Last week I was working on a project involving several light boxes. The lightbox design was rather simple; a cube with cutout shapes which would act both as a decorative object and provide some degree of illumination for the event. I wanted to do a 3D lighting rendering in order to both wrap my head around these things as well as have something to show to collaborators. The solution was not as simple as I had hoped.
My first attempt was to construct the 3D versions just like I would construct the actual lightbox. As such I made a 3D black box with the design on the facing cut out. I then added a thin rectangle on each side that I was intending would be the translucent material on the lightbox through which light would shine. Sadly, I discovered that for all of its wonderful work rendering accurate shadows, solid textures, and correct placement of the sun, one thing Renderworks does not do well is translucent materials. This seems like a big gap in an otherwise fantastic program.
Not one to be deterred by technological limitations, I began to explore alternate options for creating the effect that I wanted. While a bit convoluted, I did end up with a reasonable result.
The first potential solution was presented by Kevin Lee Allen. His suggestion was to make the part that in reality would be translucent as a texture with constant reflectivity. Thus, when rendered, the lightbox would have the appearance of a thing that is glowing. While this is a very good solution, and one that would work in most instances, especially for scenic renderings, it did not solve one of my design requirements. I wanted to know both what the boxes would look like as well as what effect their glow would have on the scene. So my search continued.
I started scrolling through all the drop down menus in hopes of something providing me with a clue. Finally something did. A convert option that is new to me, although I admittedly jumped from VW10.5 to VW2010 and this feature may have been in place for years, Area Lights.
Line Lights and Area Lights are intended to provide a look akin to neon or other non-point source lights. They give a somewhat even glow and are fully customizable as per any other light object in Vectorworks. One thing to be aware of with these is they add considerably to rendering time. Even my very simple sketches took noticeably longer to render once I had added an area light. That said, they are a fantastic tool.
Convert to Area Light and its similar option, convert to Line Light, solved my need precisely. Instead of a translucent object that light would shine though, I placed an area light the same shape as the bounce directly in front of the bounce object. I then gave the bounce object an opaque texture. The Area Light then hits the opaque object and bounces off, thus lighting the scene from the lightbox.
While the solution is not technically identical to the real life solution, it does solve the two parallel issues of rendering the lightbox to look as it would and provides illumination from the lightbox onto the scene. From a few additional experiments it appears as though this solution could work for lighting cycs as well.
The whole world of 3D rendering is fairly new to me. It is exciting to discover these limitations of the software and then find more or less elegant solutions within the possibilities of what the software can do. But I am sure there are other solutions to this same problem. Have you discovered them? Please share.
One thing I would love to see in future releases of Renderworks is more accurate translucent texturing. I imagine architects and scenic designers both would love to have translucent curtains that render properly.
Tags: design, lighting, rendering, vectorworks, vectorworks 2010
