What are ambient shadows?

When ambient shadows are applied to a scene, it looks more realistic, with shadows added to corners and other dark areas of the scene. These shadows are the result of occlusion, or the blocking of objects by other objects.

When you bake (apply) ambient shadows onto a surface, they will darken the surface, regardless of which material is later applied to the surface. Because ambient shadows have this darkening effect on the look of materials, it is recommended you bake the ambient shadows before fine-tuning the look of materials.

Ambient shadow calculations are by default based on object parameterization. For best results, make sure imported objects contain no overlapping vertex parameter values.

Performance warning

Calculating ambient shadows can take a long time for a large complex model. For the most efficient workflow, experiment with a small and easily visible piece of a model to make sure that ambient shadowing provides the effect you are looking for. Then make sure you are calculating ambient shadows on visible parts only. Calculations can be interrupted if they are taking too long, but no shadows will be applied.

Include ambient shadows in a scene

1. Select Edit > Show Normals to make sure that normals are facing outward.

   (If normals are not facing outward, unpredictable results may occur.) Check surface normals

2. To speed up the calculations, select only those parts of the model for which you want to calculate ambient shadows.

   For example, you do not need to create ambient shadows for bright parts of the model that do not have crevices, holes or occluded parts. Decals and transparent objects such as glass should also be excluded to make sure they do not occlude the surfaces underneath. To avoid making an interior too dark, exclude the roof or cover before calculating ambient shadows.

3. Select Scene > Create Ambient Shadows.
4. The Create Ambient Shadows window appears.

   

   For most situations, the preset settings should be adequate. Use the faster shadow presets for faster calculations (but less quality); the slower presets for higher quality.

   As you refine your scene and want to lighten dark areas, you may wish to customize the settings in this window. See Advanced ambient shadows settings.

   (Select Default Settings to return to the default (recommended) settings.)

   To avoid a patchwork appearance, do not use different settings for adjoining surfaces of your model.

5. Select Use environment floor to include the floor in the ambient shadow calculations. The floor generally absorbs light, giving the scene a slightly darker, more realistic look.
6. If you want to use vertex-based ambient shadows calculation, select Compute per vertex.
7. Click Create.

   The program begins calculations to create the ambient shadowing. Do not try to use the software until this process is finished.

Verify ambient shadow maps

To see ambient shadows maps:

1. Select Scene > Show Ambient Shadows Only.

   The materials disappear so that you can see which objects have ambient shadows calculated for them.

   NoteAny ambient shadows are shown as grayscale, though materials applied to the surfaces may alter the color with the “Self-shadow color” parameter. (See Color parameters for more information.)

   

   The darker areas show where ambient shadows are strongest (for example, the wheel wells in the image above). The white areas show where they are not applied.

   NoteIf the original materials remain in the scene, there are no ambient shadows applied to any surfaces.
2. Select Scene > Show Ambient Shadows Only to see the materials again (and edit your scene).

Adjust ambient shadowing for individual surfaces

To lighten up or darken particular surfaces with ambient shadowing already applied to them:

1. Select the surfaces you want to adjust.
2. Select Scene > Adjust Ambient Shadows.

   The Adjust Ambient Shadows window appears.

   

3. Move the slider to the left to lighten the ambient shadows.

   Or, type a value larger than 100 into the field to darken the ambient shadows.

4. When you are finished, close the window.

Adjust ambient shadow color by material

Each material can override the color of the ambient shadowing that is applied to it. This can both lighten and colorize the effect of the ambient shadows by material assignment.

To set the Self-shadow color:

1. Select the object with the intended material assigned to it.
2. Press Ctrl+M (or select Material > Material Properties) to open the Material Properties window.
3. In the Color section, change the Ambient shadow color by clicking on the color swatch or adjust the overall brightness by adjusting the slider.

   

   This color filters the color and brightness of any Ambient Shadows on the object that the material is applied to. (Black = default black ambient shading, White = no ambient shading visible, Color = colored ambient shadows on top of the current material)

   For details on how to create and edit Materials, see Material property parameters.