Modeling a car - a quick run-through

I wrote this little instructional how-to at CGSociety on the topic of modeling a car in a poly-modeling fashion and thought it might be a good idea to make it a blog post. This question get's asked quite ofter - what is your modeling workflow like, so here's how I do it.

First step is to create a splinecage. This consists of setting up the blueprints and getting them aligned on all four planes - side, top, front and back. Then it's just a matter of creating splines where the edges run on the car. For the body panels I draw the spline e.g. for the hood in the top view, then go into side and front view to get the splineS bent exactly how it should be in all three dimensions. But take great care at this step as it is NOT a no-brainer to change splinecage once you start building the mesh on top of it.

Second step is not always that straight forward. I now have a spline cage in place which I can use for points snapping when creating plygons. Sometimes to understand the mesh flow better, I do some wireframe paintovers on some reference photos in photoshop with my wacom. But do remember that this step cannot be taught in my opinion, this can only be learned through practice. Then I create a single polygon which basically covers the particular area in the most simplistic fashion. e.g. for the door panel I just create a simple quad which stretches out into all the corners of the door panel. Then comes the cutting and finetuning. I then do the cuts in the polygon where they're necessary e.g. the crease in the door, more edges to achieve the curvature etc. Never manually place the points on the edges of panels, only use snapping to the splinecage!!!

At this point you should have the main body panels created, but without the bevel on the edges, which gives a nice thick feel to the body panels. This totally boils down to the tools that your particular applican offers. The end result for the panel edges and corners should look something like this:

There's one row of polygons going inwards and there are two rows of polygons on the surface edge of the body plate. The two polygon rows have a total width of about 2,5-3,5 mm. To produce the edge bevels in Cinema 4D I use the following steps:

• select all polygons
• clone
• extrude inward or do a negative smooth shift of about 1,5mm
• delete the cloned polygons
• optimize to weld overlaping points at the newly created crease
• the outer facing polygons I extrude inner for two steps, 1-1,5mm each
• add the necessary cuts at the corners to crea a sharp corner

As for all the rest of the points on the bodyplate that aren't exactly on the splinecage, there I use the brush tool in smear mode with very low strength to give minute adjustments where necessary. This is the most time consuming part of the whole process as one change needs to be view at and adjusted from all the angles. It's also possible to use the iron tool or the brush tool in the smooth mode to achieve some inital smoothing from which to work onwards.

I hope this gives a little more insight into the way I model. Look forward for more modeling tutorials covering some very specific subjects like proper edge beveling, sharp corner modeling etc. And don't think this tutorial applies to only cars - the described process can be used to produce almost any hard surface(non-organic) object.

kthnxbai,
Mihkel