General Event Callback Mechanism

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Adding Callbacks Removing Callbacks Inspecting Callbacks Additional Notification Information on the Callback ActionItem Notifications Animation Notifications Render Dialog and Render Plugin Notifications Image Viewer Display Notifications Rendering Notifications File Link Notifications File Notifications Xrefs Notifications Layer System Notifications Manipulate Mode Notifications	Modifier Panel Notifications Modifier Notifications Material Library Notifications Material Notifications Node Related Notifications Plug-in Notifications System Notifications Radiosity Notifications Undo System Notifications Schematic View Notifications Named Selection Set Notifications Direct3D Notifications Other Notifications

Adding Callbacks

The callbacks are added using the following syntax:

callbacks.addScript <callback_type_name> (<script_string> | <script_stringstream> | fileName:<filename_string>) [id:<name>] [persistent:<boolean>]

This method is used to register a new callback script. Requires as the first argument a name that specifies which type of notify event this script is associated with. The list of valid callback_type_name values is listed below.

The script is supplied either as a direct String or StringStream value containing the text of the script to run, or as a fileName: keyword argument, in which case the named file is loaded and run whenever the event notification callback occurs. You can specify either a direct string or a fileName: , but not both.

The optional id: parameter lets you tag one or a group of callbacks with a unique name so that you can remove them all as a group without interfering with other callbacks, perhaps registered by other scripted tools.

The optional persistent: parameter lets you control whether the script is saved permanently in the currently open scene file or is a global callback script that remains in place no matter what file opening and closing is performed. A true value for the parameter specifies that the script should be stored in the current file and loaded and registered for callback whenever that file is opened again. Persistent callback scripts are always removed when a new file is loaded or a reset is performed so that persistent scripts in one file don't accidentally get copied to a later file. The default for this parameter is false , indicating the script is a global script and is not persistent.

EXAMPLE:

callbacks.addScript #preRender "setUpRenderGeom()" id:#jbwRender

This registers a new callback script that will be called just before a render is performed. The script invokes a function (that has presumably already been set up). A unique ID has been assigned to the script for later selective removal.

Removing Callbacks

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callbacks.removeScripts [<callback_type_name>] [id:<name>]

This method is used to unregister and remove one or more callback scripts.

Specifying just a callback event type name removes all the callback scripts for that event type.

Specifying just an id: removes all callback scripts in all events with that ID.

Specifying both limits the ID-based removal to the specified event type.

Inspecting Callbacks

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callbacks.show [<callback_type_name>] [id:<name>] [to:<stream>]

This method lists out the current callback scripts in the Listener window.

If the optional callback type name argument is specified in 3ds Max 2009 and higher, only callbacks of that type will be shown.

If the optional keyword argument id: is specified, only callbacks with that ID will be shown.

If type name and ID are both specified, only callbacks of the type with the given ID will be shown.

New in 3ds Max 2018.4 Update: If the optional keyword argument to: is specified, output from the method is sent to the specified stream.

callbacks.broadcastCallback <callback_type_name>

This method provides a way for you to simulate one of the events and have all the callback scripts for it executed.

Within 3ds Max, the #preRenderFrame and #postRenderFrame callbacks can only be called by the renderer. These callbacks can not be called by using this method.

Additional Notification Information on the Callback:

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callbacks.notificationParam()

This method can be called in a callback script to provide additional information on the callback. The value returned by this method varies based on the callback type. If no additional information was present for the callback, a value of 'undefined' is returned.

EXAMPLE:

--Remove any existing callbacks with this ID.
callbacks.removeScripts id:#MXSHelp
--Add a new callback script which will call
--callbacks.notificationParam() before selected nodes are deleted
--and thus will print the deleted objects to the Listener:
callbacks.addScript #selectedNodesPreDelete" print (callbacks.notificationParam())" id:#MXSHelp

Callback Event Names and notificationParam Return Values:

Below are all supported Callback Event Names and the callbacks.notificationParam() values typically returned. Depending on how the broadcast is generated, a value of 'undefined' may be returned by this method instead of the value shown.

ActionItem Notifications:

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#actionItemExecutionEnded: array

Sent when an action item finished executing.

Calling callbacks.notificationParam() returns an array with two elements:

The name of the action item.
The ID of the action item.

