When you first take up 3D, there is so much to it that it can overwhelm a new user. There is a lot to learn about making game or film assets besides the basic sculpting or molding of mesh. Things like clean topology, triple AAA texturing, and low poly count. Best practices and industry standards follow hand in hand.
An area vastly underrated and misunderstood by new 3D artists is the low poly process. In particular, the high poly to low poly baking process takes details from a high poly sculpt and projects them via certain map channels like bump, normal or height, to a low poly version of the same model.
Years ago, low poly modeling was mainly a mindset that started with a lot of pre-planning for the result. You started in low poly, stayed in low poly, and let the textures do the work. Today things are a bit different. The results in many cases are achieved by modeling the original in high poly then using a baking process to transfer those high poly details to a low poly sculpt without increasing mesh count.
This method requires a bit of preplanning since you need to have a low poly and high poly version of your model at the end of the modeling period to use in the baking process. If all of this is clear as mud to you at this point, then don’t worry as you are not alone. Many of us have walked this path.
While it helps to understand why and how certain things work, that knowledge can be confusing and overwhelming to new users. So just follow along and you’ll see what we are doing, the result will shed light on the process for many.
In its most simplified form, baking transfers mesh-based information to map-based information. Map-based is much lighter on a 3D engine and therefore nimbler in terms of the effect on gameplay or cinematic replay.
In this case, I transferred the default female mesh from Character Creator 3 into ZBrush via GoZ as the base mesh. Using the Mesh Project tool, I drew out the helmet in segments then made Boolean cuts with alpha brushes for the detail. The high poly model is north of 2 million. The low poly is less than 10 percent of that and could be reduced further if necessary.
The low poly model was the original model. The first one I made. In ZBrush, I duplicated it as another tool before starting to subdivide and Boolean cut the details in with the alpha brushes. Think of the details as being “stamped” on the model. Usually, a single click or drag out with the mouse. Nothing fancy that requires advanced skills.
At this point, we have the low and high poly models we need for the baking process. It is important to note that you load the LOW POLY mesh into the “New” popup dialog when starting the project in Substance Painter.
This next step is critical as it is where you reference the high poly model needed to bake the maps out necessary for the details to transfer. These maps will contain the detail that was formerly found in the mesh. To the computer, in simplified terms, it’s all code that achieves the same results with fewer resources.
Baking the maps is one of the first steps in Substance Painter even without a high poly model. The Baking dialog has an option to use the low poly mesh for baking which you do want to do when not using a high poly model for detail.
The Baking Dialog from Substance Painter. Area highlighted is where you load the high poly version of the model or check the box to use the low poly version.
From here it’s all Substance Painter and you get to watch the magic happen as it transfers the high poly map channel information to the low poly mesh. Now you can paint, drag and drop textures, add masks and generators, and generally do your own magic.
The Baking Process From High Poly to Low Poly in Substance Painter.
Remember... always make a copy of the low poly mesh or tool before you start subdividing and adding detail for the high poly version in whatever 3D modeling application you use. Some apps call this projection, some call it baking and it is very effective in lowering polycount while maintaining visual quality.
M.D. McCallum, aka WarLord, is an international award-winning commercial graphics artist, 3D animator, published author, project director, and webmaster with a freelance career that spans over 20 years. Now retired, M.D. is currently working part-time on writing and select character development projects. You can learn more about MD on his website.