Making of "Croatian Dream" by Matej Hosak
This image was part of a project we have been commissioned at Vyonyx studio. It was a large scale urban-planning project, encompassing several images and an animation. Our client wanted to achieve the authentic atmosphere of a Croatian landscape (one could even say genius loci), so for this particular shot we have used one of the aerial photos as a reference.
Everything had to be modelled to a certain level of detail. Our main focus was on the new-built city and surrounding satellites. We used mainly Lightwave and Rhino when necessary.
Since we were working on conventional single-CPU i7 machines, the big challenge was to put together the terrain which had to be split into several segments. The client provided high-res terrain data, including satellite imagery which had to be split too. Eventually, we ended up with 10 terrain segments - 1mil polys each - and textures ranging between 3k x 3k and 10k x 10k, depending on the distance to camera.
If one wants to achieve nice water effects showing different depth, it’s essential to model the seabed – this pays off especially for animations.
Once the terrain and building models were ready, the real fun of populating started! We used a couple of ways to populate the scene:
1. The most convenient is, of course, density maps, which were basically the same satellite images used for color channel but adjusted in Photoshop to B&W where black represents areas without trees and white represents trees.
2. Geometry created specially in areas where we want to populate with specific plantings – projected on the terrain so that it copies the topography and then is either hidden from render or moved couple of centimetres below the terrain. This is handy for areas like distant forest, vineries, olive groves etc.
3. Per-tree geometry – in close-ups, mainly in the city area where we needed the ability to control the position of every tree.
4. and then of course we used the standard ecosystem in areas where homogenous planting was desirable.
Once all this detailing was done and we were satisfied with the location of objects and vegetation, we were ready for the last big challenge. This challenge was to render – client required an insane resolution so that individual persons would be visible! So we proposed 12000 x 8160 pixels. The problem with resolutions like this is obviously the render time, so in order to be able to afford global radiosity, we had to precalculate the prepass on more reasonable resolution 5000 pixels, which took only a couple of hours; then the full render (unfortunately with the “ignore indirect lighting on plants” option turned ON) took about 30 hours on single CPU (i7 920) machine.
Of course we needed a lot of flexibility, so we rendered couple of channels in multi-pass, like object and material ID, indirect illumination, shadows, diffuse, reflections etc, which gave us the possibility to tweak stuff later in Photoshop. So the final 750MB tif as rendered:
And the final composite after postprocessing:
Hope some of this helps!