#include <mxsPlugin.h>

Inheritance diagram for MSSimpleObjectXtnd:

Public Member Functions
	MSSimpleObjectXtnd (MSPluginClass *pc, BOOL loading)
	~MSSimpleObjectXtnd ()
void	DeleteThis ()
ReferenceTarget *	get_delegate ()
void	GetClassName (MSTR &s)
	Retrieves the name of the plugin class.
Class_ID	ClassID ()
	Retrieves a constant that uniquely identifies the plugin class.
void	FreeCaches ()
int	NumSubs ()
Animatable *	SubAnim (int i)
MSTR	SubAnimName (int i)
int	NumParamBlocks ()
IParamBlock2 *	GetParamBlock (int i)
IParamBlock2 *	GetParamBlockByID (BlockID id)
void *	GetInterface (ULONG id)
	Inherited from Animatable.
int	NumRefs ()
	Returns the total number of references this ReferenceMaker can hold.
RefTargetHandle	GetReference (int i)
	Returns the 'i-th' reference.
RefTargetHandle	Clone (RemapDir &remap)
	This method is used by 3ds Max to clone an object.
MCHAR *	GetObjectName ()
void	BeginEditParams (IObjParam ip, ULONG flags, Animatable prev)
void	EndEditParams (IObjParam ip, ULONG flags, Animatable next)
int	HitTest (TimeValue t, INode inode, int type, int crossing, int flags, IPoint2 p, ViewExp *vpt)
	This method is called to determine if the specified screen point intersects the item.
int	Display (TimeValue t, INode inode, ViewExp vpt, int flags)
	This is called by the system to have the item display itself (perform a quick render in viewport, using the current TM).
void	GetWorldBoundBox (TimeValue t, INode inode, ViewExp vpt, Box3 &box)
	This method returns the world space bounding box for Objects (see below for the Sub-object gizmo or Modifiers gizmo version).
void	GetLocalBoundBox (TimeValue t, INode inode, ViewExp vpt, Box3 &box)
	This is the object space bounding box, the box in the object's local coordinates.
void	Snap (TimeValue t, INode inode, SnapInfo snap, IPoint2 p, ViewExp vpt)
	Checks the point passed for a snap and updates the SnapInfo structure.
CreateMouseCallBack *	GetCreateMouseCallBack ()
	This method allows the system to retrieve a callback object used in creating an object in the 3D viewports.
BOOL	HasUVW ()
	It is called to find out if the object is has UVW coordinates.
void	SetGenUVW (BOOL sw)
	This method is called to change the state of its Generate UVW boolean.
ObjectState	Eval (TimeValue time)
	This method is called to evaluate the object and return the result as an ObjectState.
void	InitNodeName (MSTR &s)
	This is the default name of the node when it is created.
Interval	ObjectValidity (TimeValue t)
	This method returns the validity interval of the object as a whole at the specified time.
int	CanConvertToType (Class_ID obtype)
	Indicates whether the object can be converted to the specified type.
Object *	ConvertToType (TimeValue t, Class_ID obtype)
	This method converts this object to the type specified and returns a pointer it.
void	GetCollapseTypes (Tab< Class_ID > &clist, Tab< MSTR * > &nlist)
	When the user clicks on the Edit Stack button in the modify branch a list of 'Convert To:' types is presented.
void	GetDeformBBox (TimeValue t, Box3 &box, Matrix3 *tm, BOOL useSel)
	This method computes the bounding box in the objects local coordinates or the optional space defined by tm.
int	IntersectRay (TimeValue t, Ray &r, float &at, Point3 &norm)
	This method is called to compute the intersection point and surface normal at this intersection point of the ray passed and the object.
void	BuildMesh (TimeValue t)
BOOL	OKtoDisplay (TimeValue t)
void	InvalidateUI ()
ParamDimension *	GetParameterDim (int pbIndex)
MSTR	GetParameterName (int pbIndex)
Public Attributes
SimpleObject *	delegate
Protected Member Functions
virtual void	SetReference (int i, RefTargetHandle rtarg)
	Stores a ReferenceTarget as its 'i-th' reference`.

Constructor & Destructor Documentation

MSSimpleObjectXtnd	(	MSPluginClass *	pc,
		BOOL	loading
	)

~MSSimpleObjectXtnd ( ) [inline]

{ DeleteAllRefsFromMe(); }

Member Function Documentation

void DeleteThis ( )

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Reimplemented from MSPluginSimpleObject.

