Modeling, texturing, and lighting

Fri, 01 May 2020 13:10:00 +0000
process, modeling, texturing, lighting

The following is a generalized outline of 3D model development; there are certainly variations on the process, software, techiniques, and approach. This is just one way; but it is typically the approach we use when modeling 'from scratch'. Here's how we'll replicate this digital photo of a Gala apple.

Modeling is the first step in animation development; after all , you need something in the scene to animate. It is possible to start with a model created in other software (such as CAD/CAM: Computer Aided Design / Computer Aided Modeling). In fact, it is desireable to use such models if they exist. In this example, we will start from scratch, to illustrate the entire process. If you have done CAD/CAM or architectural work, you may find certain aspects peculiar to animation-oriented software.

We will develop a virtual model of the scene in 3 stages: modeling, texturing, and lighting. This sequence is not fixed, and is frequently iterative, that is, after some lighting work, the model and textures are adjusted, then the lighting is adjusted some more, which might point up the need for more model adjustments. Due to this flow of progressive refinement, early tests are put in front of the client to help spot any errors that would lead to wasted time in refining a model that has mistakes. These early tests may look crude in many aspects. This is even more true when animation is involved, as motion can influence where detail be omitted as superfluous, or should be increased.

Step one: the basic model.

Most animation software uses the concept of meshes to create geometry objects. A mesh can be thought of as a set of points in space (vertices) joined by lines (edges) to create solid polygons (faces).

Even if one uses smooth curves on-screen to create geometry, the curved surfaces are typically converted to meshes when the computer calculates the final rendered image. The more vertices, edges, and faces, the more potential detail in the object. But, as there is no free lunch, even in computer graphics, adding faces requires more memory, and more calculations.

Modeling frequently starts with a basic geometric shape. In this case a sphere, as that is pretty close to an apple.

Here, we’ve given the object a flat red color, and moved around some of the vertices to get closer to the shape of our real apple.

We have moved more vertices, added some detail, and smoothed the surface a bit. You can see the underlying structure, even without the edges being visible.

The next thing our apple needs is a stem. It too starts as a primitive object: a cylinder.

Some pushing, pulling, scaling and bending of the vertices gives us a more appropriate stem. We also add a curved surface underneath the apple object to simulate the laminate background used in the photo. It’s grey, so doesn’t really show up here. Now is also a good time to add a virtual camera, so we see the scene in...