Maya FBX Plug-in Guide - S.alias

2 Importing and ExportingThe FBX Exporter window appears (figure 2-1). Select the optionsthat apply to your scene.figure 2-1: FBX ExporterwindowFor more information about the FBX Exporter window options, see"FBX Exporter window options" on page 7.Maya FBX Plug-in Guide66Click Export. The exporter window shows the progress of the exportprocess.7Open the file in MotionBuilder or another 3D package.8If you are using MotionBuilder, when you are finished, merge theanimation from all layers with the Base layer using the Layers panein the FCurves window.

2 Importing and ExportingFBX Exporter window optionsOnce you select an FBX file to export from Maya, the FBX Exporterwindow appears (figure 2-2).figure 2-2: FBX ExporterwindowThe FBX Exporter window contains the following export options:OptionDescriptionFileShows the path of the file selected for export.UnitsShows the unit of measurement used by thesoftware and its conversion factor.Apply Constant KeyReducer FilteringDeletes any redundant keyframes.Resampling Frame RateSets the rate at which the exporter produceskeyframes when it needs to resample data.Resampling is needed when the interpolation ofthe Maya animation curve cannot be accuratelyrepresented by curves in MotionBuilder,MotionBuilder Professional, or Alias MoCap.Maya FBX Plug-in Guide7

2 Importing and ExportingOptionDescriptionExport Animation OnlyExports the animation.Export Hard EdgesDuplicates polygon edges and normals to createthe effect of hard edges.Export ConstraintsIncludes constraints in the file on export.When this option is disabled, the export processignores all the constraints defined in the Mayascene and does not include them in the .fbx file.The default setting is active.Export CharacterDefinitionMaya FBX Plug-in Guide8Includes Character Definition in the file on export.When this option is disabled, the Characterdefinition in the Maya scene does not export tothe .fbx file. This option is only available in theMaya FBX Plug-in for Maya 7.Embed TexturesCopies the texture and material files associatedwith the file into the .fbx file, so that they are notreferred to from the hard disk.Portable formatConverts your textures into .tiff format, whichmakes textures readable on other platforms.Export in ASCII formatSaves the .fbx file in ASCII format.ExportStarts the export process.CancelCloses the FBX Exporter window, withoutperforming any action.

2 Importing and ExportingImporting .fbx files into MayaNoteTo increase the transfer speed of the import, triminsignificant weights on deformed models withMaya’s Skin Edit Smooth Skin Prune SmallWeights command.1In Maya, select File Import. A file browser appears.2Select Fbx as the file type.Note3If you do not select FBX as the file type, MAC OS Xsystems will run the image viewer “FCheck”program instead of loading the file.Locate the .fbx file that you want to import.Maya FBX Plug-in Guide9

2 Importing and ExportingThe FBX Importer window appears (figure 2-3).figure 2-3: FBX Importerwindow4Activate any options that apply to your scene.For information about the options in the FBX Importer window, see"FBX Importer window options" on page 11.5Maya FBX Plug-in Guide10Click Import.

2 Importing and ExportingFBX Importer window optionsOnce you select an .fbx file to import into Maya, the FBX Importerwindow appears.figure 2-4: FBX ImporterwindowThe FBX Importer window contains the following import options:OptionDescriptionFileShows the path of the file selected for import.Maya FBX Plug-in Guide11

2 Importing and ExportingOptionDescriptionTake windowDisplays the takes included in the scene. Click atake to select it for import. You can only selectone take at a time.Exclusive MergeTransfers animation into nodes that exist in boththe current Maya scene and the .fbx file.No new nodes are created.Add to New SceneImports your data into a new scene.MergeMerges the imported .fbx file to the current sceneby creating any node without its equivalent in thescene.Nodes with the same name but not of the samenature, for example, sphere and bone, arereplaced.Nodes with the same name and nature only havetheir animation replaced.Convert Quaternoin Rotations as:Leave as QuaternionsTransfers Quaternion interpolation flags toMaya’s FCurves whenever the Maya FBX plug-inencounters rotation curves marked to beinterpolated.Convert to EulerDoes not transfer Quaternion interpolation flagsto Maya’s FCuves, and instead interpolates theFCurves in Euler space whenever the Maya FBXplug-in encounters rotation curves marked to beinterpolated.Resample as EulerResamples rotation curves in the Quaternionspace, transfers the resulting curves to Maya asEuler curves.Use this method if you are experiencing problemswith Quaternion curves inside Maya.Maya FBX Plug-in Guide12

