SoLDMGlobalResourceParameters Class Reference
[Misc]

Global resource parameters for LDM. More...

#include <LDM/SoLDMGlobalResourceParameters.h>

Public Types
enum	VisualFeedbackParam { DRAW_TILES, DRAW_SLICES_TEX, DRAW_TOPOLOGY, DRAW_TILE_OUTLINE, SHOW_TILES_VALUATED, SHOW_LOAD_UNLOAD_TILES, USE_FAKE_DATA }
Static Public Member Functions
static void	setMaxMainMemory (int maxMainMemory)
static int	getMaxMainMemory ()
static void	setMaxTexMemory (int maxTexMemory)
static int	getMaxTexMemory ()
static void	setTex3LoadRate (int loadRate)
static int	getTex3LoadRate ()
static void	setTex2LoadRate (int loadRate)
static int	getTex2LoadRate ()
static void	setNumIO (unsigned int numIO)
static unsigned int	getNumIO ()
static void	setVisualFeedbackParam (VisualFeedbackParam param, SbBool state)
static SbBool	getVisualFeedbackParam (VisualFeedbackParam param)
static void	setViewCulling (SbBool state, SbBool forceRedraw=TRUE)
static SbBool	getViewCulling ()
static void	setScreenResolutionCulling (SbBool flag)
static SbBool	getScreenResolutionCulling ()
static void	setIgnoreFullyTransparentTiles (SbBool state)
static SbBool	getIgnoreFullyTransparentTiles ()
static void	setViewpointRefinement (SbBool state)
static SbBool	getViewpointRefinement ()
static void	setSliceEqualResolution (SbBool state, SbBool forceRedraw=TRUE)
static SbBool	getSliceEqualResolution ()
static void	setLoadNotificationRate (int)
static int	getLoadNotificationRate ()
static void	setLoadCB (SoLDMLoadCB func, void userData=NULL)
static void	setMonitoringCB (SoLDMMonitoringCB func, int memAmount, void userData=NULL)
static int64_t	getDefaultMaxTexMem ()
static int64_t	getDefaultMaxMainMem ()
static void	setMax2DTexMemory (uint64_t maxMemory)
static uint64_t	getMax2DTexMemory ()
Deprecated

enum	TileCacheType { NONE, FULLRES_ONLY, ALL, LOWRES_ONLY = FULLRES_ONLY }
static SoDEPRECATED void	setMaxNumTriangles (int maxNumTriangles)
static SoDEPRECATED int	getMaxNumTriangles ()
static SoDEPRECATED void	setTileCacheType (TileCacheType cacheType)
static SoDEPRECATED TileCacheType	getTileCacheType ()
static SoDEPRECATED void	setMax2DTextures (int numTextures)
static SoDEPRECATED int	getMax2DTextures ()
static SoDEPRECATED int64_t	getDefaultMaxTex2D ()
static SoDEPRECATED void	setMoveLowResolution (SbBool state)
static SoDEPRECATED SbBool	getMoveLowResolution ()

Detailed Description

Global resource parameters for LDM.

This class contains functions for controlling global resource parameters for the LDM module.

For extensions that use the LDM module, particularly VolumeViz, these parameters can have a significant effect on resource usage (primarily memory) and rendering performance.

Memory management

This class allows the application to specify how much CPU and GPU memory VolumeViz can use to load data and textures. By default the main memory and texture memory limits are set to a percentage of the total available system and GPU memory (see the setMaxMainMemory() and setMaxTexMemory() methods). Applications can use the SoCpuDevice and SoGLDevice classes to query the total and available memory on the CPU and GPU. There is an additional memory allocation for the BufferObject cache described below. How VolumeViz uses CPU memory depends on the data source (tiled or not tiled), the tile cache policy (see setTileCacheType() method) and the SoPreferences variable LDM_USE_IN_MEM_COMPRESSION.

