Sculpting a Modular Stone Staircase in Autodesk Mudbox
In this tutorial you will learn the fundamentals of sculpting hi-poly environment art. We will cover the process of creating an optimized base mesh in 3ds Max, and then export it into Autodesk Mudbox to sculpt in the details, starting with the larger forms, eventually working our way down to the smaller details, and finally using alphas to add surface detail.
Every few weeks, we revisit some of our reader's favorite posts from throughout the history of the site. This tutorial was first published in January of 2010.
Final Effect Preview
Select the box tool from the sidebar.
Click and drag on the grid, then enter the dimensions. You may choose different dimensions of your own design if you like.
Select the hierarchy tab, and click 'Affect Pivot Only'. In the Top viewport, move the pivot to the corner of the box.
Access your array menu by going to "Tools >Array".
Click the preview button, and alter the settings as shown below. Depending on the dimensions of your box you may have to change these to suit your setup.
You should now have something similar to below.
Convert one of the boxes to an editable poly by right clicking and going to "Convert > Convert to Editable Poly".
Select the "Attach" tool from the sidebar, attach all of your boxes into the same object.
Select a ring of edges around one of your boxes. Select the connect tool from the sidebar, and use 2 segments to break up the steps into smaller construction blocks.
Connect rings around your object to match the following image, and alternating between 2 and 3 segments. It will help to have hotkeys for popular functions such as connect and extrude.
Select all the edges that you just created and click the "Chamfer" button. Enter '1' in the 'Chamfer Amount' option. This value may vary depending on the box dimensions.
Enter into polygon mode by pressing 4, select the polygons in between the chamfer you just created, and delete them.
Your mesh should now look like this.
Zoom in between the blocks, select the opposing edges, and use the "Bridge" function from the sidebar.
Your mesh should now look similar to this.
Select horizontal rings and use the "Connect" tool from the sidebar. Enter around -70 in the 'Slide' option.
Your tpology should now look like this.
Select the polygons within the sections you have just created, and hit "Extrude". Change the type to 'Local Normal', and enter a value of 3.0.
Select the edges that you won't be needing, and delete them using Ctrl+Backspace. This will delete edges and verts together.
Your mesh should now look like this.
Select the backfacing polygons that won't be needed, and delete them using the delete key. We do this because they aren't needed, and it is pointless to waste precious Mudbox resolution on something that won't even get sculpted.
The faces that aren't needed are now deleted.
Your mesh still looks the same from the front.
It's time to export your base mesh from 3ds Max and get it into Mudbox. After selecting your object, go to "File > Export Selected".
Name your file according to your personal choice. It is good practice to keep naming conventions, for example I called this 'Environ_Stair_Basemesh'.
Import your object using "File > Import". As this is an environment object, and not an organic character, you don't want the first few sub-division levels to smooth out your hard-surface definition. Now go to "Mesh > Add New Subdivion Level" and click the box next to it.
Make sure "Smooth Positions" is un-ticked. This means you can sub-divide without loosing your lovely hard edges.
You may find it helpful to enable Full Screen mode when sculpting, this will give a larger view of your object.
It's useful to have some ambient occlusion to help show different height levels within your object, anything such as cracks, bullet holes, and gaps will have ambient shadows when this option is turned on.
The first thing to do is sub-divide by pressing Ctrl+D. Your mesh from 3ds Max is currently extremely uniform. This isn't the case in real life and especially not the case in games. Since this environment piece is inspired by the GOW universe we'll have to anticipate battles raging around it, decades of use without being cleaned, hundreds of soldiers using the stairs every day and therefore loads of 'wear and tear'....you get the idea. Select the "Grab" tool from the main toolbar and begin to make some of those sides uneven. Don't go overboard, we're looking for subtle changes here. It helps to visualize the prop being used, and visualize how it gets damaged.
Sub-divide again, and using the scrape tool sculpt over the very sharp edges of your stairs. This will give it a chipped and worn feel. Once again, don't go overboard...less is sometimes more. You may also want to start working in larger bullet holes, or chipping off corners of the stairs. The overhang is the thinnest, and therefore the most fragile piece of stone, so it will be damaged the most.
Continue to add larger types of damage. Don't go near the alphas yet though, just work in the larger forms before getting into the nitpicky stuff. Using the sculpt brush, take off the corners of the stairs, especially where they could be kicked and used the most.
Now that you have your basic damage down, you can work in a simple alpha image to get some form of what kind of material it is. In this instance the bottom of the stairs are brick, while the top slabs are granite. Select the brick stencil that comes default with mudbox, and an image will appear on your screen.
Select your sculpt brush, and sculpt onto the front and side faces where the brick would appear. Scaling is extremely important at this point, because you don't want tiny or mis-aligned bricks. Think about how large the asset is in comparison to the world, things tend to get built accurately and therefore will be aligned correctly. Don't worry we can damage it later.
When working with hard-surface environments in sculpting software, you may find it easier to use a solid falloff, this will avoid any ice-cream like patches that will make your concrete look and feel like a marshmellow.
Continue to use the brick alpha while adding some basic detail. The way the brick was laid at the side of the stairs will match the front, so you don't want four bricks vertically on one side and then only two on the front....make sure they match up.
Cover all of the surface that is suppose to be brick. Your mesh should now look like this, although it may feel a little soft. We'll solve that next.
Select the "Contrast" brush from the tool panel. This will sharpen your height values, and make your bricks look a whole lot better.
Use the "Contrast" brush along the gaps between the bricks. This will bring them out a lot more and give you an effect that doesn't just look like alphas slapped on.
Your mesh should now look like this. The brick is far more professional now that it has enhanced contrast. It may help to add deeper cracks along the brick lines in some places. This will give it a more dynamic and life-like feel.
Select the alpha underneath the off button. This is an interesting stone texture that will benefit you with some minor surface detail. You may choose to select another alpha depending on your preference.
Using the "Sculpt" brush, sculpt interesting sections of the alpha onto the model. Try to keep all of your surface detail similar in size.
Use the alpha on the top of all the slabs, remembering not to go over the top with the depth or detail. A low-poly version may only have 512 or 1024 textures so things such as minor surface detail is just wasting time.
Use the default "Sculpt" tool and increase the depth of the cracks between the brick. You don't want it to look like an alpha has just been applied and left as that, or that would just look amateur. Depending on how defined you would like it to be, you may also choose to use the contrast tool to really bring out the gaps.
To avoid a spongy feel, you want to make the edges of your bricks hard. To do this, use the "Scrape" tool, and remove the sharper edges from your brick. This is the limit of how small you should want your details to go. Smaller details won't show up on the normal maps when baked out.
Depending on how damaged you want your staircase, use the "Scrape" brush further, and scratch off the side of your brick. The edge of the brick would have been one of the first things to crumble and fall off with prolonged use.
Here is the finished sculpted environment asset. I chose not to take off the edges of the brick excessively, though you may choose to decide otherwise. As previously mentioned, less can sometimes be more when applying damage to game assets. Subtle changes that catch the eye and make you think are better then just slapping on loads of destruction, dirt, and damage.