#actionItemExecutionStarted: array

Sent when an action item starts executing.

Calling callbacks.notificationParam() returns an array with two elements:

The name of the action item.
The ID of the action item.

#actionItemHotKeyPostExecute: array

Sent after an action item is executed via a keyboard shortcut (hotkey).

Calling callbacks.notificationParam() returns an array with two elements:

The name of the action item.
The ID of the action item.

#actionItemHotkeyPreExecute: array

Sent before an action item is executed via a keyboard shortcut (hotkey).

Calling callbacks.notificationParam() returns an array with two elements:

The name of the action item.
The ID of the action item.

Animation Notifications:

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#animateOff: undefined

Sent when the Animate button is turned off.

#animateOn: undefined

Sent when the Animate button is turned on.

#animationRangeChange: undefined

Sent when the Animation range is changed.

#animLayersDisabled: array of nodes

Sent just after animation layers are disabled on some nodes in the scene.

Calling callbacks.notificationParam() within the callback function returns the array of nodes.

#animLayersEnabled: array of nodes

Sent just after animation layers are enabled on some nodes in the scene.

Calling callbacks.notificationParam() within the callback function returns the array of nodes.

Render Dialog and Renderer Plugin Notifications:

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#tabbedDialogCreated: #(integer, integer)

Sent after the tabbed render dialog has been created.

#tabbedDialogDeleted: #(integer, integer)

Sent after the tabbed render dialog has been deleted.

#renderParamsChanged: undefined

Sent whenever the common renderer parameters have changed.

#preRendererChange: undefined

Sent before the current renderer is changed, or the type of one of the renderers is changed.

#postRendererChange: undefined

Sent after the current renderer is changed, or the type of one of the renderers is changed.

Image Viewer Display Notifications:

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#imageViewerUpdate: IVFB Interface

Sent by an image viewer (or the rendered frame window) to request that its custom rollouts update their UI. Calling callbacks.notificationParam() returns an IVFB interface which allows rollouts to be added to the Virtual Frame Buffer (a.k.a. Rendered Frame Window).

#preImageViewerDisplay: IVFB Interface

Sent after the image viewer is created, but before it becomes visible. Calling callbacks.notificationParam() returns an IVFB interface which allows rollouts to be added to the Virtual Frame Buffer (a.k.a. Rendered Frame Window).

Available in 3ds Max 2009 and higher.

#postImageViewerDisplay: IVFB Interface

Sent after the image viewer becomes visible. Calling callbacks.notificationParam() returns an IVFB interface which allows rollouts to be added to the Virtual Frame Buffer (a.k.a. Rendered Frame Window).

Available in3ds Max 2009 and higher.

Rendering Notifications:

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#preRender: Array

Sent before rendering is started. This notification is sent out before the renderer creates the render instance objects, which means that you can create nodes and other objects as a response to this event. When rendering multiple frames, this event is sent only once at the beginning of the rendering phase, and not on a per-frame basis. In the #preRender callback, you can't change any of the render parameters (height, width, aliasing, etc) and affect the current render sessions. Those parameters have already been set up internally in 3ds Max, and so changes to them won't occur until the next render session occurs.

Returns a 28 element array - see the SDK help file, class RendParams, for more information on the parameter definitions.

1 - Name - rpar -> rendType

2 - Boolean - rpar -> isNetRender

3 - Boolean - rpar -> fieldRender

4 - Integer - rpar -> fieldOrder

5 - Time - rpar -> frameDur

6 - Boolean - rpar -> colorCheck

7 - Integer - rpar -> vidCorrectMethod

8 - Integer - rpar -> ntscPAL

9 - Boolean - rpar -> superBlack

10 - Integer - rpar -> sbThresh

11 - Boolean - rpar -> rendHidden

12 - Boolean - rpar -> force2Side

13 - Boolean - rpar -> inMtlEdit

14 - Float - rpar -> mtlEditTile

15 - Boolean - rpar -> mtlEditAA

16 - Boolean - rpar -> multiThread

17 - Boolean - rpar -> useEnvironAlpha

18 - Boolean - rpar -> dontAntialiasBG

19 - Boolean - rpar -> useDisplacement

20 - Boolean - rpar -> useRadiosity

21 - Boolean - rpar -> computeRadiosity

22 - TextureMap - rpar -> envMap

23 - Time - rpar -> firstFrame

24 - Integer - rpar -> scanBandHeight

25 - Integer - rpar -> extraFlags

26 - Point2 - rpar -> width, rpar -> height

27 - Boolean - rpar -> filterBG

28 - Boolean - rpar -> alphaOutOnAdditive

#postRender: undefined

Sent after rendering has finished. This notification is sent out after the renderer destroys the render instance objects, which means that you can create nodes and other objects as a response to this event. When rendering multiple frames, this event is sent only once at the end of the rendering phase, and not on a per-frame basis.