ReferenceTarget* get_delegate ( ) [inline, virtual]

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Reimplemented from MSPluginSimpleObject.

{ return delegate; }

void GetClassName ( MSTR & s ) [inline, virtual]

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Retrieves the name of the plugin class.

This name is usually used internally for debugging purposes. For Material plug-ins this method is used to put up the material "type" name in the Material Editor.

Parameters:

s	Reference to a string filled in with the name of the plugin class

Reimplemented from MSPluginSimpleObject.

{ s = MSTR(pc->class_name->to_string()); }

Class_ID ClassID ( ) [inline, virtual]

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Retrieves a constant that uniquely identifies the plugin class.

This method must return the unique ID for the plugin class. If two ClassIDs conflict, the system will only load the first conflicting one it finds. A program (gencid.exe) is provided to generate unique class id values.

Returns:: A class id that uniquely identifies a plugin class

See also:: Class ClassID, List of Class IDs.

Reimplemented from MSPluginSimpleObject.

{ return pc->class_id; }

void FreeCaches ( ) [inline, virtual]

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Remarks:: This is called to delete any item that can be rebuilt. For example, the procedural sphere object has a mesh that it caches. It could call Mesh::FreeAll() on the mesh from this method. This will free the vertex/face/uv arrays. If the sphere is ever evaluated again it can just rebuild the mesh. If an object (like a sphere) has modifiers applied to it, and those modifiers are not animated, then the result of the pipeline is cached in the node. So there is no reason for the sphere to also have a cache of its representation. Therefore when this method is called, the sphere can free the data of the mesh.

Default Implementation:: {}

Reimplemented from SimpleObject.

{ delegate->FreeCaches(); }

int NumSubs ( ) [inline, virtual]

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Remarks:: The system uses a virtual array mechanism to access the sub-anims of a plug-in. This method returns the total number of sub-anims maintained by the plug-in. If a plug-in is using a parameter block to manage its parameters it should just return 1 for all the parameters directed by the parameter block.

Returns:: The number of sub-anims used by the plug-in.

Default Implementation:: { return 0; }

Reimplemented from MSPluginSimpleObject.

{ return pblocks.Count() + 1; }

Animatable* SubAnim ( int i ) [inline, virtual]

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Remarks:: This method returns a pointer to the 'i-th' sub-anim. If a plug-in is using a parameter block to manage all its parameters it should just return a pointer to the parameter block itself from this method. This method may return NULL so developers need to check the return value before calling other sub anim methods (such as SubAnimName()).

Parameters:

i	This is the index of the sub-anim to return.

Default Implementation:: { return NULL };

Reimplemented from MSPluginSimpleObject.

{ if (i == 0) return delegate; else return pblocks[i-1]; }

MSTR SubAnimName ( int i ) [inline, virtual]

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Remarks:: This method returns the name of the 'i-th' sub-anim to appear in track view. The system has no idea what name to assign to the sub-anim (it only knows it by the virtual array index), so this method is called to retrieve the name to display. Developer need to make sure the 'i-th' SubAnim() is non-NULL or this method will fail.

Parameters:

i	The index of the parameter name to return

Returns:: The name of the 'i-th' parameter.

Reimplemented from MSPluginSimpleObject.

{ if (i == 0) return delegate->GetObjectName(); else return pblocks[i-1]->GetLocalName(); }

int NumParamBlocks ( ) [inline, virtual]

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Remarks:: This method is available in release 3.0 and later only.

This method returns the number of ParamBlock2s in this instance.

Default Implementation:: { return 0; }

Reimplemented from MSPluginSimpleObject.

{ return pblocks.Count(); }

IParamBlock2* GetParamBlock ( int i ) [inline, virtual]

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Remarks:: This method return 'i-th' ParamBlock2 in this instance (or NULL if not available).

Parameters:

i	The zero based index of the ParamBlock2 to return.

Default Implementation:: { return NULL; }

Reimplemented from MSPluginSimpleObject.

{ return pblocks[i]; }

IParamBlock2* GetParamBlockByID ( BlockID id ) [inline]

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Reimplemented from MSPluginSimpleObject.

{ return MSPlugin::GetParamBlockByID(id); }

void* GetInterface ( ULONG id ) [inline, virtual]

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Inherited from Animatable.

Returns a pointer to the interface.

Parameters:

id	- The id of the interface.

Returns:: A Pointer to the Interface

Reimplemented from MSPluginSimpleObject.