2 Importing and ExportingOptionDescriptionDetected DestinationWorld Unit:Shows Maya’s current units. For example, if Mayais set to display in inches, this seting displays:1 centimeter 0.3937000 inchesThis way, keyframe values or vertex positions arescaled accordingly, so if you translate a 1centimeter object, it moves 0.3937 units if Mayais set to inches.Pre-Normalize WeightsActivate this option if you notice unusual skinweighting, as this conforms the .fbx file’s weightsto Maya’s conventions.Depending on the size of your scene, this processcan take several minutes.Import ConstraintsImports all constraints into the new scene.When this option is disabled, all the constraintsdefined in the .fbx file are ignored by theimporting process and are not present in theMaya scene.The default setting is active.Import CharacterDefinitionImports Character Definitions into the scene.When this option is disabled, the Characterdefinition in the .fbx file is not imported into theMaya scene.This option is only available in the Maya FBX Plugin for Maya 7.Convert IncomingDeforming Nulls toJointsConverts deforming nulls into Maya bones.This option was originally provided because Mayadid not support null elements (that is, transformnodes that are not joints,) within a bonehierarchy).While Maya now supports this, in some casesthis option improves the skinning behavior.Maya FBX Plug-in Guide13

2 Importing and ExportingOptionDescriptionMerge Pivot Nodes asRotate Axis and JointOrientActivate this option only when you use older .fbxfiles.Assigns the rotation transformation of the null (orjoints) elements in the hierarchy that are used aspre- and post-rotation to the joint orient and therotate axis of the original node.The pre-rotation and post-rotation nodes are thendeleted. Older files created with the Export Pre/Post Rotation as Nulls option are merged back tothe original Maya Setup.Import Hard EdgesMerges edge duplication previously created bythe FBX export action “Export Hard Edges” tocreate Maya hard edges.Activating this option undoes the FBX exportaction "Export Hard Edges" on page 8.Protect Driven KeysPrevents any channels with driven keys frombeing overwritten by the incoming animation.Merge Animation LayersComputes the effect of all animation layers andtransfers the resulting animation to Mayawhenever multiple layers of animation are used.Resampling Frame Rate(fps)Sets the rate at which the importer produceskeyframes when it needs to resample data.Resampling is needed when the interpolation ofthe Maya animation curve cannot be perfectlyrepresented by curves in MotionBuilder,MotionBuilder Professional, and Alias MoCap.Maya FBX Plug-in Guide14ImportBegins the import process.CancelCloses the FBX Importer window, withoutperforming any action.

2 Importing and ExportingWhat’s supported in the Maya FBX plug-inThe Maya FBX plug-in supports the following Maya functionalities: Maya Point, Orient, Scale, Parent, Chain IK, Aim and Characterconstraints Full Body IK NURBS and Polygons Skeletons Cluster deformations, Smooth and Rigid bindings User attributes File texturesTexture mapping is converted as UV Maps. Texture placement androtation is supported. Pivots LightsIntensity value, animation, as well as color value and animation issupported. CamerasSqueeze ratio, Near and Far plane values, Aperture width, Height,FOV, and Focus Length. Simple materialsPhong type materials are supported. Blend Shape deformationsMaya FBX Plug-in Guide15

2 Importing and ExportingSupported, provided that the target is not deleted. Blend Shapechannels must already have at least one key set when an .fbx fileis merged back. Blend shape weights are ignored on export, andare not changed on import.NoteThe Maya FBX plug-in only supports Blend Shapesthat have a “Deformation Order” that is upstream,that is, Before, FrontOfChain or Default.What’s not supported in the Maya FBX pluginThe Maya FBX plug-in does not support the following Maya features: Procedural textures Trims or NURBS Booleans DeformersDeformers other than clusters, or Smooth or Rigid binding, are notsupported. Subdivs CurvesCurves show up as nulls (locators) in MotionBuilder, MotionBuilderProfessional, and Alias OnLine. Expressions, Driven Keys and Constraints. GroupsYou can instead parent the geometries. Use File Textures and Polygon projectionsBake (Hypergraph Convert to File Textures) any proceduraltextures (Grid, Ramp, and so on) that have a UV rotation (Place 2Dtexture node).Maya FBX Plug-in Guide16