Tiles:
VolumeViz uses a data manager called LDM to manage volume data. LDM manages volume data in chunks called "tiles". If the volume size is larger than the tile size, then there are two classes of tile: full-resolution tiles containing actual data values and low-resolution tiles containing sub-sampled data values. The application may have native data that is already tiled or the data may be pre-processed to create tiles and store them in the LDM file format. In an LDM format file the tiles may optionally be compressed to save disk space and memory, but in this case, the tiles must be expanded before sending to the GPU. If the data is not tiled, for example disk formats like DICOM and SEGY or an in-memory volume, then tiles must be created in memory at runtime.

Tile size:
Note that the default tile size is small and generally you wll get better performance with non-tiled data by explicitly setting a larger tile size (see the ldmResourceParameters field and SoLDMResourceParameters::tileDimension). If the volume size is 512^3 or less then the tile size may be set to the volume size to avoid the overhead of tiling. Do not set the tile size larger than 512 for a volume data set. However, if the volume is actually a large "image", i.e. the Z dimension is 1, then setting the tile size to 1024 may improve performance.

Caches:
LDM allocates CPU memory for the CPU Tile Cache and the secondary BufferObject cache. The CPU tile cache is normally as large as needed or other memory requirements allow. If the volume is larger than the available or allowed CPU memory, then LDM keeps the "most important" tiles in memory (importance is determined by various heuristics set in this class and in SoLDMResourceParameters). The BufferObject cache is normally small and is used to temporarily store tiles that are created by LDM at run-time.

CPU Tile Cache (main memory)
VolumeViz uses this amount of CPU memory as the primary cache for LDM data tiles. The main memory limit is set in megabytes using the setMaxMainMemory() method. If the data set is small enough to fit in system memory, then generally the memory limit should be set high enough to allow this. If the data set is larger than system memory, then the memory limit should be set as high as possible without impacting the application's other needs for memory. If the tile size is (for example) 64 and each voxel is a float value, then each tile requires approximately 1 MB of system memory. However since Open Inventor 8.5, the system memory requirement is reduced for compressed LDM tiles (stored compressed) and for uniform tiles (stored as a single value).

When there are multiple LDM data sets, by default each data set receives getMaxMainMemory() divided by the number of datasets. Each time a new data set is created the per-dataset value is recomputed and some memory is taken away from existing data sets. Note: This default allocation of memory to multiple data sets is not optimal if the data sets have significantly different sizes. For example the memory required for a height field is normally much less than for a volume. In this case the application can explicitly allocate memory to each data set using the maxMainMemory field of the SoLDMResourceParameters object associated with the data set (see the SoDataSet::ldmResourceParameters field).

GPU Tile Cache (texture memory)
VolumeViz uses this amount of GPU memory to cache LDM data tiles on the GPU. The texture memory limit is set in megabytes using the setMaxTexMemory() method. This value can also be set separately for each data set using SoLDMResourceParameters.

Warning:: Some systems combine GPU memory and CPU memory. If 4GB are allocated on CPU and 4GB on GPU, the system may see a total amount of 8GB of private memory used by the process, which can lead to out of memory errors or swapping issues. When dealing with such issues, it is best to ensure that the total amount of memory allocated on both CPU and GPU by the program is lower than the available CPU memory.

BufferObject cache
In some cases LDM needs to create tiles on-the-fly at runtime. To reduce memory usage and avoid duplicating application data, these created tiles are considered temporary and are stored in the BufferObject cache. This is a secondary cache that is separate from, and in addition to, the CPU tile cache (main memory). How the BufferObject cache is used depends on the data source (tiled or not) and the tile caching policy (see setTileCacheType()).

For example when compressed tiles are loaded from an LDM format file, they are stored in the CPU tile cache still compressed (to reduce the memory requirement). When the tile data is needed to send data to the GPU, a temporary uncompressed tile is created and stored in the BufferObject cache. The BufferObject cache is also used to expand uniform tiles, which are stored in the LDM file and in memory as a single value.

For non-tiled data (e.g. SEGY or DICOM or in-memory volume), depending on the tile cache policy, tiles are created from the source data when needed to send data to the GPU and temporarily stored in the BufferObject cache.

The BufferObject cache size can only be set using the SoPreferences variable OIV_BUFFER_OBJECT_CACHE_SIZE. The size is set in number of tiles (not amount of memory) so the actual size of this cache depends on both the tile size and the data type size, i.e. it is larger for floating point data than for byte data. The default size is 50 tiles. The BufferObject cache size can only be set globally, not for each data set. The BufferObject cache was added in Open Inventor version 8.5.

