--- name: "SoModelMatrixElement" section: "3" platform: "linux" package: "coin" version: "1:4.0.10-1" release: "Arch Linux 2026-11-01" platforms: ["linux"] url: "https://new.carta.tech/SoModelMatrixElement" --- # SoModelMatrixElement(3) The SoModelMatrixElement class is used to manage the current transformation. ## NAME SoModelMatrixElement - The **SoModelMatrixElement** class is used to manage the current transformation. ## SYNOPSIS \#include \ Inherits **SoAccumulatedElement**. Inherited by **SoBBoxModelMatrixElement**, and **SoGLModelMatrixElement**. ### Public Member Functions virtual void **init** (**SoState** \*state)\ virtual void **push** (**SoState** \*state)\ virtual SbBool **matches** (const **SoElement** \*element) const\ const **SbMatrix** & **getModelMatrix** (void) const\ Public Member Functions inherited from **SoElement** const **SoType** **getTypeId** (void) const\ int **getStackIndex** (void) const\ virtual void **pop** (**SoState** \*state, const **SoElement** \*prevTopElement)\ void **setDepth** (const int **depth**)\ int **getDepth** (void) const\ virtual void **print** (FILE \*file=stdout) const\ virtual **~SoElement** ()\ ### Static Public Member Functions static **SoType** **getClassTypeId** (void)\ static int **getClassStackIndex** (void)\ static void \* **createInstance** (void)\ static void **initClass** (void)\ static void **makeIdentity** (**SoState** \*const state, **SoNode** \*const node)\ static void **set** (**SoState** \*const state, **SoNode** \*const node, const **SbMatrix** &matrix)\ static void **setCullMatrix** (**SoState** \*state, **SoNode** \*node, const **SbMatrix** &matrix)\ static void **mult** (**SoState** \*const state, **SoNode** \*const node, const **SbMatrix** &matrix)\ static void **translateBy** (**SoState** \*const state, **SoNode** \*const node, const **SbVec3f** &translation)\ static void **rotateBy** (**SoState** \*const state, **SoNode** \*const node, const **SbRotation** &rotation)\ static void **scaleBy** (**SoState** \*const state, **SoNode** \*const node, const **SbVec3f** &scaleFactor)\ static **SbMatrix** **pushMatrix** (**SoState** \*const state)\ static void **popMatrix** (**SoState** \*const state, const **SbMatrix** &matrix)\ static const **SbMatrix** & **getCombinedCullMatrix** (**SoState** \*const state)\ static const **SbMatrix** & **get** (**SoState** \*const state)\ static const **SbMatrix** & **get** (**SoState** \*const state, SbBool &isIdentity)\ Static Public Member Functions inherited from **SoAccumulatedElement** static **SoType** **getClassTypeId** (void)\ static int **getClassStackIndex** (void)\ static void **initClass** (void)\ Static Public Member Functions inherited from **SoElement** static void **initClass** (void)\ static **SoType** **getClassTypeId** (void)\ static int **getClassStackIndex** (void)\ static void **initElements** (void)\ static int **getNumStackIndices** (void)\ static **SoType** **getIdFromStackIndex** (const int **stackIndex**)\ ### Protected Member Functions virtual **~SoModelMatrixElement** ()\ virtual void **makeEltIdentity** (void)\ virtual void **setElt** (const **SbMatrix** &matrix)\ virtual void **multElt** (const **SbMatrix** &matrix)\ virtual void **translateEltBy** (const **SbVec3f** &translation)\ virtual void **rotateEltBy** (const **SbRotation** &rotation)\ virtual void **scaleEltBy** (const **SbVec3f** &scaleFactor)\ virtual **SbMatrix** **pushMatrixElt** (void)\ virtual void **popMatrixElt** (const **SbMatrix** &matrix)\ Protected Member Functions inherited from **SoAccumulatedElement** virtual **~SoAccumulatedElement** ()\ void **clearNodeIds** (void)\ void **addNodeId** (const **SoNode** \*const node)\ void **setNodeId** (const **SoNode** \*const node)\ void **copyNodeIds** (const **SoAccumulatedElement** \*copyfrom)\ virtual **SoElement** \* **copyMatchInfo** (void) const\ virtual void **captureThis** (**SoState** \*state) const\ Protected Member Functions inherited from **SoElement** **SoElement** (void)\ void **capture** (**SoState** \*const state) const\ void **setTypeId** (const **SoType** **typeId**)\ void **setStackIndex** (const int index)\ **SoElement** \* **getNextInStack** (void) const\ **SoElement** \* **getNextFree** (void) const\ ### Protected Attributes **SbMatrix** **modelMatrix**\ **SbMatrix** **cullMatrix**\ **SbMatrix** **combinedMatrix**\ uint32\_t **flags**\ Protected Attributes inherited from **SoAccumulatedElement** **SbList**\< SbUniqueId \> **nodeIds**\ Protected Attributes inherited from **SoElement** **SoType** **typeId**\ int **stackIndex**\ int **depth**\ ### Additional Inherited Members Static Protected Member Functions inherited from **SoElement** static **SoElement** \* **getElement** (**SoState** \*const state, const int **stackIndex**)\ static const **SoElement** \* **getConstElement** (**SoState** \*const state, const int **stackIndex**)\ static int **createStackIndex** (const **SoType** id)\ Static Protected Attributes inherited from **SoElement** static int **classStackIndex**\ static **SoTypeList** \* **stackToType**\ ## Detailed Description The **SoModelMatrixElement** class is used to manage the current transformation. **SoModelMatrixElement** contains the object-to-world matrix. The world-to-camera transformation is stored in the **SoViewingMatrixElement** class. Note that one thing that can be a little confusing with the API is that **SoModelMatrixElement** does not contain the same matrix as the OpenGL GL\_MODELVIEW matrix. **See also** **SoViewingMatrixElement** ## Constructor & Destructor Documentation ### SoModelMatrixElement::~SoModelMatrixElement (void ) \[protected\], \[virtual\] Destructor. ## Member Function Documentation ### SoType SoModelMatrixElement::getClassTypeId (void ) \[static\] This static method returns the **SoType** object associated with objects of this class. ### int SoModelMatrixElement::getClassStackIndex (void ) \[static\] This static method returns the state stack index for the class. ### void \* SoModelMatrixElement::createInstance (void ) \[static\] *This API member is considered internal to the library, as it is not likely to be of interest to the application programmer.*\ Creates a new instance of the class type corresponding to the **SoType** object. ### void SoModelMatrixElement::initClass (void ) \[static\] Initialize relevant common data for all instances, like the type system. ### void SoModelMatrixElement::init (SoState \* state) \[virtual\] Initializes the element to its default value. The default value for modelMatrix is the identity matrix. Reimplemented from **SoAccumulatedElement**. Reimplemented in **SoBBoxModelMatrixElement**, and **SoGLModelMatrixElement**. ### void SoModelMatrixElement::push (SoState \* state) \[virtual\] This method is called every time a new element is required in one of the stacks. This happens when a writable element is requested, using **SoState::getElement()** or indirectly **SoElement::getElement()**, and the depth of the current element is less than the state depth. Override this method if your element needs to copy data from the previous top of stack. The **push()** method is called on the new element, and the previous element can be found using **SoElement::getNextInStack()**. Reimplemented from **SoAccumulatedElement**. Reimplemented in **SoBBoxModelMatrixElement**, and **SoGLModelMatrixElement**. ### SbBool SoModelMatrixElement::matches (const SoElement \* element) const \[virtual\] This function returns TRUE is the element matches another element (of the same class), with respect to cache validity. If the application programmer's extension element has a **matches()** function, it should also have a **copyMatchInfo()** function. Reimplemented from **SoAccumulatedElement**. ### void SoModelMatrixElement::makeIdentity (SoState \*const state, SoNode \*const node) \[static\] Sets the current model matrix to the identity matrix. ### void SoModelMatrixElement::set (SoState \*const state, SoNode \*const node, const SbMatrix & matrix) \[static\] Sets the current model matrix to *matrix*. ### void SoModelMatrixElement::setCullMatrix (SoState \* state, SoNode \* node, const SbMatrix & matrix) \[static\] Sets the current cull matrix. ### void SoModelMatrixElement::mult (SoState \*const state, SoNode \*const node, const SbMatrix & matrix) \[static\] Multiplies *matrix* into the model matrix. ### void