Car Body - Adding Detail

Panel Separation


Up until now, we've treated this car body as a single surface object, with only the hood and trunk being separated from the whole. We all know that this isn't the case in reality, that there are in fact several panels that make up the surface of a car. It adds a little bit of flare to the model to include these panel separations in some regard. I have heard some suggest the best way to do this is with bump maps, but I don't think that is necessarily true. In the case of HyperNURBS, I think it would be just as much work or more to use bump maps to achieve this effect, with no real benefit. That being said, let's model them...





We will remove the door from the car body first and create a separate door object. But first, we have to make an adjustment to the definition of the door bottom.

When the knife cuts were made in the planning stage, a double cut for the bottom of the door was omitted in favor of a single cut to make the side of the car easier to shape smoothly.


A double cut is actually preferable to make the edge of the door, and since the side of the car is already shaped adequately, we can simply select all polygons and run a horizontal knife cut right above the bottom door edge.

This will keep the curvature of all the elements along this area consistent.



Now we can go about the business of selecting all the polygons of the body object that will be separated to form the door object.


Make sure that when selecting these polygons, you get all of one row of the narrow polygons that surround the larger obvious ones.




Again the reason these narrow ones are there at all is to keep very strict control over where all our edges remain when the split is made.


The strip along the bottom of the car is actually part of the rear panel, to be separated along with the rest of the back end further down on this page.



With these polygons selected, run the Split command in the Structure menu, under the Edit Surface sub menu.

Just as with the trunk and hood objects we performed this on earlier, a separate object is made.

Place this object under a Symmetry object parent, and then place the Symmetry object group under a HyperNURBS parent.



Switching back to the original car body object, you can still see the original selection of polygons highlighted. Using the structure manager in polygon mode, delete these polygons.

You should now have a car body object with door cutouts, and separate doors that fit exactly within these cutouts.

After the deletion of the polygons, remember to switch to point mode and optimize to get rid of unused points.



Moving on to the separation of the back surface from the front surface, we'll follow the technique identically.

Select all polygons in the back end of the car, including the strip that runs underneath the door object.


Make sure to select polygons very thoroughly. When we performed some of the detail enhancing steps, we created a LOT of very narrow polygons in our HyperNURBS cage, and these may be easily missed, especially in the tail fin area. (In case you are wondering, I say this because YES I missed some polygons on several attempts before getting it correct!!!) :-)


Split these polygons and group them under the appropriate Symmetry and HyperNURBS objects.



Return back to the car body object and delete the original polygon selection. (Once again, optimize unused points to keep things clean!)



At the end of this, if you check the edge of the panel underneath the front of the door, you may find a little bit of a looseness in the way that the edge of bottom strip meets the remaining front panel.


This is mainly because such a long, narrow, sparsely-polygoned area is then pinned with only a single knife cut on the very end. The solution I used was a single knife cut dividing the end polygon in half, thus dramatically increasing the influence of the narrow edge polygons and forcing the interpolated HyperNURBS surface into the correct shape.


So now that the panels are separated, they are that much closer to looking great in a render. Except for the fact that they are paper thin and that just LOOKS wrong. We'll fix that soon by adding some thickness to the panels in areas where this thickness should be visible in an upcoming step, but first, we'll take care of the wheel well shaping...

On to the next step.