Member Enumeration Documentation

enum SoLDMGlobalResourceParameters::TileCacheType

Tile cache management policy.

See the Memory Management section above for more information including the definitions of CPU Tile Cache and BufferObject cache. Used with setTileCacheType() method.

For tiled data that is not compressed (e.g. a standard LDM format file), the TileCacheType setting has no effect and only the CPU tile cache is used.

Setting the SoPreferences variable LDM_USE_IN_MEM_COMPRESSION to false (zero) effectively sets the tile cache type to mode 'ALL'.

Deprecated:: Deprecated since Open Inventor 9630
Moved to SoLDMResourceParameters in OIV 10.

Enumerator:

NONE	For non-tiled data like DICOM or SEGY or an in-memory volume, no tiles are are stored in the CPU tile cache. All tiles are created when needed (e.g. to send data to the GPU), calling the volume reader (SoVolumeReader) and all tiles (both low resolution and full resolution) are stored temporarily in the BufferObject cache. The CPU tile cache is not used. If the entire volume fits in GPU memory, then tiles will only be created once, otherwise performance will be reduced because some time is required when tiles need to be re-created and are not in the BufferObject cache. For compressed tiled data (e.g. an LDM format file created with compression), the compressed tiles are stored in the CPU tile cache "as is" to reduce the memory requirement. Uncompressed tiles are created from the compressed data when needed (to send data to the GPU) and are stored temporarily in the BufferObject cache. This mode saves memory but can reduce interactivity.
FULLRES_ONLY	This option really means "low res only" (the name is fixed is OIV 10). For non-tiled data like DICOM or SEGY or an in-memory volume, tiles are created when needed (to send data to the GPU), but low resolution tiles are stored in the CPU tile cache and full resolution tiles are stored in the BufferObject cache. For compressed tiled data (e.g. an LDM format file created with compression), low resolution tiles are uncompressed when loaded and stored uncompressed in the CPU tile cache. Full resolution tiles are stored compressed in the CPU tile cache (to reduce the CPU memory requirement). Uncompressed full resolution tiles are created from the compressed data when needed (to send data to the GPU) and are stored in the BufferObject cache. This setting uses more memory than 'NONE' but saves time when low resolution tiles need to be sent to the GPU. It uses less memory than 'ALL'.
ALL	For non-tiled data like DICOM or SEGY or an in-memory volume, tiles are created when needed (to send data to the GPU) and all tiles (both low resolution and full resolution) are stored in the CPU tile cache. This mode is recommended for non-tiled volumes loaded from disk when the volume will fit in memory (generally true for medical volumes). NOTE: For an in-memory volume, this setting will duplicate the data in memory. For an in-memory volume it's better to use the LOWRES_ONLY or NONE setting. For tiled data that is compressed (e.g. an LDM format file created with compression), all tiles are uncompressed when loaded and stored uncompressed in the CPU tile cache. This setting uses the most memory, but saves time when tiles need to be sent to the GPU. The BufferObject cache is not used.
LOWRES_ONLY	FULLRES_ONLY was renamed to LOWRES_ONLY in OIV10, this is here to help transition. Added at the end for better compatibility

enum SoLDMGlobalResourceParameters::VisualFeedbackParam

Visual feedback modes.

Used with setVisualFeedbackParam() method.

Enumerator:

DRAW_TILES	Draw the tiles of SoVolumeRender or SoVolumeSkin primitives. They are drawn by default.
DRAW_SLICES_TEX	Use texturing for SoOrthoSlice, SoObliqueSlice, and SoVolumeGeometry primitives. They are used by default.
DRAW_TOPOLOGY	Show tiles loaded in main memory. This implies showing the multiresolution topology. The tile outlines of tiles of full resolution are drawn with a brighter yellow. The topology is not drawn by default.
DRAW_TILE_OUTLINE	Draw tile outlines for all primitives. The tile outline of tiles of full resolution are drawn with a brighter gray for the volume, and a brighter green for the slices. Outlines are not drawn by default.
SHOW_TILES_VALUATED	Show tiles visited by the Tile Visitor. They are not shown by default. For the default LDM implementation, displays an octree representation showing traversal of the octree. Red dots are tiles that have been valuated. Blue indicates the minimum and maximum resolution thresholds. Yellow shows the octree itself.
SHOW_LOAD_UNLOAD_TILES	Show tiles loaded (in red) and unloaded (in blue) in texture memory. They are not shown by default.
USE_FAKE_DATA	Use fake data instead of the real data during loading into main memory. The fake data is programmatically generated and is designed to illustrate features of Large Data Management. Fake data is not used by default.

Member Function Documentation

static int64_t SoLDMGlobalResourceParameters::getDefaultMaxMainMem ( ) [inline, static]

Returns the default maximum system (CPU) memory in MB.

static SoDEPRECATED int64_t SoLDMGlobalResourceParameters::getDefaultMaxTex2D ( ) [static]

Returns the default maximum number of 2D textures.

Deprecated:: Deprecated since Open Inventor 9500
No longer used. Will be removed in OIV10.

static int64_t SoLDMGlobalResourceParameters::getDefaultMaxTexMem ( ) [inline, static]

Returns the default maximum GPU memory in MB.

static SbBool SoLDMGlobalResourceParameters::getIgnoreFullyTransparentTiles ( ) [static]

Returns the IgnoreFullyTransparentTiles flag.

See setIgnoreFullyTransparentTiles().

static int SoLDMGlobalResourceParameters::getLoadNotificationRate ( ) [static]

Returns the load notification rate.

See setLoadNotificationRate().

static uint64_t SoLDMGlobalResourceParameters::getMax2DTexMemory ( ) [static]

Get the maximum number of 2D textures allowed to be loaded.

See setMax2DTexMemory.

static SoDEPRECATED int SoLDMGlobalResourceParameters::getMax2DTextures ( ) [static]

Get the maximum number of 2D textures allowed to be loaded.

Deprecated. Use getMax2DTexMemory instead. See setMax2DTextures.

Deprecated:: Deprecated since Open Inventor 9500
No longer used. Will be removed in OIV10.

static int SoLDMGlobalResourceParameters::getMaxMainMemory ( ) [static]

Returns the maximum main memory in MB for all the VolumeViz data sets.

See setMaxMainMemory.

static SoDEPRECATED int SoLDMGlobalResourceParameters::getMaxNumTriangles ( ) [static]

Get the maximum number of triangles allowed to be rendered for all VolumeViz render nodes.

See setMaxNumTriangles.

Deprecated:: Deprecated since Open Inventor 9700
maxNumTriangles is no longer used by SoHeightFieldRender. Number of triangles is controlled by the node SoComplexity.

static int SoLDMGlobalResourceParameters::getMaxTexMemory ( ) [static]

Returns the maximum texture memory in MB for all the VolumeViz data sets.

See setMaxTexMemory.

static SoDEPRECATED SbBool SoLDMGlobalResourceParameters::getMoveLowResolution ( ) [static]

Returns the move low resolution flag.

See setMoveLowResolution().

Deprecated:: Deprecated since Open Inventor 9610
No longer used. Use SoLDMResourceParameters' LoadPolicy field instead.

static unsigned int SoLDMGlobalResourceParameters::getNumIO ( ) [static]

Returns the current number of loading threads.

See setNumIO().

static SbBool SoLDMGlobalResourceParameters::getScreenResolutionCulling ( ) [static]

Returns the screen resolution culling state.

See setScreenResolutionCulling().

static SbBool SoLDMGlobalResourceParameters::getSliceEqualResolution ( ) [static]

Returns the slice equal resolution flag.

See setSliceEqualResolution().

static int SoLDMGlobalResourceParameters::getTex2LoadRate ( ) [static]

Returns the maximum number of 2D textures allowed to be loaded into texture memory per frame for all the VolumeViz data sets.

See setTex2LoadRate().

static int SoLDMGlobalResourceParameters::getTex3LoadRate ( ) [static]

Returns the maximum number of tiles (3D textures) allowed to be downloaded into texture (GPU) memory per frame for all the VolumeViz data sets.

