Show frames
Go to: Synopsis. Limitations. Return value. Related. Flags. MEL examples.
convertLightmap [-bakeSetDefault string] [-bakeSetOverride string] [-camera string] [-exportPathNames string] [-file string] [-help] [-miStream] [-notUndoable] [-project string] [-separator string] [-shadows] [-transferMapSpace string] [-useLensBake] [-vertexMap]
string object [string object ...]
convertLightmap is undoable, NOT queryable, and NOT editable.
Calculating global illumination is an expensive and time-consuming
task that denies its usage in realtime rendering. As long as the
lighting conditions in scenes do not change, illumination on objects
can be precomputed and stored in appropriate data structures, like
texture maps or vertex colors. These can then be applied in realtime
applications like hardware rendering and game engines.
The Lightmap Rendering feature allows to prerender surface color or
surface lighting (including global illumination) into file textures
and per-vertex colors, respectively, on a per object basis. These file
textures can then be used as regular texture maps to speed up
subsequent software renderings and to apply the precomputed rendering
effects even to hardware rendering.
For the purposes of baking and prelighting, mental ray for Maya
supports the convertLightmap command.
Any given shading group must be assigned to (some components) of the
given object. Any number of shading group - object combinations can be
given. The given object should uniquely identify a single instance of
a single shape node. If just a transform name or a shape name is
given, the command will try to determine the first child shape or
instance parent. If a single object should be baked that has multiple
materials assigned (per-face assignment on mesh objects, per-instance
assignment on multiply instanced shape nodes) then every shading group
has to be provided separately referencing the same object. On the
other hand, if the same material has been applied to multiple objects
(shared materials) then this shading group needs to be given multiple
times for all of the objects.
Besides the command flags, per-object settings are set through bakeset
of each object. If an object does not have a bakeset, and -bo flag is
not specified, default settings for a bakeset will be used. See node
reference of TextureBakeSet and VertexBakeSet
The lightmap rendering is done with the render quality currently set
in the mental ray render globals. Especially, photon tracing and/or
final gathering should be enabled to compute global illumination that
will be considered during lightmap generation. But certain limitations
apply to the current implementation:
- motion blur may not appear in lightmaps
- volumes and fog are not recognized in lightmaps
- the alpha channel is always rendered into file textures
| string[] | The command returns an array for string values of exactly the same
length as bake combinations have been given. The returned string
contains the name of the baked object (either texture file name or
vertex bake object) upon success, or the string "error" otherwise. |
Mayatomr
bakeSetDefault, bakeSetOverride, camera, exportPathNames, file, help, miStream, notUndoable, project, separator, shadows, transferMapSpace, useLensBake, vertexMap
| Long name (short name) |
Argument types |
Properties |
|
-bakeSetDefault(-bd)
|
string
|
|
|
Specifies a bake-set to include all objects not assigned to any other bake-set in the scene.
|
|
-bakeSetOverride(-bo)
|
string
|
|
|
If this parameter is given, the specified bakeset will be used instead of bakeset of each object.
|
|
-camera(-cam)
|
string
|
|
|
Which camera to use for computing the direction of the incident ray.
Default: current render camera
|
|
-exportPathNames(-xp)
|
string
|
|
|
Export option for the file references such as : ink library, include mi file, texture file,
lightmap, etc.
The string can specifies an for individual file refs, with
each character in the string representing a single file ref
entry, with meaning
0-nochange 1-absolute 2-relative 3-nopath, or
0-nochange a-absolute r-relative n-nopath.
The file ref entry is specified in this order :
link library, include mi file, texture file, lightmap, light profile,
output image, shadow map, finalgather map, photon map, demand load object mi file.
Effective only if -mi/-miStream flag is present.
Default: nochange
For example, "-xp aarrararra" will use absolute path for
link libray, include file, light profile, shadow map, demapd load object mi file,
and relative path for
texture file, lightmap, output image, finalgather map, photon map
|
|
-file(-f)
|
string
|
|
|
Specifies the absolute file name of the mental ray file to be generated.
Effective only if -mi/-miStream flag is present.
|
|
-help(-h)
|
|
|
|
Prints a verbose help message.
|
|
-miStream(-mi)
|
|
|
|
If this parameter is given, besides the lightmap rendering,
the command generates a mental ray file that can be used with mental ray standalone. -f/-file flag must be specified.
|
|
-notUndoable(-nun)
|
|
|
|
If this parameter is given, the command can not be undone.
|
|
-project(-prj)
|
string
|
|
|
Set the project directory.
If baking to a light map, light maps will be generated into "lightMap" sub directory in the project.
If "lightMap" directory does not exist, the command fails to write light maps.
Default: current project root directory
|
|
-separator(-sep)
|
string
|
|
|
If this parameter is given, baking will use this string to separate instance and shape name parts
when generating unique file names for complex dag objects (dag instances with multiple shapes, or hierarchical dag entries).
Default: no separator.
|
|
-shadows(-sh)
|
|
|
|
Take shadow into account.
If shadow is disabled in the mental ray render globals,
mental ray for maya will enable the shadow map, and shadow method segments will be turned on.
|
|
-transferMapSpace(-ts)
|
string
|
|
|
Use for transfer map operation only.
Specify the map space. "world" or "object".
Default: world
|
|
-useLensBake(-ulb)
|
|
|
|
Special texture bake mode, which uses a lens shader to shape the lens
to the object. Not valid with the -vertexMap flag. Best suited to baking
a single large object.
|
|
-vertexMap(-vm)
|
|
|
|
Bake illumination into vertices. If not present bake into a light map.
|
|
|
Flag can appear in Create mode of command
|
Flag can appear in Edit mode of command
|
Flag can appear in Query mode of command
|
Flag can be used more than once in a command.
|
// Bake a texture for |pSphere1|pSphereShape1 using the 'persp' camera and the initialShadingGroup.
// This uses the bakeset assigned to |pSphere1|pSphereShape1.
convertLightmap -camera persp -sh initialShadingGroup |pSphere1|pSphereShape1;
// Generates a mental ray file that can be used with mental ray standalone.
// Texture files exported with absolute path, and all other file entries
// are exported with no path.
convertLightmap -mi -file "C:/Dev/bake.mi" -xp "331333333" -camera persp -sh initialShadingGroup |pSphere1|pSphereShape1;
// Bake to verticies for |pSphere1|pSphereShape1 using the 'persp' camera and the initialShadingGroup.
// This uses the bakeset override tmpVerticesBakeSet.
convertLightmap -camera persp -sh -vm -bo tmpVerticesBakeSet initialShadingGroup |pSphere1|pSphereShape1;