{ if (id == I_MAXSCRIPTPLUGIN) return (MSPlugin*)this; else return MSPluginSimpleObject::GetInterface(id); }

int NumRefs ( ) [virtual]

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Returns the total number of references this ReferenceMaker can hold.

The plugin implements this method to indicate the total number of of references it can make. This includes all references whether they are NULL (inactive) or non-NULL (active) at the time when this method is called. A plugin can hold a variable number of references, thus the return value of this method is not to be cached and reused by client code.

Returns:: The total number of references this plugin can hold. The default implementation is return 0.

Reimplemented from MSPluginSimpleObject.

RefTargetHandle GetReference ( int i ) [virtual]

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Returns the 'i-th' reference.

The plugin implements this method to return its 'i-th' reference. The plug-in simply keeps track of its references using an integer index for each one. This method is normally called by the system.

Parameters:

i	- The index of the reference to retrieve. Valid values are from 0 to NumRefs()-1.

Returns:: The reference handle of the 'i-th' reference. Note that different calls to this method with the same 'i' value can result in different reference handles being retrieved, as the plugin changes the scene objects it references as its 'i-th' reference.

Reimplemented from MSPluginSimpleObject.

virtual void SetReference	(	int	i,
		RefTargetHandle	rtarg
	)		`[protected, virtual]`

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Stores a ReferenceTarget as its 'i-th' reference`.

The plugin implements this method to store the reference handle passed to it as its 'i-th' reference. In its implementation of this method, the plugin should simply assign the reference handle passed in as a parameter to the member variable that holds the 'i-th' reference. Other reference handling methods such as ReferenceMaker::DeleteReference(), or ReferenceMaker::ReplaceReference() should not be called from within this method. The plugin itself or other plugins should not call this method directly. The system will call this method when a new reference is created or an existing one is replaced by calling ReferenceMaker::ReplaceReference().

Parameters:

i	- The index of the reference to store. Valid values are from 0 to NumRefs()-1.
rtarg	- The reference handle to store.

Reimplemented from MSPluginSimpleObject.

RefTargetHandle Clone ( RemapDir & remap ) [virtual]

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This method is used by 3ds Max to clone an object.

See also:

CloneRefHierarchy(), class RemapDir This method is called by 3ds Max to have the plugin clone itself. The plug-in's implementation of this method should copy both the data structure and all the data residing in the data structure of this reference target. The plugin should clone all its references as well. Also, the plug-in's implementation of this method must call BaseClone(). In order for classes derived from this class to clone cleanly, the Clone method should just create the new instance, and then call an implementation of BaseClone that clones the references and copies any other necessary data. For example:

            class MyDerivedPlugin
                : public MyBasePlugin
            {
                const int MY_REFERENCE = 1;

                ReferenceTarget* Clone(RemapDir& remap)
                {
                    ReferenceTarget* result = new MyDerivedPlugin();
                    BaseClone(this, result, remap);
                    return result;
                }

                void BaseClone(ReferenceTarget* from, ReferenceTarget* to, RemapDir& remap)
                {
                    if (!to || !from || from == to)
                        return;    
                    MyBasePlugin::BaseClone(from, to, remap);
                    to->ReplaceReference(MY_REFERENCE, remap->CloneRef(from->GetReference(MY_REFERENCE)));
                }
            };

This method should not be directly called by plug-ins. Instead, either RemapDir::CloneRef() or CloneRefHierachy() should be used to perform cloning. These methods ensure that the mapping from the original object to the clone is added to the RemapDir used for cloning, which may be used during backpatch operations

Note:: See the remarks in method BaseClone() below.

Parameters:

remap - A RemapDir instance used for remapping references during a Clone.

Returns:: A pointer to the cloned item.

Reimplemented from MSPluginSimpleObject.

MCHAR* GetObjectName ( ) [inline, virtual]

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Returns:: the name that will appear in the history browser (modifier stack).

Reimplemented from MSPluginSimpleObject.

{ return pc->class_name->to_string(); }

void BeginEditParams	(	IObjParam *	ip,
		ULONG	flags,
		Animatable *	prev
	)		`[virtual]`

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Remarks:: This method is called by the system when the user may edit the item's (object, modifier, controller, etc.) parameters.

