Rendering effects you can add to 3-D scenes include fog, lens flares and shadows.
Rendering in digital 3-D modeling refers to the process your PC uses to produce a simulated 3-D image of a model or a whole scene of models. You initiate this process after creating a model with a computer-aided design (CAD) program. The CAD program gathers all factors impacting the appearance of the model–the lighting, viewpoint, focal length of the camera lens, atmospheric, and other effects–then computes each visible pixel (picture element) of the model based on those factors. Rendering 3-D models allows you to create photo-realistic images not easily produced with other kinds of graphic software.
1. Open your CAD program, then click the “Draw” menu’s “Box” function. (Search your program’s help file for “Creating objects” for your program’s name for the “Draw” menu if you don’t see this menu.) This action initiates a mode for drawing 3-D boxes. You’ll produce a variety of effects that impact the box’s rendered image.
2. Click and drag in the drawing window to define the box’s base, then release the mouse and drag upward to grow its height. Release the mouse to end the box creation mode.
3. Click your “View” menu’s “Render” function to produce an initial rendered view of the box.
4. Create another box, then click the toolbar’s “Move” tool. Drag the new box under the first box, then click the “Scale” tool.
5. Drag the new box’s height-sizing handle until the box’s height is as shallow as possible. Drag the width and height sizing handles until the box’s surface is much larger than that of the first box. This second box will simulate the ground under the first box.
6. Press “F9” to perform another render. Note that no shadow appears on the ground, as it would in the physical world. You’ll create a renderable shadow in the next few steps.
7. Click the “Light” item under the “Draw” menu, then drag upward to position the light anywhere above the two boxes.
8. Check the “Shadows” checkbox in the light’s parameter pane. This action turns on shadows for the light you just added.
9. Press “F9” to re-render the scene with the boxes. The “ground” box will now display a shadow thrown by the first box.
10. Click the “Draw” menu’s “Camera” item, then click and drag near the scene’s boxes to add a camera to the scene.
11. Right-click the camera and select the “Set viewport to camera” item to display the camera’s viewpoint.
12. Press “F9” to render the scene as the camera sees it, then check the “Orthographic projection” checkbox in the camera’s parameter pane. This action will replace the realistic perspective view (i.e. converging lines) of the scene with an orthographic (i.e. straight lines) view. (Orthographic views make hand-drawn additions to rendered views easier because all parallel lines in a scene appear as parallel.)
13. Press “F9” to render the orthographic view of the scene. The rendered image will appear (correctly) distorted, due to its parallel lines no longer converging from perspective.