SoModelMatrixElement::translateBy (SoState \*const state, SoNode \*const node, const SbVec3f & translation) \[static\] Appends *translation* to the model matrix. ### void SoModelMatrixElement::rotateBy (SoState \*const state, SoNode \*const node, const SbRotation & rotation) \[static\] Appends *rotation* to the model matrix. ### void SoModelMatrixElement::scaleBy (SoState \*const state, SoNode \*const node, const SbVec3f & scaleFactor) \[static\] Appends *scaleFactor* to the model matrix. ### SbMatrix SoModelMatrixElement::pushMatrix (SoState \*const state) \[static\] Used by **SoTransformSeparator** to store and restore model matrix. Don't use it for any other reason. ### void SoModelMatrixElement::popMatrix (SoState \*const state, const SbMatrix & matrix) \[static\] Used by **SoTransformSeparator** to store and restore model matrix. Don't use it for any other reason. ### const SbMatrix & SoModelMatrixElement::getCombinedCullMatrix (SoState \*const state) \[static\] Returns the combined cull and model matrix. This matrix is cached. ### const SbMatrix & SoModelMatrixElement::get (SoState \*const state) \[static\] Returns the current model matrix. ### const SbMatrix & SoModelMatrixElement::get (SoState \*const state, SbBool & isIdentity) \[static\] Returns the current model matrix. Sets *isIdentity* to TRUE if the model matrix is known to be an identity matrix. ### const SbMatrix & SoModelMatrixElement::getModelMatrix (void ) const Returns the current model matrix. ### void SoModelMatrixElement::makeEltIdentity (void ) \[protected\], \[virtual\] virtual method which is called from the static method **makeIdentity()**. Sets element model matrix to identity. Reimplemented in **SoBBoxModelMatrixElement**, and **SoGLModelMatrixElement**. ### void SoModelMatrixElement::setElt (const SbMatrix & matrix) \[protected\], \[virtual\] virtual method which is called from the static method **set()**. Sets element model matrix to *matrix*. Reimplemented in **SoBBoxModelMatrixElement**, and **SoGLModelMatrixElement**. ### void SoModelMatrixElement::multElt (const SbMatrix & matrix) \[protected\], \[virtual\] virtual method which is called from the static method **mult()**. Multiplies *matrix* into element model matrix. Reimplemented in **SoBBoxModelMatrixElement**, and **SoGLModelMatrixElement**. ### void SoModelMatrixElement::translateEltBy (const SbVec3f & translation) \[protected\], \[virtual\] virtual method which is called from the static method **translateBy()**. Appends *translation* to element model matrix. Reimplemented in **SoBBoxModelMatrixElement**, and **SoGLModelMatrixElement**. ### void SoModelMatrixElement::rotateEltBy (const SbRotation & rotation) \[protected\], \[virtual\] virtual method which is called from the static method **rotateBy()**. Appends *rotation* to element model matrix. Reimplemented in **SoBBoxModelMatrixElement**, and **SoGLModelMatrixElement**. ### void SoModelMatrixElement::scaleEltBy (const SbVec3f & scaleFactor) \[protected\], \[virtual\] virtual method which is called from the static method **scaleBy()**. Appends *scaleFactor* to element model matrix. Reimplemented in **SoBBoxModelMatrixElement**, and **SoGLModelMatrixElement**. ### SbMatrix SoModelMatrixElement::pushMatrixElt (void ) \[protected\], \[virtual\] virtual method which is called from the static method **pushMatrix()**. Returns current model matrix. Reimplemented in **SoBBoxModelMatrixElement**, and **SoGLModelMatrixElement**. ### void SoModelMatrixElement::popMatrixElt (const SbMatrix & matrix) \[protected\], \[virtual\] virtual method which is called from the static method **popMatrix()**. Restores model matrix to the matrix returned from **pushMatrix()**. Reimplemented in **SoBBoxModelMatrixElement**, and **SoGLModelMatrixElement**. ## Member Data Documentation ### SbMatrix SoModelMatrixElement::modelMatrix \[protected\] FIXME: write doc. ### SbMatrix SoModelMatrixElement::cullMatrix \[protected\] FIXME: write doc. ### SbMatrix SoModelMatrixElement::combinedMatrix \[protected\] FIXME: write doc. ### uint32\_t SoModelMatrixElement::flags \[protected\] FIXME: write doc. ## Author Generated automatically by Doxygen for Coin from the source code.