GroBoto Coordinate Systems:
GroBoto's SeamNet Mesh engine is designed to handle just about anything you throw at it. However, there are a few things you can do to improve mesh quality, and avoid straining that engine.Mesh Density -
Density needs to be reasonable...too low
and you'll get a chaotic, awkward mesh — too high
can lead to performance and/or RAM trouble. Either much too high
or much too low
can cause mesh generation to fail.
See the Mesh Density
item on this page for Guidelines & Tips.GroBoto's built-in bots, (with default v2 settings), are Not the place to start.
See the Bots & SeamNet Meshes
section of this page for more info.Bugs Welcome -
Please let us know if you encounter any GroBoto Model that fails to mesh
. Of course, we ask that you check density settings, but if they are reasonable, we expect the mesh to succeed, and definitely want to fix anything that does not. GroBoto saves a temporary file
every time you preview a mesh, so even if there is a freeze or crash, you should be able to send us the .gbr file.
|Bots & SeamNet Meshes
Extraordinary models are produced by combining GroBot's Bot Generated forms with SeamNet Mesh exports — especially when those meshes are sculpted in apps like ZBrush or MudBox (as seen in some of the images here). However, a bit of common sense is required...GroBoto's built-in bots, (with default settings), are Not the place to start.
They were not configured with meshing in mind (they predate SeamNet Meshes). While GroBoto can mesh nearly all of them (given enough RAM and the right mesh settings), they are very demanding models requiring some SeamNet knowledge and experience.
It's best to work your way up
to complex Bots. GroBoto's Mesh engine handles Bot complexity remarkably well, but every system has limits. Simply running out of RAM can prevent a mesh from completing. Bots easily create many thousands of objects — potentially more than 100 million polygons if density is too high.Try a single AutoBot with about 100 to 500 objects
first to get the feel of things. Set Reasonable Mesh Densities -
With Bots, the best bet is the ‘Variable’ option with a Density around 32 and a Minimum of 8. Key size should be based on a primitive in the middle of the Bots range of object sizes.
GroBoto's SeamNet Meshes have two elements:Seam NetworksPatch Grids
The Seam Network
tracks the model's edges with multi-row edge loops. These special rows of Quads lie on the perfectly smooth intersections & edges of your model. You control their width and distribution of quads.
Quad Patch Grids
are ideally oriented to the curvature of surfaces. You control grid density (both absolute and relative sizes between objects).
These meshes are very workable ('tho not perfect). They will become more fluid & continuous as we move forward.
Understanding the interaction of Seams & Patches — and roles they play in subsequent modeling & sculpting — is key to getting the most out of your SeamNet Exports. The Tips & Techniques
sections on this page will help you achieve optimal resultsDevelopment Note:
We will provide options for smoothing, rounding and other edge/seam interpretations within GroBoto very soon.
|Modeling for Meshes
Other Tips & Techniques
sections on this page cover practical considerations, but first a few thoughts about the fundamental, qualitative difference GroBoto's mesh capabilities bring to your work. The power & freedom comes from Automation
and the Mesh Structure
. Automated Mesh Generation -
frees you to focus on form & design... refine, reshape, rethink, as much as you like during the concept & design stages. No need to preconceive everything before 'committing' to mesh creation— regenerating a mesh only takes a moment.
GroBoto resolves complex topologies automatically — no need to restrict your design ideas to those that fit limited topological configurations.
The power of GroBoto Modeling flows from these dynamic and interactive aspects — take advantage of them
. As usual, your best bet is to explore. Create some simple meshes with various densities, seam settings and export options — see how they fit into your specific workflow and toolset.SeamNet Structure -
combined with GroBoto's grouping and UV masking Export Options
are essential aids to further modeling outside of GroBoto. Their potential uses in other apps is too varied to cover here. We have provided some examples in the 'Quadric College' forum, and will be adding more tutorials and videos.
