In the example above, a procedural noise texture was created with a Texture Project and used as a mask to blend between two material layers. Each layer has a different Bevel Width, resulting in a dented edge effect.

Map Types

Bevels create normal map detail and affect the Ambient Occlusion and Curvature maps, so you don’t need to use another application to generate this data. This feature is exclusive to Toolbag’s baker and makes it easy to jump straight to the texturing process.

Mesh Considerations

Toolbag does not currently support baking texture maps directly from the low poly model, so you will need a high and low polygon pair. You may be able to use a copy of your low poly mesh, with a bevel material applied, as the high poly. For simple assets, this can work well.

While using the same mesh for both the high and low slots can be an easy way to speed up the modeling process, there are situations where the meshes should be different. Let’s dive into the details.

Varying Levels of Detail

As with traditional baking workflows, there’s often a need for different levels of detail in the high and low. This could be fine surface details like screws, panels, seams, or other types of greebling that only exist in the high.

With this example, the high poly mesh is very different from the low, as it often is with traditional baking workflows. Rather than being a replacement for needing to create a high poly mesh, the bevel shader workflow provides an alternative to creating a detailed subdivision surface mesh. We can work with a lighter, easier-to-edit mesh and worry less about quad-based topology, edge flow, control loops, etc.

There are cases where you may want details in your low that aren’t in your high as well. That may sound counterintuitive, but if we consider that the high poly is not the end goal but rather a means to generate the normal map, it makes more sense. In this case, I want to keep the high poly simple so it’s easy to edit during the initial creation process. However, this might be a part that will be seen up close, so for the final low poly mesh, I added a chamfer to the metal shell and rounded the edge for the soft plastic part to improve the silhouette and shading.

It’s worth mentioning that the wireframes are rather messy in some of these examples. While you want to make sure the final topology for the low poly mesh is clean, efficient, and shades well, this doesn’t necessarily apply to the high poly. As long as the high shades well and the bevels work as expected, there isn’t any need to clean up the mesh or follow the traditional rules that you might be familiar with for subdivision modeling. This allows us to work more freely, using techniques like booleans or CAD modeling that would otherwise be considered unsuitable for this kind of work.

However, you may need to triangulate complex n-gons before importing your mesh to Toolbag. In these examples, I have broken the n-gons up minimally for the wireframe renders to illustrate how messy the geometry is. But for the final bake, the meshes have been triangulated to ensure the shading is correct and that complex n-gons do not collapse into unexpected shapes.

Seams and Hard Edges

As with traditional baking workflows, we need to be mindful of how our UVs and hard edges are laid out for the low poly mesh. If a hard edge is used in an area where the UVs are a contiguous island, this will create a seam artifact in the normal map.

To counteract this, it’s important to make sure our UV islands are split wherever we use hard edges. With a bevel baking workflow, we will typically control the bevel placement with hard edges. This means that if our high and low poly meshes have the same geometry and mesh normals, we may need to use too many hard edges and split our UV layout into more islands than is necessary for the low.

The image below shows that the key difference between the high and low models is how the hard edges or mesh normals are set up. For the high, the hard edges define bevel placement. For the low, the normals are averaged so we can use an optimal UV layout. Face-weighted normals would be appropriate for the low as well.

Merging Meshes

While it isn’t necessary to merge the parts that make up the high poly mesh, it can be beneficial to do this for the low poly. Parts with large intersections or overlaps can create inefficient UV layouts, as you end up dedicating texture space to areas that won’t be visible. Note the black areas in the image below.

Merging is a good way to squeeze out the maximum amount of detail for your textures. Especially with complex assets, as the empty sections can be filled with smaller parts. That said, merging can increase the triangle count and add time and effort to the process. So it’s worth considering how beneficial it is on a per-asset basis.

As covered in the Varying Bevel Size section, assigning more materials can be a good way to fine-tune the bevel size on complex parts. However, this can mean using more materials than necessary to define the surface regions, resulting in too many colors in the Material ID map.

As a workaround, you can define your ID colors manually. This can be accomplished by configuring the albedo color for each material, allowing you to use the same color for different materials that share the same surface type.

For example, if you have three materials to set different sizes for bare metal parts, make sure the albedo color matches for all three. Then, in your Bake Project settings, hit the Configure button in the Maps panel, and enable the Albedo map type.

The image above uses relatively simple meshes and boolean modeling techniques with the bevel shader applied to round the edges for the majority of the parts. Sub-d is used for the pump, taking advantage of the ability to make smooth curves with ease. Mixing these techniques provides a great deal of flexibility, providing precise control over curves and edges where you need it and significantly speeding up the process when material-based bevels can be used.

Part Welding

You can create parts that appear to be welded or molded by intersecting different objects. This is a great trick that can save tons of time and make changes in design easier to manage. Since we don’t need to boolean or physically combine the meshes, the freedom to adjust the individual elements that make up a complex design is maintained.

If you don’t want nearby parts to appear welded, use separate mesh objects and enable the Bevel Same Surface Only setting in the corresponding material. This setting allows you to mix and match behaviors for complex assets. For example, it should be enabled for animated parts or separate pieces that are flush with another surface.

Traditionally, polygon modeling software was preferred for hard-surface subdivision modeling as clean poly flow was essential for adding edge loops required to maintain forms. The bevel shading workflow adapts better to the topology generated by CAD software, making these applications a much more friendly, viable choice in a modern production environment.