Parameters:

ip	Interface pointer. The developer can use it to call methods such as AddRollupPage(). Note that this pointer is only valid between BeginEditParams() and EndEditParams(). It should not be used outside this interval.
flags	Describe which branch of the command panel or dialog the item is being edited in. The following are possible values: BEGIN_EDIT_CREATE Indicates an item is being edited in the create branch. BEGIN_EDIT_MOTION Indicates a controller is being edited in the motion branch. BEGIN_EDIT_HIERARCHY Indicates a controller is being edited in the Pivot subtask of the hierarchy branch. BEGIN_EDIT_IK Indicates a controller is being edited in the IK subtask of the hierarchy branch. BEGIN_EDIT_LINKINFO Indicates a controller is being edited in the Link Info subtask of the hierarchy branch.
prev	Pointer to an Animatable object. This parameter may be used in the motion and hierarchy branches of the command panel. This pointer allows a plug-in to look at the ClassID of the previous item that was being edited, and if it is the same as this item, to not replace the entire UI in the command panel, but simply update the values displayed in the UI fields. This prevents the UI from 'flickering' when the current item begins its edit. For example, if you are in the motion branch and are looking at an item's PRS controller values, and then select another item that is displayed with a PRS controller, the UI will not change - only the values displayed in the fields will change. If however you selected a target camera that has a lookat controller (not a PRS controller) the UI will change because a different set of parameters need to be displayed. Note that for items that are edited in the modifier branch this field can be ignored.

Reimplemented from MSPluginSimpleObject.

void EndEditParams	(	IObjParam *	ip,
		ULONG	flags,
		Animatable *	next
	)		`[virtual]`

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Remarks:: This method is called when the user is finished editing an objects parameters. The system passes a flag into the EndEditParams() method to indicate if the rollup page should be removed. If this flag is TRUE, the plug-in must un-register the rollup page, and delete it from the panel.

Parameters:

ip	An interface pointer. The developer may use the interface pointer to call methods such as DeleteRollupPage().
flags	The following flag may be set: END_EDIT_REMOVEUI If TRUE, the item's user interface should be removed.
next	Animatable pointer. Can be used in the motion and hierarchy branches of the command panel. It allows a plug-in to look at the ClassID of the next item that was being edited, and if it is the same as this item, to not replace the entire UI in the command panel. Note that for items that are edited in the modifier branch this field can be ignored.

Reimplemented from MSPluginSimpleObject.

int HitTest	(	TimeValue	t,
		INode *	inode,
		int	type,
		int	crossing,
		int	flags,
		IPoint2 *	p,
		ViewExp *	vpt
	)		`[inline, virtual]`

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This method is called to determine if the specified screen point intersects the item.

The method returns nonzero if the item was hit; otherwise 0.

Parameters:

t	The time to perform the hit test.
inode	A pointer to the node to test.
type	The type of hit testing to perform. See Scene and Node Hit Test Types. for details.
crossing	The state of the crossing setting. If TRUE crossing selection is on.
flags	The hit test flags. See Scene and Node Hit Testing Flags for details.
p	The screen point to test.
vpt	An interface pointer that may be used to call methods associated with the viewports.

Returns:: Nonzero if the item was hit; otherwise 0.

Reimplemented from SimpleObject.

                        { return delegate->HitTest(t, inode, type, crossing, flags, p, vpt); }

int Display	(	TimeValue	t,
		INode *	inode,
		ViewExp *	vpt,
		int	flags
	)		`[inline, virtual]`

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This is called by the system to have the item display itself (perform a quick render in viewport, using the current TM).

Note: For this method to be called the object's validity interval must be invalid at the specified time t. If the interval is valid, the system may not call this method since it thinks the display is already valid.

Parameters:

t	The time to display the object.
inode	The node to display.
vpt	An interface pointer that may be used to call methods associated with the viewports.
flags	See Display Flags.

Returns:: The return value is not currently used.

Reimplemented from SimpleObject.

                        { return delegate->Display(t, inode, vpt, flags); }

void GetWorldBoundBox	(	TimeValue	t,
		INode *	inode,
		ViewExp *	vp,
		Box3 &	box
	)		`[inline, virtual]`

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This method returns the world space bounding box for Objects (see below for the Sub-object gizmo or Modifiers gizmo version).

The bounding box returned by this method does not need to be precise. It should however be calculated rapidly. The object can handle this by transforming the 8 points of its local bounding box into world space and take the minimums and maximums of the result. Although this isn't necessarily the tightest bounding box of the objects points in world space, it is close enough.

Parameters:

t	The time to compute the bounding box.
inode	The node to calculate the bounding box for.
vp	An interface pointer that can be used to call methods associated with the viewports.
box	Contains the returned bounding box.

Reimplemented from SimpleObject.

