New Article: Rendering Intent: To Illustrate or to Sell

Colin Finkle, our CAD/industrial designer blogger, has written a new article for the site on the differences in types of rendering for MCAD and industrial design.  Not every rendering is created equal. Some renderings have different purposes than others, and to take a broad brush, one size fits all approach to renderings is doing a disservice to your designs. You need to decide whether your intent for this rendering is to sell or illustrate the design before you start. A rendering to sell is meant to convince someone that a design is the right way to move forward. On the other hand, a rendering intended to illustrate a design shows off design features, construction and added value. Read article →

Comparing rendering engines is a lot like comparing paintbrushes

Comparing rendering engines is much like comparing paintbrushes; some may allow you to do different things, but what makes them great is the artist behind them.Thankfully rendering engines are more alike than they are different. Most rendering packages that come out-of-the-box with the CAD packages industrial designers use, include features like ray-tracing, material libraries, drag and drop materials, video rendering, and wrap around textures and decals.  Some new features are upping the ante in terms of render realism. Both Photoworks for Solidworks, Autodesk ImageStudio and Pro/ENGINEER Advanced Rendering Extension have HDRI scenes. This means that High Dynamic Range (HDR) images of common places (outdoors, kitchen, photo studio) are mapped on invisible spherical environments to create great reflections and specular highlights, with matching lighting. Just a few years ago I had to work very hard to fake this capability in Photoworks.

The two main out of the box rendering packages are the afore mentioned Photoworks and Autodesk ImageStudio. I only have direct experience with Photoworks. They both have the features I mentioned before, interactive renderings, indirect illumination, and global illumination. They are both easy to use. The two are more similar than different.

But they are different. Photoworks is based on the Lightworks engine, while ImageStudio is based on the Mental Ray engine. Photoworks is used to render Solidworks models, but ImageStudio can accept Solidworks, PRO-Engineer or CATIA models using STEP or IGES standard file formats. ImageStudio has the capability to schedule renderings. ImageStudio is also optimized to be able to handle large assemblies, something with which Photoworks has a hard time.

Other out of the box rendering engines are Pro/ENGINEER Advanced Rendering Extensions and AutoCAD rendering. These have most of the standard features you would expect, and are made to meet the needs of the industries their parent programs are targeted at. They do not go above and beyond, but work as you would want them too.

Rhino has taken the different approach of having a decent out of the box rendering engine, but opening it up for and encouraging users to user 3rd party programs. Rhino interfaces with rendering engines such as V Ray, Maxwell, Bryce, Flamingo and Penguin. All of these have their own strengths and weaknesses, and will be reviewed in a future column.

To really go above and beyond with renderings, you can always use Digital Content Creation (DCC) software like 3D Studio Max. These programs have a long learning curve, but their potential is endless. I see a fair bit of designers knowing 3DS Max out of college or university. As crude as the out of the box rendering engines seem by comparison, they are easy to use. This is important because you want to spend more time designing and less time rendering - the same reason you have a workstation graphics accelerator!

Addendum: If you are interested in learning more about PhotoWorks, check out Rob Rodriguez’s blog and in particular, his PhotoWorks Rendering Contest.

Update Oct 8, 2008  A reader comment informed me that while PhotoWorks 1 was based on Lightworks, PhotoWorks 2 is based on MentalRay.  And of course, the new PhotoView 360 as an option for SolidWorks 2009, uses technology from Luxology.

Autodesk is taking a lead in GPU-enabled FX and 3D Stereo

As reported in the Siggraph 2008 blog by Pat Howk, Autodesk is making a big push to take a market lead in stereoscopic 3D for media & enertainment.

Their latest announcements at IBC further support this.  Lustre 2009 is their digital color grading system (color grading is a process for altering or enhancing the color of movie or TV images). Lustre’s two big updates:

1. The entire array of grading, previewing and rendering tools can be used for Stereoscopic 3D material
2. Real-time playback of primary and secondary color grading capabilities for multiple secondary layers are GPU-accelerated.  FX plug-ins (blur, noise, etc) are also GPU-accelerated

The Autodesk support for stereo 3D in their film and game development software moves them to the forefront of the market. Stereo 3D as part of the mainstream for CAD and visualization will most likely be next as display vendors begin to release their auto-stereoscopic displays. I am also guessing that there will be a lot more work on 3D stereo drivers from AMD and Nvidia as this market moves from infancy to adolescence.

Ambient Occlusion in Rendering for Design

While this may be old news for the digital content creators, I see a lot of industrial designers and engineers neglect ambient occlusion in their renderings. This is unfortunate, because studies have shown that this property of light allows us to perceive geometry better than direct lighting (Depth discrimination from shading under diffuse lighting, by M.S. Langer and H. H. Buelthoff). Communicating geometry is the intent of rendering for design ultimately.

Ambient occlusion is a decrease in light due to occlusion. It is the shading if the object was lit evenly from every direction, similar to an overcast day. Soft shadows form in cracks, crevices and corners because the surrounding geometries don’t let as much light in at those points. If you look at the room you are in right now, you can notice that area of the wall closer to the corner of the ceiling is slightly darker than the rest of the wall with the same light. This is because the wall blocks, or occludes, light from more and more directions as it moves closer to the corner.

While this is a subtle effect, it is one of the primary visual cues our minds look for to discern if something is real. It also shows off geometry very well. Thinking about it in your sketches or hand rendering can make your art much more realistic. As for 3D, your rendering program probably can do it, but it may require turning on Indirect Illumination, Global Illumination, or Ray Tracing. (For example, see Ambient Occlusion In Any Scene for how to enable the effect in SolidWorks). It will increase your render times, but you’ve got the horsepower so might as well use it!

New Article: Solids vs. Surface Modeling: What and why you need to know

Colin Finkle, our industrial designer blogger, has written a new article for the site on the differences between surface vs. solids modeling.  Surfaces and solids are the underlying math that defines the geometry of the forms you create. There are three ways to define 3D geometry: solids, surfaces and wireframes. Wireframes don’t play much of a role in CAD, but primarily in digital content creation (DCC) and gaming. The easiest way to understand the difference between surface and solids modeling is to think of a water balloon; the water in the balloon would be solids modeling, while the latex skin would be surface modeling. While you don’t necessarily have to understand surfaces vs. solids modeling to create high fidelity renderings, animations or simulations, knowing the limitations and the strengths of both can be very powerful knowledge, and pay big dividends in time and quality. Read article →

Submit a 2D illustration, 3D rendering or animation in the ‘Creativity for a Greener World’ contest

BOXX Technologies and AMD are co- sponsoring a contest called, “Creativity for a Greener World”.  The contest gives computer artists, industrial designers, CAD designers, architects, etc, the chance to submit a 2D illustration, 3D rendering, or a 20-second animation of their vision for a greener world such as a nonpolluting transportation system, a futuristic house with sustainable energy sources, or green consumer products. The grand prize winner receives a limited edition Brammo Enertia electric motorcycle.The zero-emissions bike is capable of more than 50 mph and has a range of about 40 miles.  Deadline is August 22, 2008. Submisstion details on the Web site.