2 Importing and ExportingIn MotionBuilder, MotionBuilder Professional, and Alias OnLine, theUV rotation has a corner pivot instead of Maya’s center pivot.What’s newThe following section contains the new features, bug fixes, and knownlimitations for this version of the Maya FBX plug-in:New features String attributes are supported and saved. The appear as FBX LISTtypes and becomes a list that contains a single element whenimported back into Maya. You can now save .fbx files in ASCII format by selecting the Exportin ASCII format option in the FBX Export dialog box.Bug fixes A problem with reading and writing to and from Network drives onWindows 32-bit systems with the \ server . file path format(where server is the name of the remote machine beingaccessed) has been corrected. Problems with exporting skin whenever smooth operators arefound have been eliminated. The smoothness settings are set to 0so the saved skin information and the imported mesh areconsistent. Files containing deformed meshes that are modified by a smoothoperator can now be imported properly. This lets you import older.fbx files saved with a previous versions of the Maya FBX plug-in. Normals on skinned objects can now be exported properly. A problem with blendshapes that causes models with hard edgesto deform incorrectly in MotionBuilder has been fixed.Maya FBX Plug-in Guide17

2 Importing and Exporting You can now correctly transfer the candidate of the Parent-Childconstraint. The rest position set in the constraint now sets theposition of the object instead of the position of the object at thecurrent time when you export the scene.NoteThis is used only when the constrained object isnot animated, and the RestEnable value isactivated for the constraint in Maya.Known limitationsThis section lists the known limitations of the Maya FBX plug-in: Scaling and rotation on clusters may not behave as expected. Maya constraints that have prefixes in their names do not exportcorrectly. Try to remove the prefix of any Maya constraints. The Visibility FCurve adjusts itself to contain a value of only 0 or 1.Also the FCurve is converted to Constant (step) interpolation.Therefore, any value above 0 is considered as 1 (visible) and anyvalue below or equal 0 is considered 0 (invisible).When exporting, if the Tangent type is Slow or Fast, the Maya FBXplug-in resamples FCurves. They are also resampled if theOutTangent is Linear and the InTangent is different, or theOutTangent is Flat, Smooth, or Fixed and the InTangent is not Flat,Smooth or Fixed. Nurbs display precision is supported and exported as StepU andStepV parameters in MotionBuilder, MotionBuilder Professional,and Alias OnLine. Both U and V are assigned the same value; asin Maya, its value is unique. Values of the Precision parametersare clamped to a maximum of 15 (the software’s limit).NoteMaya FBX Plug-in Guide18When importing, the larger value between StepUand StepV is used.

2 Importing and Exporting When Shape objects (used in the Blend Shape) have the samename as other objects in the scene, the name-clashing solver canbehave erratically. Avoid this by using different names for models. Maya's Ambient lights are not supported and are exported as Nullobjects. Area lights are exported as a Point lights. The Maya FBX plug-in is only capable of processing upstreamBlend Shape deformers, for example, the Default, Front of Chain,and Before modes. MotionBuilder Animation Layers are not supported in Maya. You cannot redirect animation from one character to another(known as “character retargeting” in MotionBuilder,) in Maya. Full Body IK does not respect joint limits. The renaming strategy is used for two scenarios, multipleinstances with the same name, and Upper/Lower case conflicts.Multiple instances that have the same name:In this case, a symbolic code is used. The Maya FBX plug-in can readolder files, although it no longer writes them this way.The new suffix is then: ncl1 X (where X is the instance number).Upper/lower case conflicts.In this case, the suffix is more complex as it has to keep track ofwhich character was/is upper/lower case so it can convert it back onimport/merge.The following suffixes are used to indicate the case:Indicates case:ncl2Marks characters that were originally upper case and havebecome lower case:ulXXXXMaya FBX Plug-in Guide19

