MCAD Tech News #116

3 Mar, 2004 By: Joe Greco

This issue sponsored by CFDRC/ESI Group.
One Step Closer to Virtual Prototyping

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Last week, in my coverage of the NDES 2004 event (http://www.cadalyst. com/cadalyst/article/articleDetail.jsp?id=86883), I briefly talked about the demonstration I received of Pro/ENGINEER Wildfire 2.0. Since then, a number of you contacted me wanting to know more details about the upgrade, in particular how the new enhancements to Wildfire's Warp tool compare with similar tools found in competing products such as SolidWorks. So I figured I would take a closer look at the Warp tool enhancements as well as other Wildfire modeling improvements.

This issue sponsored by Autodesk.

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One of the most exciting features in Wildfire 1.0 was a completely new command called Warp, which allows users to deform 3D models for the purpose of creating sculpted shapes like those found in today's consumer products. Wildfire 2.0's Warp command includes two new commands that PTC calls Spine and Sculpt. These add to the program's existing options: Transform, Stretch, Bend, Twist, and Warp (Warp is a little confusing-PTC should have called this option Deform or something else when they decided to name the command Warp). 

For starters, the Spine option lets you select a predrawn curve and then uses that curve to determine how the shape deforms. Both SolidWorks with its Deform Tool and thinkdesign with its Global Shape Modeling (GSM) employ a similar option for sculpting shapes. However, their deformations are more exact-you select a specific edge of an object as the "origin" curve, and it deforms precisely to the selected "target" curve. In Wildfire, an edge can't be selected-only one of the three standard planes can be used. The result: the final shapes generated are interesting enough to inspire your creative juices, but it's a little difficult to predict the exact result ahead of time. Fortunately, the model updates quickly, so if the result isn't the one you want, it's easy to tweak. Do this by editing the shape of the target curve by dragging its points, a capability the other programs don't offer. 

The second new Warp tool, Sculpt, also offers some powerful options. When you start it, you select a plane, and then an editing mesh appears parallel to that plane. The density of this editing mesh can be changed from the default 3X3 to something higher if more detailed editing is required. Clicking a single button called Switch Orientation changes the position of this mesh. For instance, if it's lying on the top of the object, it's easy to reorient it so it lies on the front or bottom. Notice I didn't use the word face because the mesh doesn't map directly to a face-it lies on what would be considered one of the six standard orthographic view planes-top, bottom, left, right, front, or back. This means editing is not done directly on the object's face, a technique some users prefer. Despite this, the Sculpt tool is still very handy because of the many options available.

For instance, let's say the shape is a simple cube-like object and the mesh is edited while lying on the top of a model, thus deforming only that side. When the Switch Orientation button is selected, the editing mesh moves to the next orientation, and the same deformation is applied to that side. (If this is a little hard to follow, check out figures 1 and 2.)

Deformed top face.

Figure 1. The mesh was edited, thus deforming the top face. Note the red and green arrows—they are for sizing the mesh.

Deform again.

Figure 2. By clicking on the Switch Orientation button, you can apply the same deformation to another face.

Once again, as with the Spine option, the results of changing the mesh orientation can be unpredictable, but I think PTC's goal is to let users rapidly explore different options, some of which may not have been immediately obvious: "Hmmm, let's see what happens if I apply this edit to this face. . ."

Another interesting option is that when the editing mesh is set up to lie on the top of an object and one of its points is dragged, you can select a mirror option that symmetrically deforms the bottom of the model. 

When sculpting shapes using techniques like these, it is important to have control over the area that the deformation actually affects. SolidWorks and thinkdesign do this via the selection of edges and faces. For instance, in SolidWorks, you can set a selected face as fixed and then use the Weight slider to determine if that fixed face will influence only a small area or perhaps a larger area. This method works, but PTC takes a different approach in its Warp command. In Wildfire, a box is sized by dragging two arrows, and only things inside the box are affected by any changes. I like this method because it's a bit more visual and, unlike some of Wildfire's other approaches, a bit more predictable.

One aspect of the Warp tool that is not new, but worth noting, is that Wildfire builds a list of warp features that have been applied to a shape. This makes it easy to go back and delete one, change the order in which they were applied, or insert a new warp feature in the middle of a series of such operations. This also means a single Warp command can contain, for instance, Bend, Twist and Sculpt operations. In contrast, SolidWorks users must run their Deform tool three separate times to achieve similar results.

As reported in the previous issue, PTC updated the user interface of several modules such as sheet metal and assembly design to give them the Wildfire look and feel. I created some sheet-metal parts, and though access to the Wildfire Dashboard made the task of modeling a lot easier, the old-style Menu Manager still appears. In addition, creating sheet-metal parts wasn't as dynamic as in most other programs. For instance, you can drag to define only a few parameters such as the angle of a new flange or its bend size. The length of a flange can't be dragged. 

Another user interface change to a modeling tool appears in the Pattern command. I liked the way the software can easily create a staggered pattern, as well as with a single click remove any unwanted components.

In short, I like the new modeling additions in Wildfire 2.0. The fact that a program over 15 years old is still making modeling improvements shows that modeling is still an issue and enhancements are still needed to make users more productive. Look for a full review covering more of Wildfire 2.0 in an upcoming issue of Cadalyst.