See setTex3LoadRate().

static SoDEPRECATED TileCacheType SoLDMGlobalResourceParameters::getTileCacheType ( ) [static]

Returns the LDM tile cache setting.

See setTileCacheType().

Deprecated:: Deprecated since Open Inventor 9630
Moved to SoLDMResourceParameters in OIV 10.

static SbBool SoLDMGlobalResourceParameters::getViewCulling ( ) [static]

Returns the view culling flag.

See setViewCulling().

static SbBool SoLDMGlobalResourceParameters::getViewpointRefinement ( ) [static]

Returns the viewpoint refinement flag.

See setViewpointRefinement().

static SbBool SoLDMGlobalResourceParameters::getVisualFeedbackParam ( VisualFeedbackParam param ) [static]

Returns the state of the specified visual feedback parameter.

static void SoLDMGlobalResourceParameters::setIgnoreFullyTransparentTiles ( SbBool state ) [static]

Sets the IgnoreFullyTransparentTiles flag.

Default is FALSE. When TRUE, tiles for which all voxels between their min and max values are fully transparent (alpha = 0) will not be refined. In other words a low resolution version will always be used. This can reduce memory requirements for volumes with significant "empty space".

static void SoLDMGlobalResourceParameters::setLoadCB	(	SoLDMLoadCB *	func,
		void *	userData = `NULL`
	)			`[static]`

Sets a callback to be called with the tile loading state.

The callback function is called with true when the process starts loading tiles. And with false when loading is complete, in other words when LDM has the best possible set of tiles in memory for the current render nodes, viewpoint, etc.

NOTE: This feature is available with VolumeVizLDM only.

static void SoLDMGlobalResourceParameters::setLoadNotificationRate ( int ) [static]

Sets the load notification rate (number of tiles).

When rate new tiles have been loaded in main memory, a redraw will be scheduled. This is useful because tiles are loaded asynchronously using multiple threads. The default is 50 tiles. Which means, for example, if each voxel is one byte and the tileSize is 64x64x64, a redraw will be scheduled whenever 13 MB of data has been loaded.

static void SoLDMGlobalResourceParameters::setMax2DTexMemory ( uint64_t maxMemory ) [static]

Sets the maximum 2D texture GPU memory in MB allowed to be loaded for all VolumeViz data sets.

The sum of 2D texture memory allowed per data set (see SoLDMResourceParameters::max2DTextures field) must be less than or equal to this value. The total amount of GPU memory allowed is set using the setMaxTexMemory method. This method limits the amount of GPU memory that can be used by (for example) SoOrthoSlice and SoVolumeSkin nodes. This can be useful when combining slices and volume rendering because the 3D textures used by volume rendering require much more GPU memory. Default is 5% of GPU memory available at application startup.

static SoDEPRECATED void SoLDMGlobalResourceParameters::setMax2DTextures ( int numTextures ) [static]

Sets the maximum number of 2D textures allowed to be loaded for all VolumeViz data sets.

The sum of each number of 2D textures allowed per data set (see SoLDMResourceParameters::max2DTextures field) must be less than or equal to this value. The total amount of GPU memory allowed is set using the setMaxTexMemory method. This method limits the amount of GPU memory that can be used by (for example) SoOrthoSlice and SoVolumeSkin nodes. This can be useful when combining slices and volume rendering because the 3D textures used by volume rendering require much more GPU memory. Default (since Open Inventor 8.1) is 5% of total GPU memory Deprecated. Use setMax2DTexMemory instead.

Deprecated:: Deprecated since Open Inventor 9500
No longer used. Will be removed in OIV10.

static void SoLDMGlobalResourceParameters::setMaxMainMemory ( int maxMainMemory ) [static]

Sets the maximum main (CPU) memory, in MB, to use for all VolumeViz data sets.

You can also set the maximum main memory for each data set separately using the maxMainMemory field of the data set's SoLDMResourceParameters object (see SoDataSet::ldmResourceParameters). The sum of all per data set values must be less than or equal to the value set here.

