Tutorial on how to model a car. (Part 2)

Awp Harsh

8 Jun, 2013 10:15 AM

Since the Camaro is very popular car you have the benefit of using the manufacturer’s website. If you go to www.chevy.com you can “build your own” Camaro. Inside here you can rotate the car 360degrees. This is a valuable asset when trying to figure out body lines and I recommend you do this when possible.

1. Step 1:

   When you plan out the approach to modeling this car you need to look at the hard lines of the body and find good places to break up your surfaces. The door and front fender keep the same bodylines but the rear fender flares out. so at a first glance I want to model the door and front fender first. Sometimes
   it’s best to start with the roofline or the glass but I think the side of the body will give the most trouble so I want to tackle it first. Start a new sketch on the Right Plane and we are going to layout the top ridge of the fender/door. Start by drawing a spline from the front edge of the fender to the back edge of the
   door like below.
   

   

2. Step 2:

   Now use the spline handles to control the curve and match the shape of the body. I ended up with my handles like this.
   

   

3. Step 3:

   Keep in mind when making these splines that the body lines on other parts like the front nose cone will end up with a tangent relation. Make sure your handles are reasonable in their direction to account for this. End the sketch and start a new sketch on the Top Plane. We want to draw the same body line we just did, only from the Top View. In some cases (such as this) I like to use Convert Entities on that first sketch onto the top plane and make it a construction line. The reason I do this is so I can add a horizontal relation. It helps me early on in the model to know my blueprints are in a reasonable spot and that my project curves will hit where I want them to. Again you only want to draw the start and end of your spline. Make them horizontal from the endpoints of your converted construction line and make sure they hit the same spot on the blueprint image as our original sketch.
   

   

4. Step 4:

   More important than exactly matching the line on the blueprint is ensuring that you have a nice stable spline. The blueprint images are pixilated and not exact in most cases. Use your judgment to know when a deviation from the blueprint is warranted. So far we can hit these curves by only using the endpoint handles. You will find this to be the case for most things. If you end up with 4 or more spline points you may want to take a step back and see if there is another way to approach the model. Now with our first two sketches we can make our first projected curve. This is the procedure that we will follow for the entire model with slight variations of course. Most notably will be how and where we add relations and what type of surfaces we will be creating with these curves. I have added the Curves button to my quick menu(S key on the keyboard). I find with models like that that I use it enough to warrant putting it there. You can find it on your Features tab or Surfaces tab under Curves. It’s important to note the two differences in projection types for Projected Curves.

   Sketch on Sketch will allow you to take two 2d sketches and create a 3d curve where they meet. Sketch on face will be used later possibly for things like sweep paths for window seals. This allows you to take a single 2d sketch and project it onto a 3d surface. Make sure you use Sketch on Sketch for now until otherwise noted.

   Select both sketches and create your first bodyline. Now for some reason these projected curves often aren’t visible when a sketch blueprint is there so you may need to rotate the model or hide some of the blueprint sketches to see this curve. If you select the curve in the window or in the feature tree it should be easier to see. Also take this opportunity to rename Curve1 to something meaningful and notice that both 2d sketches are consumed by the Curve1 feature because they are children to it. Once we use this curve along with others to create a surface this will happen again. I named mine Fender Door Ridge.
   

   

5. Step 5:

   From here on out I will give you very general guidelines to help, but the point is to learn and not regurgitate. I won’t be telling you to OK the sketch, it’s just implied. If I use something new I will point it out but the procedure is the same from here on out for the majority of the body. The next curve will be the front edge of the fender. In a new sketch on the Right Plane I draw a vertical line. I select the end point of the line and the 3d curve from the previous step and add a coincident constraint. Here it’s important to note the pierce constraint. An example of the pierce constraint would be drawing a 2d sketch where a 3d curve will intersect this sketch at some point. Pierce will make your sketch intersect this 3d curve. In this case our 2d sketch is on the Right plane while our curve never intersects this plane, so coincident must be used. Also you may notice if you select the endpoint of your 3d curve that you have no relation options. This is because the endpoint doesn’t lie on the plane. However if you select the entire curve it will be “projected” but not actually drawn in your sketch. Make sure after you apply the coincident relation that you try to move your line all the way to the end of your curve. If you are not at the endpoint it will cause issues with your surfaces so this is important. Another thing you could do is use Convert Entities on your 3d curve or you can go back to the 2d curve on the right plane. This is possibly a more stable method because it allows you to pick an end point. This way if you go back and edit curves they will more than likely update better. I will let you make the call on how you do this because part of learning is finding out what works and what doesn’t. It’s a good idea to create a new part and play around with these projected curves and watch what happens when you make changes.