Inventor Studio
Published Tue 20 May 2008
Research we’ve conducted into the use of Rendering and Visualisation indicates that most users get stuck with light, scene and material set-up. So, here’s our guide to getting a good basic rendering without spending too much time on set-up. And as Inventor 2009 now includes the ability to import and export materials, lighting set-ups and scenes, we’ve done exactly that and the scene and lighting conditions have been exported and made available to download.
1 Scene set-up
The scene you place your model in is just as important as the model itself. All too often a nicely rendered product model is ruined because someone thought it was a good idea to put their product on an entirely incongruous slab of marble. Remember: Rule Number one in the Rendering Handbook is “No Marble (unless it’s a sink).” It’s better to have a plain background which matches the intended purpose (Word, PowerPoint, printed material, posters etc) so it can be better included in the design–and it doesn’t get much more neutral than black or white. And just in case you were wondering, Rule Number two is “Always use Perspective.”
Tip: Inventor allows you to create a gradated background, with separate colours for the top and bottom. To achieve the same results, you can’t set both top and bottom to pure white as the reflections won’t show up in the ground plane. It’s best to set the bottom colour slightly off white and then they will.
2 Bump maps
Bump Maps allow you to represent surface textures without having to model them directly. By using an alpha mask (a black and white image) to control the height of the ‘bump’ (whiter means higher), Inventor allows you to add greater detail to a component such as these rubber tyres and the plastic components.
Tip: When first getting into rendering, many users are tempted to whack up the bump map values, but the reality is to achieve a subtle image you need to wind those values down. Also, ensure that you match the scale of the bump map to the actual material.
3 Integrated textures
Inventor has a fully integrated materials library, so when you assign a material you are not only defining its mechanical properties (such as strength, density etc), but also its aesthetic properties. To edit a material it’s best to do it from within the Styles dialog, so the changes and additions are shared between all your data. There’s some good solid information in the Inventor help system to guide you through the various options.
Tip: When you define textures or materials it’s best to get the colour right first and then add in the details afterwards (such as bump mapping, reflections, etc.). A handy device is the ColourCue from Pantone (www.pantone.com) which is primarily designed for checking print colour, but can also be used to collect cool colours. RGB values are added into the Inventor material dialog.
4 Global Illumination
Inventor Studio comes with a range of lighting conditions, but in all honestly these are a bit limiting. The use of the Global Illumination is the only way to go to make your renders look really realistic. Global Illumination takes into account how light disperses within a scene, with reflection from other surfaces, all having an effect on the quality of light which makes it much more realistic.
Tip: Inventor 2009 sees the introduction of Soft Shadows. These are used to match the softness of the lighting conditions, adding up to a pretty slick image.
5 Depth of Field
One of the problems with renders is that they can look too clean if every detail is perfectly represented. One of the ways of reducing this ‘perfection index’ and improving the photorealism is to switch on Depth of Field. New to Inventor 2009, Depth of Field is a standard photography term meaning the area around a focal plane in which objects appear in focus or, looking at it from another perspective, those outside of that area that appear blurred. Within an Inventor Camera you can switch on Depth of Field and adjust the focal planes (both near and far) to control exactly what is in perfect focus in your scene. This option is fantastic for those looking to add realism and for focussing on a specific area of a rendering without having to Photoshop the image afterwards.
Tip: You can adjust Depth of Field by either using measurements, f-stops (a standard photography term), or you can adjust the near and far focal planes (shown blue and green respectively) using the triad that pops up when you select them.