Default (since Open Inventor 8.1) is 50% of total CPU memory up to 70% of free memory. See SoCpuDevice to query available CPU memory.

static SoDEPRECATED void SoLDMGlobalResourceParameters::setMaxNumTriangles ( int maxNumTriangles ) [static]

Sets the maximum number of triangles allowed to be rendered for all VolumeViz render nodes.

The default value is zero, which means there is no limit.

: Note: Starting with Open Inventor version 9.4, the default height field rendering algorithm (SoHeightFieldRender) does not use this parameter. The number of triangles rendered is controlled by the current complexity setting (SoComplexity).

The sum of the max triangles values per data set (see SoLDMResourceParameters::maxNumTriangles field) must be less or equal to this value. This is an approximate value because some nodes using this parameter draw indivisible chunks of triangles. Particularly useful for limiting the number of triangles generated by SoHeightFieldRender.

Deprecated:: Deprecated since Open Inventor 9700
maxNumTriangles is no longer used by SoHeightFieldRender. Number of triangles is controlled by the node SoComplexity.

static void SoLDMGlobalResourceParameters::setMaxTexMemory ( int maxTexMemory ) [static]

Sets the maximum texture (GPU) memory, in MB, for all VolumeViz data sets.

You can also set the maximum texture memory for each data set separately using the maxTexMemory field of the data set's SoLDMResourceParameters object (see SoDataSet::ldmResourceParameters). The sum of all per data set values must be less than or equal to the value set here.

Default is 75% of GPU memory available at application startup. See SoGLDevice to query available GPU memory.

static void SoLDMGlobalResourceParameters::setMonitoringCB	(	SoLDMMonitoringCB *	func,
		int	memAmount,
		void *	userData = `NULL`
	)			`[static]`

Sets a monitoring callback .

This provides a snapshot of the tile loading performance. The callback will be called each time memAmount MB of data have been loaded, with the amount of data and the amount of time elapsed to load that data.

NOTE: This feature is available with VolumeVizLDM only.

static SoDEPRECATED void SoLDMGlobalResourceParameters::setMoveLowResolution ( SbBool state ) [static]

Sets the low resolution when moving flag.

Default is FALSE. When TRUE, lower resolution tiles are automatically used while the camera is moving (e.g. when user is panning and rotating.

Deprecated:: Deprecated since Open Inventor 9610
No longer used. Use SoLDMResourceParameters' LoadPolicy field instead.

static void SoLDMGlobalResourceParameters::setNumIO ( unsigned int numIO ) [static]

Sets how many simultaneous tile loading threads to use if multi I/O mode is on (it is on when LDM mode is on).

The IVVR_NUM_LOADERS preference (see SoPreference) lets you choose the initial number of loading threads at launch. Changing this preference at runtime will not affect the actual number of loading threads, use this method instead. If this preference is not set, the default is 4.

The IVVR_MAX_NUM_LOADERS preference lets you set a maximum number of tile loading threads. If this method is called with a larger number, the number of loading threads will be set to the maximum instead. If this preference is not set, the maximum is 20.

static void SoLDMGlobalResourceParameters::setScreenResolutionCulling ( SbBool flag ) [static]

Sets the screen resolution culling flag.

Default is FALSE. When TRUE, only tiles for which the projection of a voxel is greater than or equal to 1 pixel on screen will be loaded. This avoids unnecessary loading of high resolution data for large volumes. However if you "zoom out" from a volume, it does not force lower resolution tiles to be used (high resolution tiles already in memory will still be used). If necessary use the SoLDMResourceParameters::fixedResolution field to force use of lower resolution tiles.

static void SoLDMGlobalResourceParameters::setSliceEqualResolution	(	SbBool	state,
		SbBool	forceRedraw = `TRUE`
	)			`[static]`

Sets the slice equal resolution flag.

Default is FALSE. When TRUE, slice primitives, e.g. SoOrthoSlice and SoObliqueSlice, are always rendered using a set of tiles at the same resolution level. This avoids potentially distracting visual effects caused by mixing tiles of different resolution on the same slice. But it means that the slice will be rendered at a lower resolution if it is not possible to load every tile needed for the higher resolution. When FALSE and viewpoint refinement is enabled, higher resolution tiles will be loaded for portions of the slice closer to the camera even if it is not possible to load every high resolution tile.