#preRenderEval: time

Sent just before the renderer starts evaluating objects.

Returns the time being rendered

#preRenderFrame: Array

Sent just before each frame is rendered by the renderer. This notification is sent out after the renderer has taken a snapshot of the scene geometry. At the time of this call the scene cannot be modified. The renderer has already called GetRenderMesh() on all the object instances, and the materials and lights are already updated. If you don't modify anything that is rendered, then it is okay to use this callback. The current frame being rendered is set into the MAXScript currentTime context and system global, so any references to other scene object properties will automatically be resolved at the currently rendering frame's time. This notification is not sent out when the renderer is called to update the Material Editor sample spheres, only during output rendering.

#postRenderFrame: Array

Sent just after each frame is rendered by the renderer. The current frame being rendered is set into the MAXScript currentTime context and system global, so any references to other scene object properties will automatically be resolved at the currently rendering frame's time. This notification is not sent out when the renderer is called to update the Material Editor sample spheres, only during output rendering.

Returns a 22 element array - see the SDK help file, class RenderGlobalContext, for more information on the parameter definitions.

1 - Integer - rendParams -> projType

2 - Point2 - rendParams -> devWidth, rendParams -> devHeight

3 - Point2 - rendParams -> xscale, rendParams -> yscale

4 - Point2 - rendParams -> xc, rendParams- > yc

5 - Boolean - rendParams -> antialias

6 - Matrix3 - rendParams -> camToWorld

7 - Matrix3 - rendParams -> worldToCam

8 - Point2 - rendParams -> nearRange, rendParams -> farRange

9 - Float - rendParams -> devAspect

10 - Float - rendParams -> frameDur

11 - TextureMap - rendParams -> envMap

12 - Color - rendParams -> globalLightLevel

13 - Time - rendParams -> time

14 - Boolean - rendParams -> wireMode

15 - Float - rendParams -> wire_thick

16 - Boolean - rendParams -> force2Side

17 - Boolean - rendParams -> inMtlEdit

18 - Boolean - rendParams -> fieldRender

19 - Boolean - rendParams -> first_field

20 - Boolean - rendParams -> field_order

21 - Boolean - rendParams -> objMotBlur

22 - Integer - rendParams -> nBlurFrames

#beginRenderingReflectRefractMap: undefined

Sent before preparing Reflect and Refract Maps for rendering

#beginRenderingActualFrame: undefined

Sent after render setup and immediately before the actual render begins

#beginRenderingTonemappingImage: undefined

Sent before rendering Tonemapping image

WARNING:

You cannot change an object's mesh in a #preRenderFrame , #postRenderFrame or any of the #beginRendering* callbacks, particularly if the mesh isn't animated. The renderer has already evaluated the original mesh and holds a pointer to that mesh. Changing the object's mesh will delete the old mesh, but the renderer doesn't know this, and when trying to render the now deleted mesh will crash.

EXAMPLE:

For an example of using the #preRender and #postRender callbacks, see

How To ... Change Objects At Render Time

FileLink Notifications:

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#fileLinkPreAttach: undefined

Sent just before a file link attach.

#fileLinkPostAttach: undefined

Sent just after a file link attach.

#fileLinkPreBind: undefined

Sent just before a file link bind.

#fileLinkPostBind: undefined

Sent just after a file link bind.

#fileLinkPreDetatch: undefined

Sent just before a file link detach.

#fileLinkPostDetatch: undefined

Sent just after a file link detach.

#fileLinkPreReload: undefined

Sent just before a file link reload.

#fileLinkPostReload: undefined

Sent just after a file link reload.