{ delegate->GetWorldBoundBox(t, inode, vpt, box); }

void GetLocalBoundBox	(	TimeValue	t,
		INode *	inode,
		ViewExp *	vp,
		Box3 &	box
	)		`[inline, virtual]`

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This is the object space bounding box, the box in the object's local coordinates.

The system expects that requesting the object space bounding box will be fast.

Parameters:

t	The time to retrieve the bounding box.
inode	The node to calculate the bounding box for.
vp	An interface pointer that may be used to call methods associated with the viewports.
box	Contains the returned bounding box.

Reimplemented from SimpleObject.

{ delegate->GetLocalBoundBox(t, inode, vpt,  box ); }

void Snap	(	TimeValue	t,
		INode *	inode,
		SnapInfo *	snap,
		IPoint2 *	p,
		ViewExp *	vpt
	)		`[inline, virtual]`

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Checks the point passed for a snap and updates the SnapInfo structure.

Note:: Developers wanting to find snap points on an Editable Mesh object should see the method XmeshSnap::Snap() in /MAXSDK/SAMPLES/SNAPS/XMESH/XMESH.CPP.

Parameters:

t	The time to check.
inode	The node to check.
snap	The snap info structure to update.
p	The screen point to check.
vpt	An interface pointer that may be used to call methods associated with the viewports.

Reimplemented from SimpleObject.

{ delegate->Snap(t, inode, snap, p, vpt); }

CreateMouseCallBack* GetCreateMouseCallBack ( ) [inline, virtual]

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This method allows the system to retrieve a callback object used in creating an object in the 3D viewports.

This method returns a pointer to an instance of a class derived from CreateMouseCallBack. This class has a method proc() which is where the programmer defines the user/mouse interaction during the object creation phase.

Returns:: A pointer to an instance of a class derived from CreateMouseCallBack.

Reimplemented from MSPluginSimpleObject.

{ return delegate->GetCreateMouseCallBack(); }

BOOL HasUVW ( ) [inline, virtual]

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It is called to find out if the object is has UVW coordinates.

This method returns TRUE if the object has UVW coordinates; otherwise FALSE. In 3ds Max 2.0 and later there is code in the renderer that will automatically turn on the UVW coordinates of the base object if UV's are missing (and needed). The base object has to implement two simple methods to make this work: HasUVW() and SetGenUVW(). Developers are encouraged to put these methods in their objects: it makes using the program easier for the user. If they are not implemented, it doesn't cause any real harm: it will just operate as before and put up the missing UVW's message. Here is how the procedural sphere implements these methods:

    BOOL SphereObject::GetGenUVW()
    {
        BOOL genUVs;
        Interval v;
        pblock->GetValue(PB_GENUVS, 0, genUVs, v);
        return genUVs;
    }
    
    void SphereObject::SetGenUVW(BOOL sw)
    {
        if (sw==GetGenUVW()) return;
        pblock->SetValue(PB_GENUVS,0, sw);
    }

Important Note: The pblock->SetValue() will cause a call to NotifyDependents(FOREVER, PART_TEXMAP, REFMSG_CHANGE), which will invalidate the UVW cache. It is essential that this call be made, so if the 'generate UVW' boolean is not handled by a parameter block, then NotifyDependents() needs to be called explicitly. Also Note: For "modifiable objects" that pass up the pipeline getting modified, such as TriObject, EditTriObject, etc., which cannot generate their own UVWs, but can carry them in their data structures, only this HasUVW() method needs to be implemented. For example, here is the implementation for TriObject: BOOL TriObject::HasUVW() { return mesh.tvFace?1:0; }

Reimplemented from MSPluginSimpleObject.

{ return delegate->HasUVW(); }

void SetGenUVW ( BOOL sw ) [inline, virtual]

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This method is called to change the state of its Generate UVW boolean.

If the state changes, the object must send a REFMSG_CHANGE up the pipeline by calling NotifyDependents(). This applies to map channel 1.

Parameters:

sw	The new state for the generate UVW flag.

Reimplemented from MSPluginSimpleObject.

{ delegate->SetGenUVW(sw); }

ObjectState Eval ( TimeValue t ) [virtual]

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This method is called to evaluate the object and return the result as an ObjectState.

When the system has a pointer to an object it doesn't know if it's a procedural object or a derived object. So it calls Eval() on it and gets back an ObjectState. A derived object managed by the system may have to call Eval() on its input for example. A plug-in (like a procedural object) typically just returns itself. A plug-in that does not just return itself is the Morph Object (/MAXSDK/SAMPLES/OBJECTS/MORPHOBJ.CPP). This object uses a morph controller to compute a new object and fill in an ObjectState which it returns.

