Common map extraction options
Options available in the Extract Texture Maps window depend on the map types you select in the Maps to Generate list, and on the Map Type you specify in the Output options (Ptex or Texture).
This topic describes the options common to all map types. For options specific to each map, refer to the links below.
Name
Enter a name for the texture extraction settings to re-use the same operation later. The saved operation appears as an option the next time you select UVs & Maps > Extract Texture Maps.
Maps to Generate
Select the map types you want to generate. The Extract Texture Maps window displays options for each map type as you select from this list.
- Transfer Paint Layers (See Transfer paint layers and Transfer Paint Layers options.)
- Ambient Occlusion Map (See Ambient occlusion maps overview and Ambient Occlusion Map Extraction options.)
- Vector Displacement Map (See Vector displacement maps overview and Vector Displacement Map Extraction options.)
- Normal Map (See Normal maps overview and Normal Map Extraction options.)
- Displacement Map (See Displacement maps overview and Displacement Map Extraction options.)
Extraction Options
Expand the following for options in each area of the Extract Texture Maps window.
Target Models
Displays the name of the model to receive the extracted map. The map produced will represent the difference between this model (low resolution) and the source model(s) (high resolution).
The target model is usually the lowest subdivision level of a model with multiple subdivision levels. You can click the displayed subdivision level (next to the target model name) to select a different subdivision level from a drop-down list.
Use the Add All, Add Selected, and Remove buttons to change the model listed as the target.
- Smooth Target Model
- Smooth Target UVs
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Smooths the positions of interior UVs of the target model during the texture extraction. Smooth Target UVs only smooths when the Smooth Target Model option is on.
This can be useful if your image rendering software (for example, Pixar’s RenderMan®) can smooth the UV texture coordinates on a mesh during rendering to improve the results.
- Use Creases & Hard Edges
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For target models with creasing or hard edge data (see Import and export objects with creasing and hard edges), lets you set how Mudbox handles the creasing information when extracting texture maps.
When on, Use Creases & Hard Edges affects the operation of other map extraction options. If you are smoothing your target mesh (Smooth Target Models is on), it ensures that the creases are maintained in the smoothed mesh. If you are using Ray Casting, it ensures that vertex normals are used to map the surface together (rather than face normals). If you are creating a normal map, it ensures that the local tangent space calculation takes the creases and edges into account, rather than interpolating smoothly over the model.
Source Models
Lists the model(s) to extract maps from. The source model (high resolution) typically contains the sculpted details to be extracted into the map(s). This model does not require UV texture coordinates.
You can click the displayed subdivision level (next to the source model name) to select a different subdivision level from a drop-down list. Use the Add All, Add Selected, and Remove buttons to change the model listed as the source
Method options
- Ray Casting
-
Extracts a texture map by recording the distance (as a pixel value) between the source and target models based on sample rays cast along the surface normals of the target surface. The number of sample rays cast depends on the texture map resolution.
Use this method when extracting maps between arbitrary meshes (meshes with differing topologies), and ensure that you manually align the models as accurately as possible before extracting. Artifacts in the resulting texture map can sometimes occur (particularly with overhanging features) that require editing afterwards.
- Subdivision
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Extracts a texture map by recording the distance (as a pixel value) between one subdivision level and the corresponding point at a higher subdivision level on the same model. Use this method only when extracting texture maps between different subdivision levels on the same model.
The resulting texture map will contain fewer artifacts compared to the Ray Casting method, requires no setup or alignment between separate models, and performs the extraction more quickly. However, Subdivision does not capture the height differences as accurately as the Ray Casting method, particularly when vertices on the higher subdivision level have been translated off normal compared to the lower subdivision level, which can occur when using the Grab or Pinch tools.
- Choose Samples
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(For map extraction, available only when Method is set to Ray Casting.) Controls how the extraction process matches points on the target model to points on the source model, and determines which value to record if an extraction sample intersects the high-resolution model more than once.
For example, given a target mesh with a relatively smooth surface (shown in cross-section in blue):
And using a source mesh with a detailed, wavy surface (shown in cross-section in black):
The following sections illustrate the Choose Samples options available.
- Search Distance
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(For map extraction, available only when Method is set to Ray Casting.) Sets the maximum distance samples can travel from the target model surface in search of a corresponding point on the source model surface. Samples can travel on both sides of the target model based on the Choose Samples option.
The Search Distance is a physical measurement that determines how far Mudbox searches to find sculpted detail on the source model(s). It should be slightly larger than the distance between the maximum absolute displacement between the high resolution (source) mesh and the low resolution (target) mesh. Click Best Guess if you are unsure.
If set too small, some detail will be cut off or flattened in the resulting map. If set too large, the resulting map can have precision errors, leading to jagged edges in the map. You may need to experiment with the Search Distance value and generate several maps to find the best results. See also Troubleshoot texture extraction.
TIP:To determine the distance between the source and target meshes, you can estimate the distance using the vertical line on the Sculpt tool that indicates the brush strength as a starting point. This line represents the distance the center of the tool moves the vertices in the current Mudbox units (the default is centimeters). - Best Guess
- Test Both Sides
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(For map extraction, available only when Method is set to Ray Casting.) Off by default. so that intersections are ignored when the ray intersects a surface that is facing in the opposite direction. When on, Mudbox records ray intersections with source faces that are backfacing. This improves extraction results when a number of intersecting meshes are used as the source model.
Image properties
(Available only when you set Map Type to Texture.)
- Generate one map for all targets
- Generate one map for each target
- Image Size
- Antialiasing
-
When on, improves the quality of the final extracted image map by applying a filter comparison between pixels in the image. Higher values increase the amount of antialiasing that occurs and the time to extract the image map. For initial test extractions, use a small Image Size value and leave the Antialiasing property turned off until you produce a final image.
PTEX resolution options
(Available only when you set Map Type to Ptex.)
Set these options to determine the number of texels in your final map, and how they are distributed across the mesh.
- Uniform
- Based on Face Size
- Based on UV Size
- Use PTEX Setup
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(Only available when the target mesh is set up for PTEX painting - see Prepare a model for PTEX painting.) Applies the same texel distribution you defined during PTEX setup.
Output options
Available when Map Type is set to Texture:
- Base File Name
-
Enter a name for the extracted map(s). To have Mudbox automatically append the target mesh name to your filename, use the wildcard characters %s.
IMPORTANT:If you are extracting a map for multiple target meshes and Generate a map for each target is on, ensure that you use %s as part of your Base File Name. (Otherwise the map generated for each target will have the same name and overwrite the map output for the previous target.)Click the browse icon
to set save options (including file format) in the Save As window. - Bits per Channel
- Preview as
Available when Map Type is set to Ptex:
- Include Mesh Data
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When on (default), Mudbox also saves general data about the mesh (vertex positions, list of faces, and so on) in the output PTEX file. This can be useful if other tools in your pipeline can use this type of PTEX data, for example if you will use a PTEX viewer to inspect the output file. It is recommended that you keep this option on when extracting PTEX files.
- File Name
- Data Format
-
Depending on the type of map (or maps) you're generating, lets you specify the bit depth for the extracted Ptex file. (Options include 8 bit integer, 16 bit integer, 16 bit float, or 32 bit float.) The larger the bit depth you select, the higher the precision in the extracted files, and the larger the file size.