For an overview of ambient
occlusion maps, see
Texture extraction overview.
- Select Maps
> Extract Texture Maps > New Operation.
The Extract
Texture Maps window appears. For a complete description
of extraction properties see
Extract Texture Maps properties.
- Select Ambient Occlusion Map in
the Maps to Generate section.
- Indicate the model(s) you want an ambient
occlusion map for by selecting its name in the Target
Model section.
NoteIf a model is not
selected then an ambient occlusion map is produced for all objects
in the 3D View. Keep in mind that
all visible objects in the 3D View are taken
into account when calculating an ambient occlusion map. That is,
if you don’t want an object to be included as part of the ambient
occlusion calculations, hide it before extracting a map.
- Set the desired subdivision level for
the target model(s) that you want the extraction to occur on by
stepping up or down using the Page Up or Page Down keys.
Setting the subdivision
level on the target model to the highest subdivision level provides
the highest detailed ambient occlusion maps possible. You can extract
an ambient occlusion map at lower subdivision levels, but fine detail
will be lost and the appearance of facets may result because of
the reduced resolution.
- In the Output Map window,
adjust any properties as required (described below) and then click Extract.
NoteThe model must have
UV texture coordinates to extract an ambient occlusion map. Otherwise,
the following message appears when you click
Extract:
The model mesh has no UVs. Mudbox needs UVs
to generate Ambient Occlusion Maps. Try selecting Recreate Level
UVs under the Mesh menu. For more information, see
UVs overview.
- Image Size -
Specifies the height and width (in pixels) of the ambient occlusion
map(s) output.
- Quality - Determines
the quality of the final ambient occlusion map based on multiple
shadow maps that get used for the calculation.
- Base File Name -
Specifies the name of the extracted map(s).
- Add as Paint Layer -
Automatically imports the generated ambient occlusion map as a new
paint layer within the Diffuse channel
of the assigned material. Turn this setting off if you don’t want
the ambient occlusion map assigned to a new paint layer.
TipThe first time you
extract an ambient occlusion map, set the Quality setting
to Fastest and Image
Size to a small resolution to quickly generate a test
map. Evaluate this initial test, adjust any settings as required,
and then set the Quality and Image
Size options to the final settings before generating
a final map.
The Advanced section
of the Extract Texture Maps window,
contains the following properties when Ambient Occlusion Map is
selected:
- Shadow Map Resolution -
Controls the size of the shadow maps for the occlusion map calculations.
- Shadow Darkness -
Controls the darkness of the shaded regions in the final ambient
occlusion map.
- Shadow Contrast -
Controls the contrast between shaded and non-shaded areas in the
ambient occlusion map.
- Filter - Controls
the filtering of the multiple shadow map calculations when producing
the final ambient occlusion map. To achieve sharp, finely detailed shadows,
set the Filter value to a low number (0.0001).
To produce a softer effect, set the Filter value
to a higher number.
A progress bar on the Status
Line indicates the progress of the extraction. Depending
on the Quality setting, this bar may
repeat the process several times as the feature calculates and composites
the necessary shadow maps.
The ambient occlusion
map is automatically applied to the model(s) as a diffuse paint
layer (provided the Preview as Paint Layer property
is turned on) and positioned on top of any other existing paint
layers in the Diffuse channel.
If the model contains
UVs within multiple UV tile spaces, that is, outside the 0 to 1
range, the feature automatically creates separate ambient occlusion
maps that correlate to each UV tile and saves them to the user-specified
directory.
NoteIf your model contains
multiple UV tiles, each tile will appear in a different color after
the ambient occlusion map is applied to indicate that the textures
are currently unloaded. This is a graphics memory optimization feature. For
more information, see
Hide and show UV tiles on a model.
Edit an ambient occlusion
map
Once an ambient occlusion
map has been created and applied as a visible paint layer, you can
evaluate it and then make successive iterations by changing the
extraction settings then clicking extract, and previewing the updated
version again.
If you extract successive
ambient occlusion maps with the same file name it overwrites the
previous one and the paint layer is automatically updated in the 3D
View with the new map.
You can use the Paint tools
to modify or enhance the ambient occlusion map (add shading, erase
shading, and so on) because the map is applied a diffuse paint layer.
For more information, see
Painting.