Create photorealistic cars in Maya - Chapter 1
Create photorealistic cars in Maya with the help of Alexandr Novitsky's eBook, available in the shop now! Chapter 1 preview...
In this tutorial, you will discover how to begin to visualize and create a photorealistic 3D classic car. Over the next few issues, we will follow the process of modeling a car from its first blocking stages, to the final render.
During these tutorials we will use Maya for the modeling of the car, V-Ray for its visualization and Photoshop to edit the image. Despite this, it actually doesn't matter what software you use, as the emphasis will be on the principles behind the creation of a model.
We will create the 1939 Delage D8 120 Cabriolet Chapron – but using this tutorial as a base, you will be able to create any vehicle. We will also work with polygons. We will create geometry from a simple box, and will smooth it repeatedly until we obtain the desired level of detail, ultimately ending up with a highly detailed model.
First, we need a photo of the car. Shots on all sides of the vehicle are obligatory, so first let's examine the proper selection of references:
1. It is preferable that you have a photo of the car on all sides. We need to see the car's shape with all the details. If you don't have enough photos or you don't have a large shot with particular details, you need to take a pencil and draw these details in to understand the shapes.
2. It is good to know the car's sizes too: its length, width, height and wheelbase. We need it to better observe and recreate the proportions.
3. A blueprint is not all that necessary for the creation of the car. Very often they are incorrect, though they can help during those first stages in the creation of the model, when we need to build the main shape quickly and correctly. If you don't have a blueprint, it's not a problem, as photos and the car's sizes will be enough.
Problems with references
There can be many problems with reference images. The most common mistakes during the work with references are as follows:
If you have a photo with the side view of the car, you may wish to load it into the side projection and start to create a chassis with this photo. This will ultimately end up being incorrect as it will lead to distortion of the overall shape of the model. The point is that the photo has a perspective which will cause a strong distortion. If you don't have a blueprint with a side view, it is better to simply trust your eyes.
Another problem can be caused by using photos without taking the camera's characteristics into account. Usually we use up to five photos to create the accurate shape and there is potential for mistakes when setting the scene's camera differently to the settings of the camera that was used for taking the photo. If you made the references yourself, you can see the settings of your camera by just right-clicking on the filename and choosing Properties > Details. If you don't know the settings of your photo, you need to set the camera manually. It takes time, but it helps a lot in comparing your photo and model.
Regardless of our approach in the creation of conditions for modeling, the chief thing is not to make the mistakes described above. Of course, it is possible to create a car without any photos or blueprints, but the outcome will depend on how well your eye is developed. If you don't trust your sense of proportions or you want to be absolutely sure, you need to use some auxiliary pictures. The chief thing is not to confuse photos with blueprints and not to use them as replacements for one-another.
If you load a blueprint, do it through the Image Plane and don't forget to choose Looking Through Camera in the Image Plane Attributes.
As for the present model, we have only one photo which makes our task much more interesting. The car is exclusive, so there aren't as many photos as we'd like. But we have all that is necessary.
When working with similar cars, the chief thing is to take the uniqueness of these cars into consideration. Multiple car models are frequently made on the same basis, so you can find photos or blueprints of a very similar car to work on (remember to recognize and apply the differences in detail though).
So, beginning the process of creation of the model, we create a simple box.
It is important to place this box in the center of the interface co-ordinates. Also, this box must have the overall dimensions of the car. For example, if you know the car's length, width, and height, you should set them as the dimensions of that box.
The next step is to divide the box exactly in half. We need to cut exactly in the center of the co-ordinates. If the box is displaced, you need to align it along the grid by using the snapkey X. Next, delete one half and copy the existing object with the Instance Value, reflecting the geometry. Set a value of -1 in the corresponding cell of the Duplicate Special Options, to reflect the block.
We have two halves and each is part of our future car. To complicate the shape, we need to add polygons. We can do this now, remembering that the chief thing is to divide each edge exactly in half.
We could also have initially created a box with the required number of edges (the number of edges may have been different though).
Bending the geometry
Next, we begin to work with the shape. First, we will bend the geometry a little.
It is very important to understand that in this case, the shape of the chassis will consist of three parts; a basis and two front fenders. So initially, we will leave a straight line on the sides and will bend the geometry only at the center. After a simple manipulation, we can create the shape seen here.
Refining the shape
Now we can safely leave the pentagons and triangles behind. At this stage, our goal is to give our geometry a better car shape. We delineate the chassis and fenders. To make our work easier later, we need a more precise shape. At this moment, the topology does not matter so we can leave the unmarked areas, but the edges must be aligned. At this stage, we show the chassis' main elements. Also, we can delete the bottom completely to make our work easier.
When we make an object that looks like a car's chassis, we need to regulate the many angles according to the details shown in the original photo. We can always use primitives for this task.
Now we have the basic shapes down for the creation of the car, we can begin to bevel the edges. Don't be in a hurry with the detail.
Despite the fact that we just outlined the car's chassis, now it is very important to feel the shape of the car and make corrections to the model according to the shapes in the photo. The chief thing is to see our halved sections completed. Imagine that you have a finished car and then complete any absent parts mentally.
When we correct the shape, it's important to remove the triangles and pentagons to make the shape smoother. We just need to choose any of the halves and set the Exponential Smooth Type value to 1.
You should obtain something similar to this.
Trim the mesh
Now we have many more polygons than we began with. We need to trim the mesh and set the Harden Edge value to Normal. Now you should be left with a simple exterior.
In this step, we need to make many corrections at once:
1. Make a cylinder and place it where there should be a wheel arch. Cut through the mesh and align all the tops of the cylinders.
2. Simplify the bonnet and make it narrower towards the grill.
3. Set the edge at the place where the center of the wheel should be and watch out for the neighboring edges – they do not need to be joined together.
4. Clear the mesh from the side – this is not obligatory, but simple geometry is always better. Also remove any unnecessary polygons, leaving only the most necessary ones. We can always add new polygons later if we need to.
5. Remove some polygons from the interior. Also work over the trunk, lowering the rear fender according to the photo.
At this point, it is important to form a precise mesh. We don't need an ideal mesh; we need a basis for further work, so try to make your mesh smoother and more logical. Also it is important to mark all principal places on the chassis by one or two edges.
It is no problem if you accidentally remove any extra edges. The chief thing is not to break the formed structure and to observe order in the mesh. If the edges are placed chaotically and without observance of distance, you will likely have a problem with the shape. You should focus on having a well arranged mesh, even if you remove several sections later on.
Next, we add some Bevels and complicate the geometry a bit where it's needed. We need to emphasize the chassis' principal lines. For now, you will need to make a single edge, so we can form a specific mesh around that edge later.
Check the mesh
Remember we will smooth the mesh later on to obtain the required accuracy. At this point, that mesh should contain as few triangles and polygons as possible.
The base model
Now we have a basic model for future work. At this stage, we have full freedom to edit any dubious areas and correct the proportions. Don't forget to check with reference photos and look at the model from different sides.
Make sure you rotate your model often; look at the model from different sides and try to imagine the finished car. Also, try not to get lost in contemplation of your reference photos. Switch between photos faster and try to catch the whole shape: it can make further work easier. Finally, don't be in a hurry with details. First, you need to create a basic shape and then move from the general to the particular.