Ptex is one of the more amazing technologies, allowing you to paint extremely high resolution textures on a per polygon basis, as well as completely bypassing all UV work - as it does not require any manual input for the creation of the UV maps. Ptex, in it’s current implementation, only supports quad polygons, no triangles or N-gons.

It’s important to note that when using Ptex in 3DCoat, you can increase the resolution of individual polygons if you require more texture details in the local area of that polygon. By increasing the resolution of a polygon, or group of polygons, it is effectively increasing the size of that polygon on the auto generated Ptex UV map.

For example, you could paint very small details inside of areas on a mesh which calls for an extreme close up shot or just requires more detail in one particular area - yet, you don’t want to create a lot of very high resolution texture maps. Ptex works quite well for this purpose.

What is even more remarkable is that the .ptex format can store hundreds of thousands of textures directly with in one .ptex file. At this time, only external application that supports the .ptex format will be able to import/export the .ptex file for use. To fill in this gap in .ptex support, we have provided for the export of an ordinary texture map, based on Ptex technology, in the .TGA, .BMP, and .PNG formats.

Upon importing a mesh for Ptex painting, you will be prompted to select a number of options:

Millions of polygons: This is the mesh resolution as subdivided after the “Smooth object” operation is performed.
This should be higher than the number of pixels of your texture map.
Carcass resolution: This is the mid-poly resolution, it only effects the viewport performance and display of the mesh in the viewport.

Ptex Texture Size for Export

You can select a texture resolution between 512×512 and 8192×8192. You can also change this at any time you need to scale up or down your texture resolution.

Weld vertices: This will weld any vertices which share the same position.
Swap Y and Z: This will swap the Y and Z axes. This allows for an easier time when bring meshes from applications such as Rhino or 3DSMax.
Ignore smoothing groups: Ticking this will ignore any smoothing groups which you have on your mesh.
Invert normals: This will flip the normals of each polygon. Auto smoothing groups: Will automatically scan the mesh for sharp angles between polygons, and apply smoothing groups to them automatically, maintaining any sharp edges that are present.
Each of the following Ptex functions requires a selection. To make a selection, simply activate the Ptex Local resolution tool and “paint over” the polygons in the viewport.

Local Resolution parameters

Clear: Clear any selection.
Invert selection: Inverts your selection.
Expand: Expands your selection by one contiguous polygon.
Contract: Contracts your selection by one contiguous polygon.
Select level: Manually key a local polygonal subdivision level.
Increase resolution: Increases the local resolution of the currently selected polygons. This effectively increases the polygon size on the auto generated Ptex UV maps.
Decrease resolution: Decrease the local resolution of the currently selected polygons. This effectively decreases the polygon size of the auto generated Ptex UV maps.
To max level: Sets your current selection to the maximum level allowed for Ptex. Effectively increasing selected polygons nearly taking up their own UV map.
To min level: Sets your current selection to the minimum level allowed for Ptex. Effectively shrinking selected polygons, allowing more polygons per UV map.
Ptex Texture Size: You can pick the texture resolution for each ptex generated texture. Selectable resolutions range from as low as 512×512 to as high as 8192×8192. You can change this at any time to suit your needs, as well as upon importing the mesh for ptex painting.
Optimize: Organizes polygons on every auto generated Ptex UV map to fit more polygons, based on local resolution (poly size per UV space).
NOTE: When using this, do keep in mind that if you have been using a mesh with specific auto generated Ptex UV maps, it will completely reorganize the polys on all UV maps, rendering your previous auto generated UV maps useless.
However, you can always bake the details from one mesh to another. Just be sure to save two meshes:
Your original and the baking target mesh. For more information on Ptex, please visit the official Ptex website at

  • general/paint_workspace/ptex_painting.txt
  • Last modified: 2019/10/08 12:01
  • by carlosan