Marcelo Eder shows his process for creating the cover image of Ballistic Publishing's newly released ELEMENTAL 3.
CGSociety :: Tutorial, 15 July 2008
Marcelo Eder tells us the story behind his image, ‘Homage to Sidonio Porto’, selected for the cover of ELEMENTAL 3, Ballistic Publishing’s latest offering to the 3D community.
The idea behind the realization of this image has followed me since my college days, when I saw for the first time the work of the amazing Sidonio Porto, a renowned Brazilian architect. Unfortunately, it remained a mere dream for a long time, since I was always very busy with freelance work after my ‘normal’ day jobs. “Homage to Sidonio Porto” was made in 3ds Max, AutoCAD and Photoshop, and rendered with mental ray. The whole scene took eleven days to be finished, working a few hours a day; some days just a few minutes. Unfortunately the time was short, but I wish to be able to work longer on this image in the near future for a short animation.
This part was a nightmare, I must admit. I live far away from the building itself, so it was impossible to take any photos of the actual place, and the references found in the Internet were very small indeed. That can be a big problem when doing something with so many details and with such a complex structure. Fortunately, after searching high and low, I found an old magazine with a big photo of the building that showed the whole model. That was a relief.
This is a very important part of the job. I made a lot of hand drawings to generate the feel of the project, the angles and proportions and so on. Making a drawing is never a waste of time though, it helps to avoid lots of mistakes that occur when modeling something based on photos and, maybe because of my architectural education, I just can’t start something without thousands of preliminary sketches. The next step was the sketch in AutoCAD; it helped me to keep everything under control, with precise angles, sizes etc. I also used this sketch to place the whole structure in the right place with great precision. Mind you, I don't have many of them anymore, I made them when I was living in another city and lost them while moving.
This part was quite simple to do since it didn’t have any organic modeling. Everything was done with modified primitives using box modeling and a lot of spline modeling, extruding splines along a path. Most of this process was done in AutoCAD. It may sounds weird, but I was searching for precision, and AutoCAD had some amazing tools to place, measure, and extrude things. The grass was done using particle flow, using a modified plane in the Shape Instance slot.
I used common UV mappings to do almost everything in this scene, since I didn’t have the time to unwrap everything. I left the unwrapping for only the really necessary parts. For the aged metal I used some Mix materials, with a rust map on the mask slot. Mix materials can save a lot of time when you’re planning to do this kind of material.
The initial idea was to recreate the building like it is, with a shiny, clean white metal, but that would make the scene looks so “computer generated” that it would spoil all the illusion and mood I was looking for. So I decided to add all the scratches, dirt and rust we see in the final image, making the render much more interesting in my opinion, and removing the so common “too perfect” look we see in some architectural visualization jobs. To paint the rust masks, I used a tablet and lots of photos of real aged metal in Photoshop. To put the scratches in the right positions, I used the images took from Texporter as a base.
For lighting, I used only a simple daylight system, with a mental ray sun and a mental ray sky. I adjusted the sun position, looking for a late afternoon lighting.
The brightness and contrast were controlled via Exposure Control, in the Environment and Effects tab.
The rendering was quite simple, using only final gathering with 500 rays per FG point. As you can see, the secret here is a well-positioned camera and the materials, since the render settings are quite basic.
Here I created the exact mood I was looking for, starting with a violet photo filter over the whole scene to prepare the image for the following corrections, like a shadow/highlight modifier to reveal the dark areas. Some exposure changes and color balance adjustments were made to reach the violet lighting as well.
I duplicated this layer and set the new one as an overlay copy with 40% opacity to get a vivid and better contrast. An occlusion pass was added as well, revealing all the little details in the structure. The final step was the sky, and I used a photo above a gradient ramp from violet to soft yellow.
I was very pleased with the final image. Of course with the time passing by, we start to see things we could have done better, or easier, but it’s part of the whole process of eternal learning we’re in.
My name is Marcelo Eder Cunha, I am 28 years old, an architect, born and raised in Sao Paulo, Brazil. I’ve been working with 3D for four years, from architectural visualization to character animation and visual effects for television and commercials. Right now I’m working as a freelancer, doing some jobs for the Brazilian aircraft manufacturer Embraer.
The industry segment I enjoy the most is environment creation and character modeling, but everything related to CG pleases me a lot. My goal is to improve my skills to work on the game or movie industry as an environment or character artist, my two passions"
