The file size of Zbrush models has a direct correlation with the amount of polygons the model has. The more polygons there are the larger the file. This can be reduced by using tactics like retopology and texture maps such as normal & displacement maps.
Adaptive size defines a vertex ratio based on the curvature of the mesh. To maintain the original mesh shape, ZRemesher may need to increase the topology density in certain areas or produce triangles rather than quad polygons. On the left, Adaptive Size is set to 0.
The quickest and most simple way to retopologise a model is to use ZRemesher. It is as simple as telling ZBrush how many polygons you want and clicking the button. Find it in Tool > Geometry > ZRemesher. The input number is in 1,000s, so if you put five you will get roughly 5,000 polygons.
To use the Decimate Geometry tool while editing a model in Blender:
- Select the model and switch to Edit Mode.
- Select Mesh > Clean up > Decimate Geometry from the bottom menu.
- In the Decimate Geometry options, set Ratio to the percentage by which to reduce the triangle count.
- Save the file and export as an .
To recalculate the normals:
- Hit the Tab key or click to switch over to Edit mode.
- Under the Mesh menu, click on the Normals option, then click “Recalculate Outside†(hotkey: Ctrl+N) or “Recalculate Inside†(hotkey: Shift+Ctrl+N).
Decimating 3D scan data simply means you are making your file size smaller by reducing the number of polygons in your 3D mesh. If done properly, you can maintain relatively good accuracy and resolution compared to the original file, without compromising on quality.
The Simplify Mesh command simplifies mesh objects by reducing the number of polygon faces.
To simplify one or more meshes:
- Select the mesh object to simplify.
- Select Modify > Simplify Mesh.
- Click OK to simplify the mesh object to the specified quality.
Once you have chosen which model you want to decimate, you can load it into 3D Builder. From there you will need to go to the edit tab and click simplify. Here you will see a slider that allows you to chose the percentage of triangle to reduce the model by, the higher the percentage, the more triangles will be removed.
The simplest way to add a new vertex in Blender starts in Edit mode. Simply hold Ctrl and press the right mouse button to add a vertex wherever your cursor is located. To then create a new edge between this vertex and a selected one, hold down Ctrl and press the right mouse button again.
ZBrush
| Fullscreen screenshot of ZBrush 4.0 |
|---|
| Developer(s) | Pixologic |
| Initial release | 1999 |
| Stable release | ZBrush 2021.7.1 / September 14, 2021 |
| Operating system | Windows 10 version 1709 and later macOS 10.13 and later |
Dynamesh creates topology that essentially only cares about maintaining the surface volume while providing a consistent density of polygons (in order to create a model that is ideal for sculpting on). You can see that zremesher has a nicer flow to it, but doesn't always use consistently sized polygons.
DynaMesh has been designed to create low and middle resolution sculpting stages, making it a perfect way to create your base mesh before diving deeper into all the powerful traditional ZBrush sculpting and editing tools. DynaMesh is a mode which can be used with the primitives in ZBrush.
To activate Dynamesh, open the Geometry tool palette and click on the Dynamesh option. Simply click the large Dynamesh button to create your new topology, then continue sculpting. Over time your polys might distort again, so simply Ctrl + Drag Click the background to reproject a dynamesh over the model.
The Dynamic Subdivision system contains alternative functions to ZBrush's Classic Subdivision Surface mode, allowing you to apply dynamic smoothing to your models without actually dividing the polygons. This feature is mainly designed to work in association with the ZModeler brush and low polygonal models.
Sculptris Pro is a global editing mode for ZBrush that provides unique behavior for multiple sculpting and painting brushes. As you sculpt, ZBrush will add or remove polygons as necessary based on your brush size.
Go to the Preferences menu and then scroll down to Geometry. Open up the Geometry section and you will see there is a “Dynamesh Close Holes†slider. By default it's set to 4. Set it to 0 and you will be able to Dynamesh without closing holes.