Parameters:

t	Specifies the time to evaluate the object.

Returns:: The result of evaluating the object as an ObjectState.

Sample Code:

Typically this method is implemented as follows:

    { return ObjectState(this); }

Reimplemented from SimpleObject.

void InitNodeName ( MSTR & s ) [inline, virtual]

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This is the default name of the node when it is created.

Parameters:

s	The default name of the node is stored here.

Reimplemented from SimpleObject.

{s = GetObjectName();}

Interval ObjectValidity ( TimeValue t ) [virtual]

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This method returns the validity interval of the object as a whole at the specified time.

Parameters:

t	The time to compute the validity interval.

Default Implementation:: { return FOREVER; }

Returns:: The validity interval of the object.

Reimplemented from SimpleObject.

int CanConvertToType ( Class_ID obtype ) [inline, virtual]

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Indicates whether the object can be converted to the specified type.

If the object returns nonzero to indicate it can be converted to the specified type, it must handle converting to and returning an object of that type from ConvertToType().

See also:: Class ObjectConverter for additional details on converting objects between types.

Parameters:

obtype The Class_ID of the type of object to convert to. See Class Class_ID, List of Class_IDs.

Returns:: Nonzero if the object can be converted to the specified type; otherwise 0.

Default Implementation:: { return 0; }

Reimplemented from SimpleObject.

{ return delegate->CanConvertToType(obtype); }

Object* ConvertToType	(	TimeValue	t,
		Class_ID	obtype
	)		`[inline, virtual]`

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This method converts this object to the type specified and returns a pointer it.

Note that if ConvertToType() returns a new object it should be a completely different object with no ties (pointers or references) to the original.

See also:: class ObjectConverter for additional details on converting objects between types.

The following is an issue that developers of world space modifiers need to: be aware of if the world space modifier specifies anything but generic deformable objects as its input type. In other words, if a world space modifier, in its implementation of Modifier::InputType(), doesn't specifically return defObjectClassID then the following issue regarding the 3ds Max pipeline needs to be considered. Developers of other plug-ins that don't meet this condition don't need to be concerned with this issue.

World space modifiers that work on anything other than generic deformable: objects are responsible for transforming the points of the object they modify into world space using the ObjectState TM. To understand why this is necessary, consider how 3ds Max applies the node transformation to the object flowing down the pipeline.

In the geometry pipeline architecture, the node in the scene has its: transformation applied to the object in the pipeline at the transition between the last object space modifier and the first world space modifier. The node transformation is what places the object in the scene -- thus this is what puts the object in world space. The system does this by transforming the points of the object in the pipeline by the node transformation. This is only possible however for deformable objects. Deformable objects are those that support the Object::IsDeformable(), NumPoints(), GetPoint() and SetPoint() methods. These deformable objects can be deformed by the system using these methods, and thus the system can modify the points to put them in world space itself.

If a world space modifier does not specify that it works on deformable

objects, the system is unable to transform the points of the object into world space. What it does instead is apply the transformation to the ObjectState TM. In this case, a world space modifier is responsible for transforming the points of the object into world space itself, and then setting the ObjectState TM to the identity. There is an example of this in the sample code for the Bomb space warp. The Bomb operates on TriObjects and implements InputType() as { return Class_ID(TRIOBJ_CLASS_ID,0); }. Since it doesn't specifically return defObjectClassID, it is thus responsible for transforming the points of the object into world space itself. It does this in its implementation of ModifyObject() as follows:

    if (os->GetTM())
    {
        Matrix3 tm = *(os->GetTM());
        for (int i=0; i<triOb->mesh.getNumVerts(); i++) {
            triOb->mesh.verts[i] = triOb->mesh.verts[i] *tm;
        }
        os->obj->UpdateValidity(GEOM_CHAN_NUM,os->tmValid());
        os->SetTM(NULL,FOREVER);
    }

As the code above shows, the Bomb checks if the ObjectState TM is non-NULL. If it is, the points of the object are still not in world space and thus must be transformed. It does this by looping through the points of the TriObject and multiplying each point by the ObjectState TM. When it is done, it sets the ObjectState TM to NULL to indicate the points are now in world space. This ensure that any later WSMs will not transform the points with this matrix again.