An alternative strategy is to enable the SoSlice::largeSliceSupport field. When large slice support is enabled, if all the required full resolution tiles have already been loaded, then the slice data is taken from LDM cache memory as usual. But if some required tiles are not currently in memory, the full resolution slice data will be loaded directly from the volume reader without loading the complete tiles. This reduces disk I/O and reduces the amount of system memory required to display the slice at full resolution, so larger (or more) slices can be displayed.

static void SoLDMGlobalResourceParameters::setTex2LoadRate ( int loadRate ) [static]

Sets the maximum number of 2D textures allowed to be downloaded into texture (GPU) memory per frame (render traversal) for all the VolumeViz data sets.

You can set this parameter separately for each data set using field SoLDMResourceParameter::tex2LoadRate. Default is 640 2D textures per frame.

Each tile needed to render a slice (SoOrthoSlice, SoVolumeSkin, etc) must be loaded into GPU memory as a 2D texture. Increasing the loadRate value reduces the number of frames required to reach maximum resolution. But the render traversal has to wait for the data transfer to finish, so each frame may take longer to render, increasing the total time to reach maximum resolution.

static void SoLDMGlobalResourceParameters::setTex3LoadRate ( int loadRate ) [static]

Sets the maximum number of 3D textures allowed to be downloaded into texture (GPU) memory, per frame (render traversal), for all VolumeViz data sets.

You can set this parameter separately for each data set using field SoLDMResourceParameter::tex3LoadRate. Default is 10 3D textures (effectively 3 tiles) per render traversal.

Each tile needed for volume rendering (SoVolumeRender) and volume geometry must be transfered to GPU memory as a 3D texture. So, for example, transfering 1000 tiles at the default loadRate (10) requires 100 frames. (How many seconds this takes depends on the frames per second possible, which in turn depends on many factors including the complexity of the scene graph.) Increasing the loadRate value reduces the number of frames required to reach maximum resolution. But the render traversal has to wait for the data transfer to finish, so each frame may take longer to render, increasing the total time to reach maximum resolution.

static SoDEPRECATED void SoLDMGlobalResourceParameters::setTileCacheType ( TileCacheType cacheType ) [static]

Specifies how LDM will cache tiles in memory.

Default is FULLRES_ONLY. See the TileCacheType enum description and the Memory Management section for more information.
This setting is global and affects all volume data sets.
Setting the SoPreferences variable LDM_USE_IN_MEM_COMPRESSION to false (zero) effectively sets the tile cache type to mode ALL.

Added in Open Inventor 8.5.

Deprecated:: Deprecated since Open Inventor 9630
Moved to SoLDMResourceParameters in OIV 10.

static void SoLDMGlobalResourceParameters::setViewCulling	(	SbBool	state,
		SbBool	forceRedraw = `TRUE`
	)			`[static]`

Sets the view culling flag.

Default is TRUE. When TRUE, only tiles that are inside the view frustum (i.e. visible) will be loaded and conversely tiles that are outside the view frustum may be discarded.

static void SoLDMGlobalResourceParameters::setViewpointRefinement ( SbBool state ) [static]

Sets the viewpoint refinement flag.

Default is TRUE. When TRUE, tile refinement depends on the viewpoint. In other words, tiles closer to the camera have higher priority and higher resolution data will be loaded for closer tiles first. This can be useful for large volumes that cannot be completely loaded in memory.

static void SoLDMGlobalResourceParameters::setVisualFeedbackParam	(	VisualFeedbackParam	param,
		SbBool	state
	)			`[static]`

Sets the specified visual feedback parameter to true or false.

The documentation for this class was generated from the following file:

LDM/SoLDMGlobalResourceParameters.h

SoLDMGlobalResourceParameters Class Reference [Misc]

Public Types

Static Public Member Functions

Deprecated

Detailed Description

SEE ALSO

Member Enumeration Documentation

Member Function Documentation

SoLDMGlobalResourceParameters Class Reference
[Misc]