Bakes selected objects with their respective bake set settings.
For more information on bake sets, see Bake sets.
For more information on a similar function in other renderers, see Edit > Convert to File Texture.
Lighting/shading > Batch Bake (mental ray) > 
If you select Select All from the Objects to Bake option, then all objects that are not assigned to the initial bake sets are baked.
For information about initial bake sets, see Assigning objects to bake sets.
Bake either textures or vertices. The default is Texture when you access this window through the Lighting/Shading menu. If you select vertices, vertices are baked in the same manner as Bake vertices.
Select Multiple objects to bake in the default light map mode. This baking method uses one thread per object. This method can give better performance for baking multiple objects.
Select Single object to use lens shader baking. The shape of the lens changes to be the same as that of your geometry. This baking method is multi-threaded and uses multiple threads for each object. This method can give better performance for baking a single complex piece of geometry.
Check this option to leave the current shading network intact.
If this option is unchecked, a file texture node will be created and attached to the object’s current shading network.
This option is only applicable if you bake to textures.
Regardless of whether this option is checked, a texture file is saved to disk.
Determines the maximum length of an occlusion ray. Rays longer than this value are not considered for occlusion.
For texture bake sets, if Final Gather is not used, occlusion is computed for all sample points. Although this takes time, the result is very sharp light maps. If Final Gather is used, and the final gather quality is greater than 0, the occlusion is pre-baked into a final gather map. This final gather map can then be interpolated during rendering providing quick results at a reasonable quality.
This option is on by default. When turned on, the Orthogonal Reflection option causes all reflection rays to be orthogonal to the surface being baked. They are no longer true reflection rays, pointing instead parallel to the surface normal vectors, but the resulting baked texture or vertex colors are meaningful when viewed later from any direction. This option should be turned on if the textures or vertex colors generated are to be used as textures in a game engine.
Turn this option off if you are baking in order to accelerate software rendering and the reflections are only viewed from the baked position. However, in this case, the textures or vertex colors generated are not for use as textures in a game engine.
Determines the final gather precompute quality. When rendering from the camera, mental ray precomputes a final gather pass before actually rendering the scene. This precomputation pass is disabled by default for baking.
When this attribute is set higher than zero, mental ray computes a number of final gather points before it bakes the lightmap. When this attribute is set to one, the resulting lightmap should be of approximately the same quality as a lightmap rendered from the camera. When this attribute is set higher than one, then the quality of the lightmap is improved as a denser map of final gather points is precomputed.
Do not use this option to tune final gather quality for baking. Final gather quality affects the number of points calculated at the precomputation phase of the final gather algorithm. By increasing the final gather quality, you are only creating more points during precomputation and possibly reducing the amount of interpolation or extrapolation required during rendering. Increasing the final gather quality does not affect the accuracy of the light calculated for each point or the filtering that is used on the data.
Instead, adjust the Scale in the Render Settings Window. This attribute controls the accuracy of the light calculated for each final gather point. Adjust also the View (Radii in Pixel Size). This attribute controls how data is interpolated/extrapolated between final gather points.
Determines the reflectivity of an object when precomputing final gather points for light mapping. This simplifies the simulation of reflective objects whose texture maps include contributions from objects that surround them. For example, if the Final Gather Reflect value is set to 0.25, every fourth final gather point is precomputed on the object hit by the reflection ray.
If the selected UV space contains boundaries, these boundaries may appear as black stripes in renderings that use the baked textures. This occurs when the texture is sampled so close to a boundary that the filter picks up values (generally black) from outside the desired space.
This setting artificially extends the boundaries by a small amount to alleviate this problem. It is measured in texels (pixels of texture). Typically, the filter is only a few texels in diameter and can only reach as far as its radius into these boundary spaces, so a value of 1 or 2 is usually enough.
This option is on by default. When turned on, the Orthogonal Reflection option causes all reflection rays to be orthogonal to the surface being baked. They are no longer true reflection rays, pointing instead parallel to the surface normal vectors, but the resulting baked texture or vertex colors are meaningful when viewed later from any direction. This option should be turned on if the textures or vertex colors generated are to be used as textures in a game engine.
Turn this option off if you are baking in order to accelerate software rendering and the reflections are only viewed from the baked position. However, in this case, the textures or vertex colors generated are not for use as textures in a game engine.
If final gathering is baked to vertices and the scene contains high frequency information, discontinuities in the color channel may become visible. This artifact becomes especially apparent if low final gather quality settings are used. Filtering baked vertex colors yields the desired smooth look.
Provide a small positive filter size as argument to this parameter (it is multiplied by the object's bounding box size to obtain the absolute size). Set the Filter Size value to -1 to turn filtering off. Set the value to 0 or larger to turn it on.
Start with values in the 0.1 range as this value is multiplied by the object’s bounding box size to obtain the absolute size. This process also allows smaller values to be used for the Accuracy attribute in the Render Settings: mental ray tabs (Indirect Lighting tab > Final Gathering section) for faster performance although accuracy of results may need to be taken into account.
Lower final gather quality settings require larger filter sizes to get a smooth look and renders are less accurate. In general, the final gather quality should be raised as long as rendering times are acceptable; then the filter size should be increased until the desired smooth look is obtained. A tiny filter size may suffice; it enforces that baked colors are shared at vertices which have identical positions and normals.
The filter normal tolerance in degrees (0 to 180).
This lets you adjust the angular tolerance for smoothing value across faces.
Vertices whose angular separation is greater than the entered value are not taken into consideration for filtering so that crisp transitions are maintained across hard edges, and undesired color bleed doesn’t occur.
After adjusting this option, repeat the prelight operation to test. When a fairly smooth result is obtained, use the Filter Size to adjust further.
