Lærdal Medical - Workshop
Freeform Exercises - Review for Industrial Designers
This exercise is simply meant for you to play around with the very basics of NX. This includes functionalities and tools such as creating a part file, sketching, extrude, emboss etc.
An important giveaway for those of you who is new to NX: There is no correct way of modeling, but rather a collection of best practices. This video gives merely one way of achieving a desired form/geometry, but there is plenty of other ways to achieve the same form.
With that said, just keep one rule of thumb in mind: A short history tree is a good history tree. Mark Twain once said: “I didn’t have time to write a short letter, so I wrote a long one instead.”. This can actually be transferred to parametric modeling. A short history tree makes for excellent parametric models, as the geometry more easily can be changed at later stages.
This exercise shows the utilization of the tools Bounded Plane and Fill Surface.
The giveaways from this exercise is that you should use bounded plane for generating planar surfaces, both to verify that you actually are working with planar geometry, and also to potentially utilize the flat surfaces for further geometry editing (e.g. drawing sketches directly on surface).
Fill Surface is an excellent (almost magical), robust and flexible tool, which not only can be used to fill gaps in your geometry, but also to construct geometry from splines and help geometry. Remember to select edges (and not splines/curves) on your help geometry in order to inherit G1 or G2 continuity.
Exercise 3 – X-FORM
This exercise has a focus on utilizing X-form in combination with traditional freeform tools (splines and surface meshes). X-form is very robust and flexible visual shaping tool, but keep in mind that it is a freeform editing tool, meaning that you have to have a geometry to start with. This could either be a primitive, such as as a block or cylinder, but it could also be more advanced, as illustrated in the shorter second video.
The second video here merely demonstrates how to edit more advanced shapes, while maintaining existing G1/G2 continuity.
Warning: Be cautious if you want to utilize X-form to clean up your surface poles by lowering surface degree, as you may end up losing your G0-continuity.
Exercise 4 (only if time)
This exercises shows when you may have to increase your spline degrees in order to sucessfully utilize G-continuity with Studio Surface. Remember that a higher degree of G-continuity means a higher order of derivative. To elaborate, a G2-continuous transition for two spline requires a minimum of 3rd degree splines, such that the second derivative of the continuing spline doesn’t end up being the value of nothing.
As the video demonstrates, when constructing the first studio surface, we get a error stating G0-continuity cannot be preserved. This can be solved either by increasing degree of splines, or changing alignment from Parameter to Arc Length.
Exercise 5 & 6 –
NX Realize Shape
If you haven’t already, it is strongly recommended that you take a look at the introduction course to NX Realize Shape before reviewing these two videos. The first video here shows an alternate shaping workflow, as well as some tips on dividing and connecting surfaces with sweep functionality.
Click here to download the starting point for this exercise and try for yourself.
As NX Realize Shape is primarily a visual sculpting tool, it may be necessary to get accurate dimensions for the geometry itself. The second video here shows how you can utilize optimization capabilities to achieve this.
Keep in mind that this tutorial is suited for ADVANCED users.
You can download the starting point here if you want to test this out yourself.