2 Importing and ExportingMarks characters that were originally lower case and havebecome upper case:luXXXXWhere XXXX is an integer number that represents the characterposition in the string (bitwise). For example, ul5 indicates that thefirst and third characters in the string have been changed from upperto lower case. A suffix can be made of the combination of ul and lusub-suffixes.Maya FBX Plug-in Guide20

3Maya MEL ScriptingThis section contains scripts required for scripting with Maya MELcommands.All of the Maya FBX plug-in's MEL commands begin with the FBX prefix.When error conditions are encountered, they will display errormessages in the Script Editor window. The MEL commands that areregistered by the Maya FBX plug-in are listed in the Plug-in Managerinformation dialog box.NoteTo use the following MEL commands, the MayaFBX plug-in must be installed on your computer.FBXExport -f [filename]Exports the specified file. If FBXExportShowUI is True, the Export dialogbox is shown.FBXExportShowUI -v [true false]TrueDisplays the Export dialog box each time user clicks File Export oruses the FBXExport MEL command.FalseNever displays the Export dialog box. The only way to have the Exportdialog box displayed again is to set this flag to “True” by using thisMEL command or by checking the appropriate check box in the Batchdialog box.Maya FBX Plug-in Guide21

3 Maya MEL ScriptingFBXExportHardEdges -v [true false]TrueDuplicates all vertices in the scene's meshes for each polygonconnected to them. The vertices’ normals are set accordingly,depending on whether they are connected to a hard or smooth edge.NoteThis function allows MotionBuilder to display hardedges.If two vertices are located exactly at the same position, a warning isissued, as this causes unpredictable results whenFBXImportHardEdges is set to True.FBXExportConstraint (-v true false)Causes all the constraints defined in the Maya scene to be ignored bythe exporting process, and excluded from the .fbx file.FBXExportCharacter (-v true false)Causes the export of Character definition in the Maya scene to beexcluded from the .fbx file.NoteMaya FBX Plug-in Guide22This option is only available in the Maya FBX Plugin for Maya 7.

3 Maya MEL ScriptingFBXExportApplyConstantKeyReducer -v[true false]TrueFilters FBX animation FCurves through a Constant Key reducer. Thiseliminates constant keys on a FCurve and helps to reduce the size ofresampled FCurves, especially Scale.FalseSetting this command to False ensures that the animation data is notfiltered.FBXExportEmbeddedTextures -v [true false]TrueSaves all textures in the FBX file. This command performs the sameaction as the Embed Textures option in the FBX Exporter window.FBXImport -f [filename] -t [take index]Imports the specified file. If FBXImportShowUI is True, the Importdialog box is shown.The file imported is the one accessible for take querying after theexecution of the command.FBXImportShowUI -v [true false]Once FBXImportShowUI is set to False, the user interface does notappear until FBXImportShowUI is set to True.There are two possible states:Maya FBX Plug-in Guide23

3 Maya MEL ScriptingTrueShows the Import dialog box each time you click File Import or use theFBXImport MEL command.FalseHides the Import dialog box. The only way to show the Import dialogbox again is to set this flag to “True” with this MEL command or bychecking the corresponding check box in the Batch dialog box.FBXImportHardEdges -v [true false]TrueMerges back all vertices located at the same exact position as aunique vertex. The Maya FBX plug-in then determines if the edgesconnected to each vertex are hard edges or smooth edges, based ontheir normals.Use this function when FBXExportHardEdges is set to True on export.FBXImportConstraint (-v true false)Causes all constraints defined in the .fbx file to be ignored by theimporting process and excluded from the Maya scene.FBXImportCharacter (-v true false)Causes the import of the Character definition in the .fbx file to beexcluded from the Maya scene.NoteMa

Maya FBX Plug-in Guide 1 1 Installation The Maya FBX plug-in is used by Maya to import, export, and convert files using the .fbx file format. This chapter describes how to install the Maya FBX plug-in on Windows , Mac OS X, and Linux systems. The Maya FBX plug-in comes with Maya and is