Car Tutorial Part 17 - Body Seams

Ed Ferguson, CascadiaDesignStudio.com


Mannequin by Chipp Walters http://moi3d.com/forum/index.php?webtag=MOI&msg=7351.1

Door Seams:
Draw a curve in side view to represent the door seam. A typical door for a car like this is 44” to 45” wide. Be sure your curve has a radius at the bottom corners. Sharp corners won’t look natural in the render, and will probably cause issues with the operations we’ll perform two steps down.



Next we’ll project this 2D curve onto the car body so it generates a 3D curve setting on the body surface. In top view, Perform Curve > Project and select the door curve. Select the car body as the Projection Target. Pick your Direction start and end points as a straight line perpendicular to the 2D door curve you are projecting.

The projected curve looks like this:





Just a note here about drawing the body curve seam: Keep the ends of the curve slightly away from adjoining geometry that make up the widow openings. This way the sweep (purple) we’ll perform next won’t try to cross over into other complex areas which will likely make the following steps fail. You can Show Points on the projected curve and pull the ends back slightly as needed.

In top view draw a 0.12” radius circle and move it near (but not touching or intersecting) the body seam curve. This will be the profile for sweeping the door seam.

By keeping the circle (profile) slightly away and off of the curve (rail), we are telling the Sweep function to use Auto-place mode. Auto-place mode keeps the profile (circle) perpendicular to the rail as it sweeps, which is very important for this step.

Select the circle (profile) and perform Sweep (Freeform, Regular, Auto) with capped ends, using the projected 3D door seam curve as the rail.

Boolean > Difference the car body with the purple tube created by the sweep. The result is a half-round channel representing the door seam.



Repeat these steps for the opposite door, re-using your 2D door curve.
Verify the body has remained a solid after this operation.



In your render program you can darken/lighten the paint color of the seams slightly to make them more or less pronounced according to your taste.

Use the same technique for other body seams such as the hood. In this case your 2D curve, drawn in top view, will be a closed curve.