Back in may 09 Mr. Sameer Sahasrabudhe (Project Manager at IITB*, Center of Excellence) contacted me for his work that requires help with Blender. I landed at Mumbai on 5th July. Upon arrival, I got his call, he asked me to come over to his house to discuss few things with his students Chirag and Nitin.Continue reading “IIT Bombay – blender walkthrough”
Unlike my previous tutorial on modeling the Toyota Celica car this article is not a step by step modeling tutorial for a beginner. What I have tried to tackle in this article is some useful approaches towards modeling the car body in blender. Although it looks and feel like a walk though I have tried to tackle some common problems while modeling a car in Blender which I hope will be useful to another car modeler in blenderverse.
While it has been emphasized often in many car modeling tutorials, the need to gather or ‘research’ various data including photographs of cars and its various parts to help get the modeler and ready reference during modeling.
Much before I start modeling I try to remember the shape and unique features of the car body while going through the references and if possible the actual car, this helps me to consciously identify the possible problems in the mesh while I model, of course having the reference images ready helps to solve any doubts that I may have during modeling also.
Needless to say, they are the very basis of accuracy that you want from your model. more accurate they are the more possibility of you being able to making near to the accurate model. I said near to accurate, because Blender does no offers measurement in real life units, even if you convert them to Blender units somehow there will always be a possibility of ambiguities in calculations. However if you are close they will be hardly noticeable.
While many users prefer to have the blueprints setup in a typical box-like fashion. I find them blocking my way while I model. So it’s mostly a personal preference. Choose whatever you feel comfortable with. We have carried setting up blueprints in a box style in one of our earlier issues, you can consult it if you like to use blueprints that way. I feel comfortable with using Blenders ability to show images in the viewports. For the viable scope of this article, I am assuming you know how to do that already.
There are various shape and sizes of blueprints available on web so first step is to edit them in an image editor like GIMP or your preferred application. We are using the blueprints of Nissan350z that can be found on the site http://www.the-blueprints.com.
There is often a problem that most blenderheads have to deal often and those are
- Different proportions in different views and
- Nonalignment of blueprints in different views.
Proportion problem occurs as most users just cut the blueprints without taking in consideration that Blender view-port somehow distorts (long back Pafuriaz had written an explanation for it) the proportions depending upon the resolution.
Step 1 Fixing the blueprint proportions problem
Make a single square document in your image editor with the maximum width being that of the blueprint. We choose square as we are giving Blender all images(views) of same size thus making sure that all are displayed in the viewport in the same proportion.
First copy all top, side and another view in separate layers in the image editor. While we are in the image editor we can do the required transformations of different parts of the blueprint so that they can be represented incorrect view ports in Blender.
I always choose to have the top view of blueprint in the vertical position as it compliments both front and back view nicely in the viewports. So if your top view is horizontal you might want to make it vertical by rotating it.
Now create a new layer on top and draw a line of single pixel in the middle of the document. Taking this as reference you can move the top, front, and the back view shots in the vertical middle. Now again draw two reference lines one above the car and the other at the bottom of tires. This will give you the reference for fixing the position of a side, front and back. If you did this step nicely you can have the four different reference setup like in the images below.
|Illustration 1: Back view with guides.|
|Illustration 2: Top view with guides.|
Step 2 Alignment problem in view-ports.
If you have followed the last part properly you will have a good chance to put this up correctly. Now all you have to do is split Blender’s windows into four sections and include the respective image(views) in the viewport like the Fig 1. (The screen shot has been taken in Blender2.4 RC1).
You can enable the viewport name from the preferences menu int the ‘View & Controls’ tab (View Name). So you can see in which view projection you are in. Notice the Offset numerical buttons, these are the keys for you to align your image, here the reference lines we placed on the blueprint image in last step help you to get a good alignment.
Now just to make sure your alignment is working all you have to do is insert an cube primitive and start extruding it in top view if the extrusion is outwards then it should b outward in front as well as back view and towards the user or the side view. See Fig4 for example.
Modeling Car Body
There are two approaches towards polygon modeling a car in Blender one is ‘Box modeling’ and another is ‘Plane modeling’. They are completely opposite in nature, one attempts to create shape in blocks and then approach towards detailing while the later attempts to do it directly but in parts.
Step 1 Plane modeling: I have no experience with box modeling so I will go about explaining few approaches which could save you time and effort while modeling a car body using ‘Plane modeling’. The best way to work is usually to work with parts like the front fender or the bonnet, see illustration 3 for more.
We can start immediately by adding a plane in the side view. Before doing that position the cursor as seen in the Fig 2.
Position it over the front fender and reduce its size so that it can cover the contours of the fender just above the tire as in Fig 4.
Step 2 Constructing geometry: You should enable Subsurf of the value 2 for view-port if your graphics card can handle it. One thing you need to keep in mind while you are modeling with blueprints is that you will have to model and recheck the mesh in three views. Three because once you are modeling for example the front part, the back view will not be useful for any references. If you are not doing it often enough you will be ruining the geometry of the mesh. So immediately checking and modifying in other views as soon as you make some major changes in the mesh in one view will allow you to keep your mesh in clean state.
Following this now get into top view and move the top vertices a little back and extrude a set of another vertices towards the bonnet of the car to cover the mesh fas seen in the Fig 5a. Now move the vertices as seen in Fig 5b following the contours of the front fender.
TIP: While modeling a car body in SubSurf it is advisable to initially use only very few extrusion to chalk out the basic outline of the shape or contour of the part. For example in Fig 5a we have use only three extrusions to make the side of the fender mesh. While we will need more cuts in it to create more detail but that can come later. This method will allow you to have a great control over the mesh complexity.
Following the method we will now immediately switch to side view again and adjust the contour or shape there as can be seen in Fig 6 the result of which can be seen in Fig 7 and Fig 8.
Step 3 Detailing: Always add more vertices or extrusions in which you can see the major portion of the part for example we can sideview shows major portion of the fender. Switch to it and add more extrusions to cover other portions in this view. And following the step 2 correct the geometry in top and front views. An initial and corrected version can be seen in Fig 9 and 10 respectively.
a) Bends or contour lines: The shapes of car have often pointed surface guides or bends like near the fender rim and a slight elevation near to the bonnet in this car(Nissan350z). These unique bends can be seen in the Fig 10 as highlighted orange edge lines.
In Subsurface you will need approximately three edge liken nearby to bring out sharp bends. In Fig 10 you can see that the fender rim looks pretty sharp as in the real life images of the car. TO achieve the sharp blending it will help if you keep your mesh in clean state by only allowing to have quad faces near the place where the bend or sharp contour will be placed.
Placing an bend is as easy as using the loop cut tool at the required part. Check Fig 11 for the results.
Fig 10: Emphasizing contours.
b) Clean edges. All the body parts of the car are bent inside to created a clean edge look. we have to replicate it in our mesh too to get quality models. Here all of the outermost edges are selected and extruded once. Now the movement of the extrusion should be downwards for the part that are at top and it should be inwards for the part that are at side and again inwards for the parts that are at front or back.
To understand watch the Fig 13 carefully. You will need to select and move the extruded parts separately.
Fig 13: The edge details after extrusions.
TIP: Snapping. It is a good idea to enable snapping from the preferences menu, as the car modeling is all about detailing and when you move vertices of edges in perspective view the snapping could help you a lot, like while extruding to create and bend it will give you nice known results.