For the Bomb world space modifier this is not a problem since it specifies: in its implementation of ChannelsChanged() that it will operate on the geometry channel (PART_GEOM). Certain world space modifiers may not normally specify PART_GEOM in their implementation of ChannelsChanged(). Consider the camera mapping world space modifier. Its function is to apply mapping coordinates to the object it is applied to. Thus it would normally only specify PART_TEXMAP for ChannelsChanged(). However, since it operates directly on TriObjects, just like the Bomb, the system cannot transform the points into world space, and therefore the camera mapping modifier must do so in its implementation of ModifyObject(). But since it is actually altering the points of the object by putting them into world space it is altering the geometry channel. Therefore, it should really specify PART_GEOM | PART_TEXMAP in its implementation of ChannelsChanged(). If it didn't do this, but went ahead and modified the points of the object anyway, it would be transforming not copies of the points, but the original points stored back in an earlier cache or even the base object.

This is the issue developers need to be aware of. To state this in simple: terms then: Any world space modifier that needs to put the points of the object into world space (since it doesn't implement InputType() as defObjectClassID) needs to specify PART_GEOM in its implementation of ChannelsChanged().

Parameters:

t	The time at which to convert.
obtype	The Class_ID of the type of object to convert to. See Class Class_ID, List of Class_IDs.

Returns:: A pointer to an object of type obtype.

Default Implementation:: { return NULL; }

Sample Code:

The following code shows how a TriObject can be retrieved from a node. Note on the code that if you call ConvertToType() on an object and it returns a pointer other than itself, you are responsible for deleting that object.

    // Retrieve the TriObject from the node
    int deleteIt;
    TriObject *triObject = GetTriObjectFromNode(ip->GetSelNode(0),deleteIt);
    // Use the TriObject if available
    if (!triObject) return;
    // ...
    // Delete it when done...
    if (deleteIt) triObject->DeleteMe();
    
    // Return a pointer to a TriObject given an INode or return NULL
    // if the node cannot be converted to a TriObject
    TriObject *Utility::GetTriObjectFromNode(INode *node, int &deleteIt)
    {
        deleteIt = FALSE;
        Object *obj = node->EvalWorldState(0).obj;
        if (obj->CanConvertToType(Class_ID(TRIOBJ_CLASS_ID, 0))) {
            TriObject *tri = (TriObject *) obj->ConvertToType(0,Class_ID(TRIOBJ_CLASS_ID, 0));
    // Note that the TriObject should only be deleted
    // if the pointer to it is not equal to the object
    // pointer that called ConvertToType()
            if (obj != tri) 
                deleteIt = TRUE;
            return tri;
        }
        else {
            return NULL;
        }
    }

Reimplemented from SimpleObject.

                                                                {
                        // CAL-10/1/2002: Don't return the delegate, because it might be deleted.
                        //      Return a copy of the delegate instead. (422964)
                        Object* obj = delegate->ConvertToType(t, obtype);
                        if (obj == delegate) obj = delegate->MakeShallowCopy(OBJ_CHANNELS);
                        return obj;
                    }

void GetCollapseTypes	(	Tab< Class_ID > &	clist,
		Tab< MSTR * > &	nlist
	)		`[inline, virtual]`

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When the user clicks on the Edit Stack button in the modify branch a list of 'Convert To:' types is presented.

The use may click on one of these choices to collapse the object into one of these types (for instance, an Editable Mesh or an Editable NURBS object). This method returns a list of Class_IDs and descriptive strings that specify the allowable types of objects that this object may be collapsed into. Note: Most plug-ins call the base class method in Object in their implementation of this method. The base class implementation provided by Object checks if the object can convert to both an editable mesh and an editable spline. If it can, these are added to the allowable types.

Parameters:

clist	The table of allowable Class_IDs.
nlist	The table of pointers to strings that correspond to the table of Class_IDs above.

Sample Code:

    void SphereObject::GetCollapseTypes(Tab<Class_ID> &clist,Tab<MSTR*>&nlist)
    {
        Object::GetCollapseTypes(clist, nlist);
        Class_ID id = EDITABLE_SURF_CLASS_ID;
        MSTR *name = new MSTR(GetString(IDS_SM_NURBS_SURFACE));
        clist.Append(1,&id);
        nlist.Append(1,&name);
    }

Reimplemented from Object.

{ delegate->GetCollapseTypes(clist, nlist); }

void GetDeformBBox	(	TimeValue	t,
		Box3 &	box,
		Matrix3 *	tm,
		BOOL	useSel
	)		`[inline, virtual]`

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This method computes the bounding box in the objects local coordinates or the optional space defined by tm.

