Hi everyone. This is an alternative solution to modelling a car, using both NURBS and subdivisions.
It started life with a blueprint. I should mention to first-time car modellers that most images you find on the internet (such as the one I used) are not actual blueprints, but rather simple illustrations that are not accurate at all. You'll have to trust your eye on additional real car photos and even then perspective distortion can make an object look very different from reality. So gather lots of material from every possible angle to study the surface shapes.
I started by cropping each of the 4 images, engaging only the body and excluding the wheels. After the last image is cropped, you'll be left with slightly different dimensions in all images. I decided to keep the side image's length and height and the top image's width and resize the rest of the images. An additional step is to
rotate the top view 90 degrees counter-clockwise. This will help with placement inside MOI.
Now write down these 3 dimensions, fire up MOI and create a box with these exact dimensions, centered at the origin. Be sure to uncheck the "Maintain proportions" checkbox. This box is probably going to be huge, so scale it down by what factor you feel comfortable with so that it fits inside the grid.
Import the 4 images and align them to the box as pictured. Choose "Show in ortho only" and put in some transparency to help your curves stand out.
Next it's time to start creating some curves. The following screenshot may look like a spider's web, but is actually simpler than it seems. Some curves were used to create the actual surfaces, some were used for trimming and some were just helper curves to help visualize the volume. Also, some additional curves were created to make extended surfaces and were then discarded when those surfaces were finally trimmed.
The trick has been told for years in this forum (and I'm guilty of not following every time) that it's better to make an extended surface and then trim it. The hood of this car was done this way.
Other simpler surfaces were made by directly drawing curves at the surface boundaries. The network command was used for almost the whole model. Here's what it looked like when all panels were created, along with some trim curves that were later used in Modo to locate the various car elements. I should mention that I did almost each panel separately, with the exception of the front fender and door, which have a physical flow. This way there's no need to do cuts between the panels later.
At this point, I now regret not giving attention to some details. I left out some parts un-modeled and didn't tweak some surfaces which were obviously wrong, thinking that I would model them better in Modo. It actually made my life harder, because while the re-topology process was a walk in the park, the rest of the stuff took some serious time to do! In the end I re-did some parts again in MOI, like the door handle, headlights assembly, mirror and the gas door.
I then exported a fairly dense mesh to Modo with these settings.
Inside Modo the topology tools are like painting polygons over the underlying mesh. It's that easy! It was only the surfaces that I didn't took care of that needed to be tweaked. To better describe this workflow, it's like having a 3D blueprint which if it was done right, you can follow it with your eyes closed.
Half of the panels done.
After some sweat it was finally finished.
At that point I added some further details like the badges, tweaked some vertices and started the rendering process in keyshot. Overall it's a descent process that combines all goods of NURBS and subdivision modelling, but I now feel confident that staying all inside MOI would be even better. I slowly starting to think that there isn't a thing that can't be modeled in MOI just as easy as in polygons and I actually prefer the accuracy and control of NURBS.
Sorry for the long text, I thought I'd share all my thoughts thinking that should help a beginner decide if this workflow worth.
