Introduction
Imagine you and your family are on a summer-vacation in Italy. The weather is nice, the landscapes are wonderful, the houses are rural and more. But unfortunately you are in hurry and therefore driving from Point A to Point B as straight as possible. The result is obvious: although you are in some beautiful landscapes with rural houses you don’t see very much of it, the only thing you remember is the street and the area around it.
If we translate this story into the world of drawings, paintings and 3D images we can say that straight lines are necessary from time to time, but we should avoid them as much as possible in everything that is somehow something organic.
Lines vs. Curves
Instead of writing ten pages about how curves in all variations are visually more interesting it is the best to show it. Look at the following outline drawing of a part of someone’s hand:
As you can see the image could be an adequate start for a 3D image/3D model. The only problem of this image are the straight lines that form the outline of the hand. When we highlight the negative space at the top of the hand, the problem is even more visible:
As expected, the form of the negative space might be a nice start, but in the end it is visually too uninteresting and inorganic.
Now, let us take a look at a better version of this drawing:
This is quite a difference to the first version. As you can see we now don’t have a straight line broken in the middle anymore, but a myriad of curves and shapes. There are bigger as well as subtle floating curves and small ones with stronger angles and shapes.
The object we see is clearly organic and (more importantly) interesting to look at. I think one reason for this beauty of curves lies in the fact that there are many different directions (if you think in tangents) in the upper line. There are upward directions, downward directions and many more in-betweens. In the bad version, there are only two directions implied by the upper line.
By the way, here is a part of the original image I have worked with for this tutorial and which I have taken from www.vision.org:
If you look closely you can see that this image not only has the curvy lines that define the outer shape of the hand. You can also find curves on the hand itself and if you take the shape into account the number of possible curves and curvy lines seems indefinite. Each one of us can see those wonderful lines by simply taking your hand and looking at it. If you rotate your hand a little bit you immediately see completely new forms and lines.
Curves and the world of 3D
Now, perhaps one or the other may have thought “Nice, example with this dirty hand, my friend. But what has this to do with 3D images?”
Of course, it seems somehow strange to use a normal image as a n example to show the point. But on the other hand, the example is fitting quite well. Because in the end (as stated in It’s all 2D), everything we 3D artists do and create, we always end up in those two dimensions of a monitor.
So, if you are not working on an animation project, it is highly probable that you will create one image with one point of view. Hence, you can apply most 2D principles to the 3D world.
But even if you are working on something that will be really 3D in a way, an animation or a game for example, you still can apply those principles to your model.
Organic modeling? Work in curves!
Now, if we take the example of the “flat” hand image from above and translate it into the world of 3D we can say that those 2D principles still apply. Meaning, if you want to model something organic in your 3D application of choice you have to work in curves or curvy lines – and a possible indefinite number of it.
Now this might seem almost impossible as the “number” indefinite is of course quite high. But in the end this is no problem at all since any 3D image, regardless of how detailed it isand how flat it will end up, is always an abstraction of the real world. To model a sphere you don’t have to use an indefinite numbers of polygons and the same applies to any organic model.
Nevertheless the task of modeling something organic and really curvy seems hard to accomplish. How could you apply the 2D principles in an endless world with endless possibilities? Don’t worry. By using the right technique you can achieve quite goods results quite fast.
If you have an organic 3D model and you are not completely satisfied with it, take it and rotate it in any way possible (or rotate around that 3D model with the virtual camera) and check constantly its silhouette/profile. Does it contain any areas that are flat, straight or not interesting enough? If you find such areas, which are not dictated by the overall model, you can fix these areas by “adding” curves to them. This means that you could add a “valley” or a “mountain” to this area as shown by the following simple images:
As these images show, you can work on one area at a time (without losing sight of the overall model of course) and after some time you will most likely notice that your organic 3D model will look better. This applies not only to its profile but its overall appearance. As the two images show, specular highlights, shadows and shades, everything will look more interesting…
You will get the feeling that the model consists of an indefinite number of curves.
