose the tool.
- Hold down the (Windows) or (Mac) key to activate grid snap, and click to place 5 new CVs along the bottom profile in the sketch, as shown in the following image.
- When finished, to end the curve.
- and drag-select the third and fourth CVs.
- these two CVs so the curve matches the sketch as shown in the following image.
IMAGE: create_movecv2.png
- Choose to save your file with the new name vacuum_part2.wire in the project folder, rather than overwriting the initial vacuum_start.wire file of the scene.
Now that , Objects, Curves, CVs and basic picking and transformations are familiar, you can create more advanced surfaces
in the Create and evaluate surfaces section.