Introducing Solid Edge Rendering31 Jan, 2003 By: J. Fred White
In an environment where manufacturers face tremendous pressures to get products to market quickly, engineering changes can impact delivery and costs. The ability to render realistic product views greatly reduces miscommunication between customer and designer long before the design reaches manufacturing. Renderings also provide increased understanding and confidence on the shop floor and open up a more timely use of product data by other departments, such as sales, marketing, service, and technical publications--without the need for expensive prototypes.
The view and faces styles available in Solid Edge allow you to apply photorealistic rendering effects. View styles affect the entire view; faces styles affect individual parts. With these tools, you can add new effects such as anti-aliasing, textures, bump maps, background images, reflections, shadows, light color, and light angle.
Figure 1. You can apply texture images that represent material types such as wood, brushed aluminum, or marble.
Anti-aliasing. Applying anti-aliasing to a part or assembly window reduces or removes the jagged display of angular edges. The more anti-aliasing you apply, the smoother the display will be, but it will also take longer to process.
Textures. You can use an image to apply a texture to a part in an assembly, as shown in Figure 1. For example, you can apply texture images that represent material types such as wood, brushed aluminum, or marble.
Bump Maps. You can also use an image to define a bump map on a part in an assembly. Bump maps add realism by creating the appearance of surface-relief shading on a part, as shown in Figure 2.
Figure 2. Applying bump maps on a model creates the appearance of surface-relief shading.
Background Images and Reflections. Background images can make parts and assemblies look more realistic. For example, you can apply a background image of a road scene or construction site behind a backhoe assembly. You can also define an image that is reflected off surfaces. That image can be used for background and reflection, or separate images can be used.
Shadows. In assemblies, you can specify face styles that define whether a part will cast a shadow onto another part and whether a part will accept shadows from adjacent parts.
Light Color and Angle. Light-source properties allow you to assign color and angle properties to each of the eight individual light sources.
The more rendering options you apply, the greater the impact on display speed. Using the Format View dialog box, you can toggle these effects off and on. Toggling off the rendering effects makes parts display faster. So, while you are designing parts, you may want to temporarily disable some of these rendering options. Then you could switch back to the enhanced view at any time to admire your work.
Ray-traced images take more time to generate, but their quality is much higher. The main difference between normal and ray-traced shading is that the latter gives part-to-part reflections. That's why ray-traced images take much longer to process; the amount of computation required to generate these reflections is tremendous.
Check to make sure all attributes and styles for individual parts are properly set before you ray trace an assembly. Test the view orientation, reflection boxes, and shadow settings in a simple view style to make sure the shadows and background display properly. You can then create a ray-traced image of the file. If you are unsure about the results, run a small test area in ray-trace mode to optimize hardware time.
You can only ray-trace an image in the Virtual Studio environment, which is accessible from the Environment menu. Virtual Studio also has tools for creating animations.
Rendering is a broad and extensive process, so there is no established rules. There are, however, several general techniques that you can apply to most rendering jobs. There will be exceptions, especially for highly reflective or highly transparent renderings. Once you finish an assembly, you are ready to render an image using the following steps (they aren't linear and you may have to revisit a step during the process):
- Orient the assembly to the desired view.
- Test the lighting of the assembly. Three seems to be enough lights for most rendering projects. Turning on more lights doesn't necessarily guarantee anything other than a longer processing time.
- Test the "fall" of the shadows and adjust the lights accordingly.
- Select and apply unique part colors if desired, and set the attributes of part colors for transparency, reflectivity, and shininess.
- If desired, select and apply textures and bump patterns. You may need to adjust lights to avoid washing out colors or textures.
You should also run a couple of sample areas to test lighting, shadows, bump maps, and textures.
Once you have the desired attributes set, turn on anti-aliasing and render the complete view.
Figure 3. While rendering a complex object with all of its details and nuances requires significant system resources, the results are well worth it.
Rendering something complex, such as the model in Figure 3, takes time and patience. Small adjustments can make a huge impact on image quality, so I've compiled some tips that can help improve image quality:
- Leave textures, shadows, depth fading, and reflectance off until all parts have color and textures assigned.
- Keep anti-aliasing turned off until ready to generate the final image.
- Test attributes of the colors and textures with lighting, shadows, depth-fading textures, and reflectance off.
- Test the lights and shadows together. Textures and reflectance should be off.
- Test the highlight and reflectance areas of the image with Render Area before rendering the complete view. Adjust the attributes accordingly.
- If a part has some level of reflectivity, there must be something to reflect onto the part for the reflectivity to be seen. Use the environment box or change the angle of the view so adjacent parts get reflected on these types of parts.
- Using "Chrome" for the Reflection Box value works for most reflection needs.
- Turn off shadows for transparent parts. The missing shadow won't be noticed in most cases and the image will be easier to understand.
- The Surface textures function places one texture per surface. World textures compute a consistent scale between the texture image and each individual surface based on the model's scale.
Every project is different, so one tip may work for one project but not another. After you have created several images with the Solid Edge Rendering tools, you can start to adapt your own tips and processes to making product renderings. Have fun!
About the Author: J. Fred White
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