ADDING MATERIALS

One of the more interesting aspects of working in 3-D is that you can visualize what your design will look like. You have so far used the hide and shade commands to give you some idea towards how the final piece will look. The next step is to learn about the RENDER command. This command is the most powerful one for viewing your objects. Using render, you are able to add realistic lighting and materials to get the most realistic view of what you're designing.

You can render objects that don't have materials applied to them, but it won't look as realistic as if you have material added.

The first two blocks shown here are examples of the usual wire-frame view before and after the HIDE command.

These two blocks show how the render command can show the object two ways. The block on the left was rendered without a material applied, while the one on the right has a white ash material applied.

Applying the materials is a relatively easy process, getting them to look exactly the way you want them to can be a skill in itself. Once the materials are added, getting the lights and shadows to look realistic is another task that most people prefer to complete in a program other than AutoCAD.

Follow these steps to get an accurate rendering:

• Draw the object using solids or surfaces

• Apply the materials

• Render the scene using the photo real or photo raytrace options.

There are a few commands that you'll need to know before working with materials and rendering. You may find that the icons are easier to use for these commands. If you need to pull up the render icon toolbar, just right click on any icon and choose render from the list in the dialog box that appears. You will see that all the commands you need are on this toolbar.

These are the major commands from the render toolbar (from left to right):

1. Hide - Removes 'hidden' lines.
2. Render - A more realistic way of viewing objects.
3. Scenes - Used to setup a particular scene with specific lights.
4. Lights - Used to add lighting to a scene.
5. Materials - Allows you to apply materials.
6. Materials Library - Allows you to choose or create materials.
7. Mapping
8. Background

Once your objects are drawn, you have to decide which materials you want to use. AutoCAD comes with a basic materials library that you can use to import materials into your drawing. To begin importing materials, you can select the material library icon, or type MATLIB at the command line. Either way will bring up this dialog box:

The materials list on the left side shows you which materials have been imported into your drawing. The Library list on the right shows you which materials you have available to you. To select a material, click on an item in the Library list then pick the preview button to see what it looks like and if you want to use that one, select the import option and it will be added to the left side. Once you have imported all of the materials you want, just select OK.

Now that the materials are in your drawing, you have to apply them to the objects. To do this either pick the materials icon or type RMAT at the command line. Doing either will bring up this dialog box:

This dialog box gives you some options. If you wanted to, you could modify the materials to customize them, but for starters, you will just apply the materials from this dialog box. First you must select the material that you want to use. Next you decide if you want to apply the material by selecting each object, or if you want to apply them by assigning a material to a particular layer. For example, you could apply a white ash material to your lamp base by (picking the Attach< option) and selecting your base, or applying the material to every object on the Base layer by choosing the By Layer… option.

Notice that you can also get to the Materials Library from this dialog box. As a rule, I just use the rmat command to access both dialogs.

Use these commands to apply materials to the lamp that you drew in Lesson 7, and other solid objects you have drawn. Materials cannot be applied to wireframe objects or those drawn with line thickness.

For even more realistic looking materials, you may have to map them as shown in Lesson 3-13.

Adding materials is a very simple process. Getting them to look exactly as you want or life-like can take some time to perfect. It is a combination of material, mapping and lighting.