#filelinkPostReloadPrePrune: undefined

Sent after all of the new objects for a reload have been created, but before any objects have been deleted.

File Notifications:

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#filePreOpen:(integer | undefined)

Sent before a new file is opened.

Calling callbacks.notificationParam() returns an integer value of 2 if a render preset file is being opened, undefined otherwise.

#filePostOpen: (integer |undefined)

Sent after a new file is opened successfully.

Calling callbacks.notificationParam() returns an integer value of 2 if a render preset file is being opened, undefined otherwise.

#filePreOpenProcess: #(integer, string)

Sent before the file open process starts.

Calling callbacks.notificationParam() returns an array with two elements:

Element 1 is

1 if doing a normal file load,

2 if doing an Edit>Fetch

Element 2 is the scene file name being loaded.

EXAMPLE:

callbacks.removeScripts id:#testCallback
callbacks.addScript #filePreOpenProcess "print (callbacks.notificationParam())" id:#testCallback

PERFORM A FETCH - THE CALLBACK WILL PRINT:

2
"C:\Documents and Settings\user\My Documents\3dsmax\autoback\maxhold.mx"

#fileOpenFailed: integer

Sent after a file open fails.

Calling callbacks.notificationParam() returns an integer indicating the file type, where 0 is a 3ds Max file, and 1 is a material library.

#filePostOpenProcess: undefined

Sent after the file open process has finished.

#filePreSave: string

Sent before a file is saved.

Calling callbacks.notificationParam() returns a String containing the file name.

#filePostSave: string

Sent after a file is saved.

Calling callbacks.notificationParam() returns a String containing the file name.

#filePreSaveProcess: #(integer, string)

Sent before the save process has started.

Calling callbacks.notificationParam() returns a 2 element array:

Element 1 is

1 if doing a normal file save,

2 if doing an Edit>Hold

3 if doing an Autobackup

Element 2 is the scene file name being saved.

EXAMPLE:

Evaluate the following code:

callbacks.removeScripts id:#testCallback
callbacks.addScript #filePreSaveProcess "print (callbacks.notificationParam())" id:#testCallback

Save the file to "TestingCallback.max" - the callback will print:

1
"C:\Documents and Settings\user\My Documents\3dsmax\scenes\testingcallback.max"

Perform an Edit>Fetch at this point - the callback will print:

2
"C:\Documents and Settings\user\My Documents\3dsmax\autoback\maxhold.mx"

Wait fro the Autobackup to kick in - the callback will print:

3
"C:\Documents and Settings\user\My Documents\3dsmax\autoback\AutoBackup01.max"

#filePostSaveProcess: #(integer, string)

Sent after the save process has finished.

Calling callbacks.notificationParam() returns the same 2-element array as #filePreSaveProcess - please see above for details.

#filePreSaveOld: undefined

Sent before an old version file is saved.

#filePostSaveOld: undefined

Sent after an old version file is saved.

#filePreMerge: integer

Sent before a file is merged.

Calling callbacks.notificationParam() returns an integer value of 1 if object or scene Xref merged, undefined otherwise.

#filePostMerge: integer

Sent after a file is merged successfully.

Calling callbacks.notificationParam() returns an integer value of 1 if object or scene Xref merged, undefined otherwise.

#filePostMerge2: #(integer, integer)

Sent after a file is merged successfully, right after #filePostMerge.

Calling callbacks.notificationParam() returns an array with two elements, with the first element being the file save version, and the second element the file save as version.

For example, if loading a file saved from 3ds Max 2017, where a Save As Type was set to 3ds Max 2016, the values would be 19000 (MAX_RELEASE_R19) and 18000 (MAX_RELEASE_R189).

#filePostMergeProcess: undefined

Sent after the merge process has finished.

#preImport: undefined

Sent before a file is imported.

#postImport: filename

Sent after a file is imported successfully.

Calling callbacks.notificationParam() returns the name of the file being imported. Available in in 3ds Max 2017 and higher.

#importFailed: undefined

Sent if import fails.

#preExport: undefined

Sent before a file is exported.

#postExport: filename

Sent after a file is exported successfully.

Calling callbacks.notificationParam() returns the name of the file being exported. Available in in 3ds Max 2017 and higher.

#exportFailed: undefined

Sent if export fails.

