NX7.5: XForm Rocks My Socks

Correction: I’ve been referring to the “WCS” as the “World Coordinate System,” and Mark Lawry was kind enough to point out my mistake: “WCS” stands for “Working Coordinate System.” As the WCS is dynamic, it shouldn’t be used to define parametric features. In other words, it’s probably find for rapid freeform modeling, but should be avoided when creating complex associative models.

Okay, today I want to show you one of the sickest things to hit solid modeling in a long, long time, and it?s only in NX 7.5. It?s called XForm, and it?s the best freeform-face deformation tool I?ve seen to date. Here?s why.

I?m going to hit [X] on the keyboard to activate the Extrude tool, and then click the XY plane to start a sketch there. I?ll then hit the [R] key to activate the Rectangle tool, and select the Center Rectangle from the dialog rail. Click to define three points, then Right-Click > Finish Sketch. The Extrude will fire off, we set a Distance, and hit the Middle-Mouse to drop the tool.

Not impressed yet? Oh, you just wait! And make sure you?re sitting down, lest you should faint and drop your grape juice on the carpet: Lets go to Menubar > Start menu > Shape Studio.

In shape studio, the [X] key has a different function: it stand for X-Form, which can also be accessed in the Toolbars > Shape Studio toolbar, or under menubar > Edit > Surface > XForm.

I?m going to just hit [X], and then select the top face of my rectangle. In the Parameterization tab, set the U and V degree values to 3, and make sure that the ?Deselect Poles Automatically? box is checked, and the ?Move? method is set to World Working Coordinate System. Select the Z-axis, and then head out to the viewport and drag any point. You can also drag edges to move entire rows of points all at once. [ctrl]+click multiple points to multi-select, and [shift]+click points to deselect. You can also box-select multiple points, just be aware that with multi-selections, you have to explicitly deselect the points with the [shift] key before trying to move anything else.

When we?re happy with the basic shape, we can middle-click to drop the tool. Okay, that?s kinda cool, right? Other tools let you modify faces, but not with a real control cage! Anyone who?s ever used SolidWorks? completely unusable ?Freeform? face deformation knows exactly what I?m talking about: this is fantastic.

But the goodness doesn?t stop there! Hit [X] again, and this time select the front face. Set the U degree to 2, and click the little blue X axis arrow in the viewport to define the Move direction, click the front edge, and drag it out a bit. Middle-click to finish, and hit [X] yet again. Select one side of the object, and set the V degree to five, and set the Move axis to Y. Select the line at the end of the face, and drag it all the way across, this time eating straight through the back face. That?s right: we can even completely eliminate unwanted faces with XForm. Really great. Pull a couple of the other edges closer along the X axis to adjust the curve. Set the U degree to 2, and drag a few of the bottom points in along the Y, and middle-click to drop the tool. Beautiful.

Hit [X] one more time and select the remaining face. Move the front and back edges in along the Y, and the top edge out a bit. Middle-click to drop the tool.

Now we?ve got a basic shape, but changing it is really easy. Right-click any face and select ?Edit Parameters.? Now you can simply edit the deformation right in place, without dealing with rollback. This even applies if we add an edge blend. I?ll hit the [alt] key to bring up my toolbar, select Edge Blend, and apply it to a minor edge. I can then right-click the front face, Edit Parameters, change the V degree to 2, and drag the bottom edge in along the X. Viola.

I can also add a simple conic Face Blend by hitting [alt], dropping down the Edge Blend icon and selecting ?Face Blend.? I don?t really want to get the entire ?chain? of tangent faces here, so I?ll right click the front face, and change the selection intent manager from ?Tangent Faces? to ?Single Face.? Select the front face, middle-click, the side face, middle-click, set the Shape to Conic, and the rest of the values however I see fit. Middle-click, and we?re done.

But what if I want a really baby-butt smooth curvature-continuous controlled blend? Fear not, babies, NX has you covered there too. First, hit [alt] and select the Line tool. Mouse-over the origin and wait a second, then click and select the origin. Now mouse over the Z axis, wait a second, and click. Choose the Z-Axis. Now drag the yellow arrow and ball icons to extend the line out in both directions.

Hit [alt], mouse over the Curve from Curves tools, and choose ?Project Curve.? Choose the line, middle-click, choose the side face, middle-click, choose the Y axis vector, and middle-click, then do it all over again, this time on the X axis. Keep in mind that you may have to ?Reverse? the direction.

Now hit the [alt] key and run a command called ?soft blend?. This is one of NX?s older tools, so its UI is a little different from the others, but it?s still easy enough to use. The beauty of the Soft Blend is that it takes advantage of NX?s powerful and stable Sweep code, making Soft Blend features incredibly robust. Right click and make sure that the selection intent is set to ?Single Face,? then select the first face, middle-mouse, check the selection intent again, then select the second face, middle-mouse, the first project curve, middle mouse, the second project curve, middle-mouse, click ?Define Spine String? and select the center sketch, middle-mouse, select Smoothness > Match Curvature, set the Rho value to .5, and middle-mouse to confirm.

Select all the curves and hide them using [ctrl]+[B] (for ?Blank?), and in the ?Analyze Shape? toolbar, select ?Face Analysis ? Reflection.? Set the line thickness to ?Normal,? the Display Surface Resolution to ?Super Fine,? select the blend and its adjacent faces, then click ?Apply.? The Zebra stripes will be beautifully smooth across the surface transitions. Click ?OK? to drop the tool, and then hold the Right-mouse in the viewport and drag it UP to go back to normal shaded mode.

Don?t forget we can always right-click any of our XFormed faces and select ?Edit Parameters? to nudge it around any way we like. The blends will update perfectly, and life with NX is good.