|Setting Mesh Density
Interface pages describe destiny settings in detail. Here are some general tips:
Use enough density -
That is, densities that let the Patch Grid mesh to flow into your models corners and narrow channels..Control Relative Mesh Density & Set Key Density -
When radically different quads sizes meet, GroBoto must stitch very few big-quad points to a lot of small ones — resulting in an irregular mesh. GroBoto has options for automatically adjusting densities based on primitive sizes and a 'Key' object. These options keep quad sizes closer while efficiently handling large and small features in your model.See #2, 3, 4 - Mesh Export page.Control Density Locally -
using the per-object density overrides in the Selections & Groups Panel
. See #11 - Mesh Export page
.Use Don't Unify Groups
option to separate components of your model. This option places GroBoto Groups in separate (un-unified) meshes. See #8 - Mesh Export page
SeamNet Meshes are great for sculpting and subdivision modeling. GroBoto’s Seams act as Edge Loops. The distribution of seam quads rows effect how the mesh reacts to subdivision, editing, and sculpting.Keep Seam Width reasonable.
Wide seams are good for rounding or smoothing your mesh in another app. However, the wider the seam, the more likely you'll see odd polys in your mesh (seams themselves are always very orderly, but the rest of the mesh must adjust to accommodate them). Simpler models — with lots of room between seams — handle wide seams more easily.
Seam widths greater than 100% (% is relative neighboring ‘body quads), should be used with caution. The combination of wide seams and ‘crowded’ seam networks, can cause mesh generation to fail.
It’s fine to broaden seams so they collide with one another (happens in most models -- even when seams are narrow). It’s more of a relative thing... when seams become so wide that they crowd out most of the body mesh, more irregular/elongated polys occur.The Seam Crease
Note how changes in Seam Crease settings move the innermost row of quads nearer or farther from the center of the seam. When the crease is narrow, a sharp edge will tend to persist when subdividing or sculpting... when broad, it becomes easier to round and smooth.
GroBoto's Mesh Smoothing tools do more than simply smooth edges and valleys. They produce Seam Styles
— variations in the seam width and profile. Several settings effect the Seam Style, including Seam Width, Seam Rows, and — of particular interest — Seam Crease.
When the Round
option is selected in the Popup menu next to the Border Slider, the Seam Crease Slider directly controls the profile of rounded seams.
Those Profiles range from:
• Flat Bevel (-95%)
• Fully rounded (0%)
• Sharply Creased (100% +)
The effect will vary depending on the angle of the original seam. Caution:
High Crease (values > 100%) may lead to self-intersecting meshes. Nothing bad will happen, except odd rendering. It's a good idea to zoom in and examine any sharp edges if to set this value high.
The ‘High Cap’ slider Determines where the transition occurs between the Cylindrical Grid and the Square Cap Grid.
Higher settings create the largest Cap Grids with quad sizes similar to those on the cylindrical part of the mesh.
Lower settings make the cap grid smaller. This gives a better radial structure (ex. around the seam where the side wall meets the top and bottom of a cylinder).
NOTE: A second ‘Lo Cap’ Slider is available in Selections & Groups Panel. Lo Cap allows for separate settings at either end of all primitives (except spheres, hyperrods and ellipsoids).
There are a few things to avoid when exporting SeamNet Meshes.
Typical SeamNet Mesh Uses:
Use 'High-Enough' Density -
Scene Elements - Final Meshes for rendering another app.
Traditional Mesh Modeling - Set-up for further modification in Modo, Maya, 3DS Max, Silo, etc.
Sculpting - Base Meshes for high-poly sculpting in ZBrush, Mudbox, etc.
Appropriate density depends on what you plan to do with the exported mesh. Two examples:Render Only
- Lower density meshes look more chaotic, but are fine for any standard smooth shaded rendering. Vertices are precisely placed on the surface, & shading normals are ideal. The only remaining consideration is how polygonated your curved surfaces will be.Modeling/Sculpting
better to increase density in GroBoto, than subdivide in another app. One or two post-export subdivisions are ok, but the notion of the lowest possible poly-count 'base mesh' is not appropriate with GroBoto models & meshes.