Xrefs Notifications:

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#objectXrefPreMerge: undefined

Loading XRef (typically surrounding Merge notices)

#objectXrefPostMerge: undefined

Loading XRef (typically surrounding Merge notices)

#sceneXrefPreMerge: undefined

Loading XRef (typically surrounding Merge notices)

#sceneXrefPostMerge: undefined

Loading XRef (typically surrounding Merge notices)

Layer System Notifications:

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#layerCreated: BaseLayer (reftarg)

Sent after layer created.

Calling callbacks.notificationParam() returns a layer ReferenceTarget.

NOTE:There is a known problem with #layerCreated - a layer may be created if an object is merged or an object XRef is performed, but these actions do not broadcast a #layerCreated event.

#layerDeleted: BaseLayer (reftarg)

Sent before layer deleted, callbacks.notificationParam() returns the layer.

#layerParentChanged: #(BaseLayer, BaseLayer)

Sent after the parent of a layer was changed.

Calling callbacks.notificationParam() returns an array containing two elements, the new parent and the old parent.

#nodeLayerChanged: #(node, BaseLayer, BaseLayer)

Sent after node placed on new layer, callbacks.notificationParam() returns an array containing 3 elements - the node, the old layer and the new layer

Manipulate Mode Notifications:

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#manipulateModeOn: undefined

Sent when entering manipulate mode.

#manipulateModeOff: undefined

Sent when exiting manipulate mode.

Modifier Panel Notifications:

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#modPanelObjPreChange: undefined

Sent just before the current edit object is about to change in Modify panel.

#modPanelObjPostChange: undefined

Sent just after the current edit object changes in Modify panel.

#modPanelSelChanged: undefined

Sent whenever the Modify panel opens on a new selection, either because the Modify panel was just selected or because a new selection is made in the scene. The notify occurs at a point just prior to panel redraw but after the selection has been established, so that callback functions can modify the panel state without it being overwritten.

#ModPanelSubObjectLevelChanged: #(newSOlevelIndex, oldSOlevelIndex)

Sent whenever the Modify panel changes the sub-object level. Calling callbacks.notificationParam() returns an array containing the new SO level number and the old SO level number. Available in 3ds Max 9 and higher.

Modifier Notifications:

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#preModifierAdded: #(node, modifier)

Sent before a modifier is added to a node.

Calling callbacks.notificationParam() within the callback function will return a 2 element array containing the node and the modifier which was added.

#postModifierAdded: #(node, modifier)

Sent after a modifier is added to a node.

Calling callbacks.notificationParam() within the callback function will return a 2 element array containing the node and the modifier which was added.

#preModifierDeleted: #(node, modifier)

Sent before a modifier is deleted from a node.

Calling callbacks.notificationParam() within the callback function will return a 2 element array containing the node and the modifier which was deleted.

#postModifierDeleted: #(node, modifier)

Sent after a modifier is deleted from a node.

Calling callbacks.notificationParam() within the callback function will return a 2 element array containing the node and the modifier which was deleted.

Material Library Notifications:

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#mtlLibPreOpen: undefined

Sent just before loading a material library.

#mtlLibPostOpen: materiallib

Sent just after loading a material library.

Calling callbacks.notificationParam() within the callback function will return the MaterialLibrary loaded.

#mtlLibPreSave: undefined

Sent just before saving a material library.

#mtlLibPostSave: undefined

Sent just after saving a material library.

#mtlLibPreMerge: undefined

Sent just before merging a material library.

#mtlLibPostMerge: undefined

Sent just after merging a material library.

Material Notifications:

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#FailedDirectXMaterialTextureLoad: undefined

Sent when a bitmap fails to load in the DirectX Shader Material.

This is usually when DirectX does not support the file format. The developer can register for this notification so that they can convert the format into a DirectX texture resource.

#mtlRefAdded: material

Called when a material reference is added.

Calling callbacks.notificationParam() within the callback function returns the Material.

#mtlRefDeleted: material

Called when a material reference is deleted.

Calling callbacks.notificationParam() within the callback function returns the Material

#proxyTempDisableStart: undefined

#proxyTempDisableEnd: undefined

Sent before and after an operation that temporarily disables bitmap proxies.

Calling callbacks.notificationParam() within the callback function returns undefined