This was a quick piece for
fun. I was inspired by all of the heavily destroyed cement cover in
Gears of War. After posting, information on how it was created was
request, so I documented the process. This could all be optimized
further, but again, it was a quick fun piece not originally intended
for any use or tutorial creation.
Base Mesh
Block out a simple shape. It's important to keep it all quads of equal
size before sculpting to get the best results out of Zbrush or Mudbox.
Sculpt
With simple sculpting, it's easy to get a rocky organic shape. Start
with the largest shapes and slowly reduce your brush shape (note: if it
doesn't look right with the large scale details, adding smaller details
probably won't help). Finalize with a stencil/stamp detail for the
smallest details.
Close-Up The high detail mesh is
just under 400,000 triangles. Working with a mesh this detailed can be
a headache, so it's good to get used to it now. Up close, the mesh is
incredibly detailed.
Low Poly Build a low poly mesh
based closely on the high detail. It may help to copy the high and
optimize it. Not for the final low, but to use as a base that isn't
such a system hog. A low poly mesh with normal maps needs to be rounder
than a regular low poly mesh, and a single smoothing group. This is so
that lighting can hit the normal from as many rounded angle as
possible. Any hard edges should be on the normal map itself. UV's need
to be as seamless as possible with minimal stretching.
Diffuse
I created a destroyed cement texture in Photoshop by touching up
several cement photos. Heal brush the edges where the seams are with
the same sections of the overlay to reduce seams.
Specular map created by taking the diffuse > contrast +50 > hue +180
Normal map For information on how to generate a normal map in max from a high detail mesh, read this spotlight article http://www.game-artist.net/forums/showthread.php?t=43
I generated a normal map for this using CrazyBump beta. The main site
allows you to sign up for the beta, but more info and a download can be
found in this thread http://boards.polycount.net/showflat...&Number=148897 Always render out a Height Map. While not used in this example, it can always come in handy.
Ambient Occlusion Be sure to: Create > Lights > Skylight In Max, same as rendering a Normal Map but when you get to the Add > NormalsMap step, also Add > LightingMap and finally, render as you would the normal map This process can be done at the same time as normal map rendering also, and this is usually when I do it. This will create a white material with depth and shadows based on the high detail mesh.
Multiply this over your diffuse in photoshop (or vise versa), adding an
incredible amount of depth and quality to your material.
Final Materials As always, with these materials, it's all about testing and looking it over from all angles
About Author
Full Article
