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Archive for October 5th, 2009

The weekend seemed very short and I apologize for not putting this up earlier, like I said I would, but I wanted to spend time with my husband, who had just come back from a long trip to Japan, and celebrate both our birthdays while he was here for a couple of days before he had to go back to Japan for a trade show.  Every year is the same: he’s travelling during the week of his birthday, by the end of September, and again during mine, the first week of October. It never fails! But I don’t complain, because God has blessed our family by giving him a great job, and that’s plenty.

Anyway…  Transforming the plain round head of the funkey into a mouse’s head began by changing the sketch for the revolved surface from an arc (spherical head) to a partial ellipse (oval shaped head).  I also changed the axis of revolution, just tilted it up a bit.

Next step was to modify the ears. Instead of revolving the sketch 360 degrees as before, I only revolved it 180 degrees and then thickened the surface to a solid, by using the command Thicken, then mirrored the ear with respect to the Front plane and filleted the edges.

On the Top plane I made a sketch to aid me in the process of shaping the mouse’s snout. I used the sketch to trim the face’s surface with it. In the image, you can see the surface I’m removing in purple and the sketch appears in blue on the Top plane. Notice that there is a projection of this sketch on the back of the head, but I didn’t select that surface to be removed as well.

After trimming the surface, I patched the hole with a new surface using Fill Surface.  I didn’t really want to just patch the hole; I wanted this surface to have a more pronounced shape, different to that of the face. My goal was to create the nose of the mouse, so I thought if I added a point as a constraint curve (the one you see in the image), the new surface would have to pass by that point and I’d be able to shape it that way into a mouse’s snout. Well, the idea was good in part, but you can’t really depart that much from the original shape by using this method, or else the Fill Surface will fail. This is as far as I was able to locate that point.  I get a bump in the surface, but not so much for a mouse’s nose.

And this is where I decided to try my luck with the Freeform tool.  By the way, before you read any further, I would like you to take a look at a very nice video that Mark Biasotti shared with all the community through the SolidWorks Discussion Forums. You can find the video at: http://files.solidworks.com/special-videos/freeform demo.zip  This video explains in more detail how to use the Freeform tool.

Did you check out the video? Great! Now I’ll tell you how I used Freeform with my mouse.  First of all, I established that the boundary conditions at the edges would be Contact. Why? Well, because I wanted to deform that surface considerably and I knew the result would certainly not be tangent or have the same curvature of the face, but that was OK with me. For your own projects, however, you may want to keep the edges tangent or have the same curvature, so keep an eye on that.  I also established that the deformation would be symmetrical with respect to the Front plane by choosing Direction 1 Symmetry. What this means is that whatever I do to one side of the surface will automatically be done to the other side, thus making my work easier.  Notice the plane of symmetry in the middle of the nose. In this particular case, the plane is coincident with the Front plane of the model.

Next, I added a few curves (they appear in green in the image) by clicking on Add Curves and placing them pretty much wherever I thought I needed them.  On most of these curves, I also placed a few points, by clicking on Add Points and placing them over the curves I had just added previously. Each one of these points would allow me to push and pull from it, thus deforming the surface. Pulling a point in one of these curves will affect the appearance of the rest of the surface, at least up to the next curve. It sounds complicated, but each one of the points also has a Triad that gives you some control over the whole deformation process. You can either pull directly on the screen or enter numerical values for each axis direction in the property manager.

While you are at it, if you take a closer look at the edges of the surface being deformed, you’ll notice some arrows/vectors. If you click on them, a Triad will show up and by manipulating this Triad you’ll be able to adjust the tangency and vector direction of the surface right at the edges.  This will also affect the look of the rest of the surface.

So, basically, this is what I did with Freeform. I spent a few minutes pushing and pulling, adding and removing points. Just dynamically changing the surface until it looked the way I wanted it. I wasn’t really worried about creating the best of surfaces at this point, or if the mouse would be able to be manufactured or not; I just wanted the looks. Nevertheless, with some effort and perhaps a sketch or two to guide the deformation, I believe better results can be achieved with this tool.

Moving on with the rest of the mouth. Before deforming the surface, I had made an offset copy of it to serve as the back of the mouse’s mouth, by using the Offset Surface tool, as you see here.

Then, once the surface had been deformed, I trimmed it again using another sketch I made, again on the Top plane. This sketch will help me shape the smiling mouth. You can see the sketch in blue and the purple area is the surface to keep.

Once I had the gap for the mouth, I opened a 3D sketch and placed a two-point spline from corner to corner, like you see here.

I used this 3D sketch to create a couple of surfaces using Fill Surface. This is one of them.

And this is the other one.

Notice that the surfaces intersect the one for the back of the mouth that was previously created using Offset surface.  It’s time for some trimming.

First, I trimmed both new surfaces against the one I had created for the back of the mouth. In the image you see the parts in purple are the areas to keep and the surface in black is the one for the back of the mouth, used as the trimming tool.

I trimmed the back of mouth surface against the other two in a very similar way and then knitted all three surfaces together.

The eyes were made in a very similar way to the mouth. First, using a sketch to trim part of the surface of the face…  The sketch appears in blue and the area in purple is the one being removed.

I then opened a 3D sketch, converted the edge of the snout, thus creating a spline, and trimmed the spline  to the edges of the eye hole, like you see here. This sketch will be used to loft a surface for the eye.

This is the loft for the eye. As you see here, the lofted surface was created between the edge of the eye hole and the 3D sketch. I added a start constraint using the Top plane to define Direction Vector. I just wanted to give the eye some volume and make it look like it was popping out of the face.

The rest of the features for the face are fairly simple. The black little nose was made using a surface revolve and the teeth are just a couple of extrusions.

I’m still fascinated by the Freeform tool, however. I want to explore it further and see what else it can do and what other applications it can have, but most importantly, learn to control it a lot better than this in order to achieve the best results possible.