Note: If you are looking for a precise bounding box, use this method and pass in the node's object TM (INode::GetObjectTM()) as the matrix.

Parameters:

t	The time to compute the box.
box	A reference to a box the result is stored in.
tm	This is an alternate coordinate system used to compute the box. If the tm is not NULL this matrix should be used in the computation of the result.
useSel	If TRUE, the bounding box of selected sub-elements should be computed; otherwise the entire object should be used.

Reimplemented from SimpleObject.

{ delegate->GetDeformBBox(t, box, tm, useSel); }

int IntersectRay	(	TimeValue	t,
		Ray &	r,
		float &	at,
		Point3 &	norm
	)		`[inline, virtual]`

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This method is called to compute the intersection point and surface normal at this intersection point of the ray passed and the object.

Parameters:

t	The time to compute the intersection.
r	Ray to intersect. See Class Ray.
at	The point of intersection.
norm	Surface normal at the point of intersection.

Returns:: Nonzero if a point of intersection was found; otherwise 0.

See also:: The Mesh class implementation of this method.

Reimplemented from SimpleObject.

{ return delegate->IntersectRay(t, r, at, norm); }

void BuildMesh ( TimeValue t ) [inline, virtual]

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Remarks:: This method is called to build the mesh representation of the object using its parameter settings at the time passed. The plug-in should use the data member mesh to store the built mesh.

Parameters:: TimeValue t

The time at which to build the mesh.

Reimplemented from MSPluginSimpleObject.

{ delegate->BuildMesh(t); }

BOOL OKtoDisplay ( TimeValue t ) [inline, virtual]

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Remarks:: This method returns a BOOL to indicate if it is okay to draw the object at the time passed. Normally it is always OK to draw the object, so the default implementation returns TRUE. However for certain objects it might be a degenerate case to draw the object at a certain time (perhaps the size went to zero for example), so these objects could return FALSE.

Parameters:: TimeValue t

The time at which the object would be displayed.

Default Implementation:: { return TRUE; }

Returns:: TRUE if the object may be displayed; otherwise FALSE.

Reimplemented from MSPluginSimpleObject.

{ return delegate->OKtoDisplay(t); }

void InvalidateUI ( ) [inline, virtual]

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Remarks:: This is called if the user interface parameters needs to be updated because the user moved to a new time. The UI controls must display values for the current time.

Example:

If the plug-in uses a parameter map for handling its UI, it may call a method of the parameter map to handle this:

        pmapParam->Invalidate();

If the plug-in does not use parameter maps, it should call the SetValue() method on each of its controls that display a value, for example the spinner controls. This will cause to the control to update the value displayed. The code below shows how this may be done for a spinner control. Note that ip and pblock are assumed to be initialized interface and parameter block pointers:

        void foo(IObjParam* ip, IParamBlock* pblock)
        {
            float newval;
            Interval valid = FOREVER;
            TimeValue t = ip->GetTime();
            // Get the value from the parameter block at the current time.
            pblock->GetValue( PB_ANGLE, t, newval, valid );
            // Set the value. Note that the notify argument is passed as FALSE.
            // This ensures no messages are sent when the value changes.
            angleSpin->SetValue( newval, FALSE );
        }

Reimplemented from MSPluginSimpleObject.

{ delegate->InvalidateUI(); }

ParamDimension* GetParameterDim ( int pbIndex ) [inline, virtual]

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Remarks:: This method returns the parameter dimension of the parameter whose index is passed.

Parameters:: int pbIndex

The index of the parameter to return the dimension of.

Returns:: Pointer to a ParamDimension.

Example:: return stdNormalizedDim;

Default Implementation:: The default implementation returns defaultDim.

See also:: ParamDimension

Reimplemented from SimpleObject.

{ return delegate->GetParameterDim(pbIndex); }

MSTR GetParameterName ( int pbIndex ) [inline, virtual]

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Remarks:: This method returns the name of the parameter whose index is passed.

Parameters:: int pbIndex

The index of the parameter to return the name of.

Returns:: The name of the parameter.

Default Implementation:: The default implementation returns MSTR(_M("Parameter"))

Reimplemented from SimpleObject.

{ return delegate->GetParameterName(pbIndex); }

Member Data Documentation

SimpleObject* delegate

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MSSimpleObjectXtnd Class Reference

Public Member Functions

Public Attributes

Protected Member Functions

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation