QCustom3DVolume#

The QCustom3DVolume class adds a volume rendered object to a graph. More

Synopsis#

Functions#

Signals#

Detailed Description#

A volume rendered object is a box with a 3D texture. Three slice planes are supported for the volume, one along each main axis of the volume.

Rendering volume objects is very performance intensive, especially when the volume is largely transparent, as the contents of the volume are ray-traced. The performance scales nearly linearly with the amount of pixels that the volume occupies on the screen, so showing the volume in a smaller view or limiting the zoom level of the graph are easy ways to improve performance. Similarly, the volume texture dimensions have a large impact on performance. If the frame rate is more important than pixel-perfect rendering of the volume contents, consider turning the high definition shader off by setting the useHighDefShader property to false.

Note

Volumetric objects are only supported with orthographic projection.

Note

Volumetric objects utilize 3D textures, which are not supported in OpenGL ES2 environments.

See also

addCustomItem() orthoProjection useHighDefShader

class PySide6.QtDataVisualization.QCustom3DVolume([parent=None])#

PySide6.QtDataVisualization.QCustom3DVolume(position, scaling, rotation, textureWidth, textureHeight, textureDepth, textureData, textureFormat, colorTable[, parent=None])

Parameters

Constructs a custom 3D volume with the given parent.

Constructs a custom 3D volume with the given position, scaling, rotation, textureWidth, textureHeight, textureDepth, textureData, textureFormat, colorTable, and optional parent.

PySide6.QtDataVisualization.QCustom3DVolume.alphaMultiplier()#
Return type

float

This property holds The value that the alpha value of every texel of the volume texture is multiplied with at the render time..

This property can be used to introduce uniform transparency to the volume. If preserveOpacity is true, only texels with at least some transparency to begin with are affected, and fully opaque texels are not affected. The value must not be negative. Defaults to 1.0f.

PySide6.QtDataVisualization.QCustom3DVolume.alphaMultiplierChanged(mult)#
Parameters

mult – float

PySide6.QtDataVisualization.QCustom3DVolume.colorTable()#
Return type

This property holds The array containing the colors for indexed texture formats..

If the texture format is not indexed, this array is not used and can be empty.

Defaults to 0.

See also

textureData setTextureFormat() colorTable()

PySide6.QtDataVisualization.QCustom3DVolume.colorTableChanged()#
PySide6.QtDataVisualization.QCustom3DVolume.createTextureData(images)#
Parameters

images

Return type

QList

Creates a new texture data array from an array of images and sets it as textureData for this volume object. The texture dimensions are also set according to image and array dimensions. All of the images in the array must be the same size. If the images are not all in the Format_Indexed8 format, all texture data will be converted into the Format_ARGB32 format. If the images are in the Format_Indexed8 format, the colorTable value for the entire volume will be taken from the first image.

Returns a pointer to the newly created array.

PySide6.QtDataVisualization.QCustom3DVolume.drawSliceFrames()#
Return type

bool

This property holds Whether slice frames are drawn around the volume..

If this property value is true, the frames of slices indicated by slice index properties will be drawn around the volume. If it is false, no slice frames will be drawn.

Drawing slice frames is independent of drawing slices, so you can show the full volume and still draw the slice frames around it. This is useful when using renderSlice() to display the slices outside the graph itself.

Defaults to false.

PySide6.QtDataVisualization.QCustom3DVolume.drawSliceFramesChanged(enabled)#
Parameters

enabled – bool

PySide6.QtDataVisualization.QCustom3DVolume.drawSlices()#
Return type

bool

This property holds Whether the specified slices are drawn instead of the full volume..

If this property value is true, the slices indicated by slice index properties will be drawn instead of the full volume. If it is false, the full volume will always be drawn. Defaults to false.

Note

The slices are always drawn along the item axes, so if the item is rotated, the slices are rotated as well.

PySide6.QtDataVisualization.QCustom3DVolume.drawSlicesChanged(enabled)#
Parameters

enabled – bool

PySide6.QtDataVisualization.QCustom3DVolume.preserveOpacity()#
Return type

bool

This property holds Whether the alpha multiplier is applied to all texels..

If this property value is true, alphaMultiplier is only applied to texels that already have some transparency. If it is false, the multiplier is applied to the alpha value of all texels. Defaults to true.

See also

alphaMultiplier

PySide6.QtDataVisualization.QCustom3DVolume.preserveOpacityChanged(enabled)#
Parameters

enabled – bool

PySide6.QtDataVisualization.QCustom3DVolume.renderSlice(axis, index)#
Parameters
  • axisAxis

  • index – int

Return type

PySide6.QtGui.QImage

Renders the slice specified by index along the axis specified by axis into an image. The texture format of this object is used.

Returns the rendered image of the slice, or a null image if an invalid index is specified.

PySide6.QtDataVisualization.QCustom3DVolume.setAlphaMultiplier(mult)#
Parameters

mult – float

This property holds The value that the alpha value of every texel of the volume texture is multiplied with at the render time..

This property can be used to introduce uniform transparency to the volume. If preserveOpacity is true, only texels with at least some transparency to begin with are affected, and fully opaque texels are not affected. The value must not be negative. Defaults to 1.0f.

PySide6.QtDataVisualization.QCustom3DVolume.setColorTable(colors)#
Parameters

colors

This property holds The array containing the colors for indexed texture formats..

If the texture format is not indexed, this array is not used and can be empty.

Defaults to 0.

See also

textureData setTextureFormat() colorTable()

PySide6.QtDataVisualization.QCustom3DVolume.setDrawSliceFrames(enable)#
Parameters

enable – bool

This property holds Whether slice frames are drawn around the volume..

If this property value is true, the frames of slices indicated by slice index properties will be drawn around the volume. If it is false, no slice frames will be drawn.

Drawing slice frames is independent of drawing slices, so you can show the full volume and still draw the slice frames around it. This is useful when using renderSlice() to display the slices outside the graph itself.

Defaults to false.

PySide6.QtDataVisualization.QCustom3DVolume.setDrawSlices(enable)#
Parameters

enable – bool

This property holds Whether the specified slices are drawn instead of the full volume..

If this property value is true, the slices indicated by slice index properties will be drawn instead of the full volume. If it is false, the full volume will always be drawn. Defaults to false.

Note

The slices are always drawn along the item axes, so if the item is rotated, the slices are rotated as well.

PySide6.QtDataVisualization.QCustom3DVolume.setPreserveOpacity(enable)#
Parameters

enable – bool

This property holds Whether the alpha multiplier is applied to all texels..

If this property value is true, alphaMultiplier is only applied to texels that already have some transparency. If it is false, the multiplier is applied to the alpha value of all texels. Defaults to true.

See also

alphaMultiplier

PySide6.QtDataVisualization.QCustom3DVolume.setSliceFrameColor(color)#
Parameters

colorPySide6.QtGui.QColor

This property holds The color of the slice frame..

Transparent slice frame color is not supported.

Defaults to black.

See also

drawSliceFrames

PySide6.QtDataVisualization.QCustom3DVolume.setSliceFrameGaps(values)#
Parameters

valuesPySide6.QtGui.QVector3D

This property holds The size of the air gap left between the volume itself and the frame in each dimension..

The gap can be different on different dimensions. The values are fractions of the volume thickness in the same dimension. The values cannot be negative.

Defaults to QVector3D(0.01, 0.01, 0.01).

See also

drawSliceFrames

PySide6.QtDataVisualization.QCustom3DVolume.setSliceFrameThicknesses(values)#
Parameters

valuesPySide6.QtGui.QVector3D

This property holds The thickness of the slice frames for each dimension..

The values are fractions of the volume thickness in the same dimension. The values cannot be negative.

Defaults to QVector3D(0.01, 0.01, 0.01).

See also

drawSliceFrames

PySide6.QtDataVisualization.QCustom3DVolume.setSliceFrameWidths(values)#
Parameters

valuesPySide6.QtGui.QVector3D

This property holds The width of the slice frame..

The width can be different on different dimensions, so you can for example omit drawing the frames on certain sides of the volume by setting the value for that dimension to zero. The values are fractions of the volume thickness in the same dimension. The values cannot be negative.

Defaults to QVector3D(0.01, 0.01, 0.01).

See also

drawSliceFrames

PySide6.QtDataVisualization.QCustom3DVolume.setSliceIndexX(value)#
Parameters

value – int

This property holds The x-dimension index into the texture data indicating which vertical slice to show..

Setting any dimension to negative indicates no slice or slice frame for that dimension is drawn. If all dimensions are negative, no slices or slice frames are drawn and the volume is drawn normally.

Defaults to -1.

PySide6.QtDataVisualization.QCustom3DVolume.setSliceIndexY(value)#
Parameters

value – int

This property holds The y-dimension index into the texture data indicating which horizontal slice to show..

Setting any dimension to negative indicates no slice or slice frame for that dimension is drawn. If all dimensions are negative, no slices or slice frames are drawn and the volume is drawn normally.

Defaults to -1.

PySide6.QtDataVisualization.QCustom3DVolume.setSliceIndexZ(value)#
Parameters

value – int

This property holds The z-dimension index into the texture data indicating which vertical slice to show..

Setting any dimension to negative indicates no slice or slice frame for that dimension is drawn. If all dimensions are negative, no slices or slice frames are drawn and the volume is drawn normally.

Defaults to -1.

PySide6.QtDataVisualization.QCustom3DVolume.setSliceIndices(x, y, z)#
Parameters
  • x – int

  • y – int

  • z – int

A convenience function for setting all three slice indices (x, y, and z) at once.

See also

textureData

PySide6.QtDataVisualization.QCustom3DVolume.setSubTextureData(axis, index, image)#
Parameters

Sets a single 2D subtexture of the 3D texture along the specified axis of the volume. The index parameter specifies the subtexture to set. The source image must be in the format specified by the textureFormat property if textureFormat is indexed. If textureFormat is Format_ARGB32 , the image is converted to that format. The image must have the size of the cross-section of the volume texture along the specified axis. The orientation of the image should correspond to the orientation of the slice image produced by renderSlice() method along the same axis.

Note

Each x-dimension line of the data needs to be 32-bit aligned when targeting the y-axis or z-axis. If textureFormat is Format_Indexed8 and the textureWidth value is not divisible by four, padding bytes might need to be added to each x-dimension line of the image to properly align it. The padding bytes should indicate a fully transparent color to avoid rendering artifacts. It is not guaranteed that QImage will do this automatically.

PySide6.QtDataVisualization.QCustom3DVolume.setSubTextureData(axis, index, data)
Parameters
  • axisAxis

  • index – int

  • data – str

Sets a single 2D subtexture of the 3D texture along the specified axis of the volume. The index parameter specifies the subtexture to set. The texture data must be in the format specified by the textureFormat property and have the size of the cross-section of the volume texture along the specified axis multiplied by the texture format color depth in bytes. The data is expected to be ordered similarly to the data in images produced by the renderSlice() method along the same axis.

Note

Each x-dimension line of the data needs to be 32-bit aligned when targeting the y-axis or z-axis. If textureFormat is Format_Indexed8 and the textureWidth value is not divisible by four, padding bytes might need to be added to each x-dimension line of the data to properly align it. The padding bytes should indicate a fully transparent color to avoid rendering artifacts.

PySide6.QtDataVisualization.QCustom3DVolume.setTextureData(arg__1)#
Parameters

arg__1

PySide6.QtDataVisualization.QCustom3DVolume.setTextureDepth(value)#
Parameters

value – int

This property holds The depth of the 3D texture defining the volume content in pixels..

Defaults to 0.

Note

The textureData value may need to be resized or recreated if this value is changed. Defaults to 0.

PySide6.QtDataVisualization.QCustom3DVolume.setTextureDimensions(width, height, depth)#
Parameters
  • width – int

  • height – int

  • depth – int

A convenience function for setting all three texture dimensions (width, height, and depth) at once.

See also

textureData

PySide6.QtDataVisualization.QCustom3DVolume.setTextureFormat(format)#
Parameters

formatFormat

Sets the format of the textureData property to format. Only two formats are supported currently: Format_Indexed8 and Format_ARGB32 . If an indexed format is specified, colorTable must also be set. Defaults to Format_ARGB32 .

PySide6.QtDataVisualization.QCustom3DVolume.setTextureHeight(value)#
Parameters

value – int

This property holds The height of the 3D texture defining the volume content in pixels..

Defaults to 0.

Note

The textureData value may need to be resized or recreated if this value is changed. Defaults to 0.

PySide6.QtDataVisualization.QCustom3DVolume.setTextureWidth(value)#
Parameters

value – int

This property holds The width of the 3D texture defining the volume content in pixels..

Defaults to 0.

Note

The textureData value may need to be resized or recreated if this value is changed. Defaults to 0.

PySide6.QtDataVisualization.QCustom3DVolume.setUseHighDefShader(enable)#
Parameters

enable – bool

This property holds Whether a high or low definition shader is used to render the volume..

If this property value is true, a high definition shader is used. If it is false, a low definition shader is used.

The high definition shader guarantees that every visible texel of the volume texture is sampled when the volume is rendered. The low definition shader renders only a rough approximation of the volume contents, but at a much higher frame rate. The low definition shader does not guarantee that every texel of the volume texture is sampled, so there may be flickering if the volume contains distinct thin features.

Note

This value does not affect the level of detail when rendering the slices of the volume.

Defaults to true.

See also

renderSlice()

PySide6.QtDataVisualization.QCustom3DVolume.sliceFrameColor()#
Return type

PySide6.QtGui.QColor

This property holds The color of the slice frame..

Transparent slice frame color is not supported.

Defaults to black.

See also

drawSliceFrames

PySide6.QtDataVisualization.QCustom3DVolume.sliceFrameColorChanged(color)#
Parameters

colorPySide6.QtGui.QColor

PySide6.QtDataVisualization.QCustom3DVolume.sliceFrameGaps()#
Return type

PySide6.QtGui.QVector3D

This property holds The size of the air gap left between the volume itself and the frame in each dimension..

The gap can be different on different dimensions. The values are fractions of the volume thickness in the same dimension. The values cannot be negative.

Defaults to QVector3D(0.01, 0.01, 0.01).

See also

drawSliceFrames

PySide6.QtDataVisualization.QCustom3DVolume.sliceFrameGapsChanged(values)#
Parameters

valuesPySide6.QtGui.QVector3D

PySide6.QtDataVisualization.QCustom3DVolume.sliceFrameThicknesses()#
Return type

PySide6.QtGui.QVector3D

This property holds The thickness of the slice frames for each dimension..

The values are fractions of the volume thickness in the same dimension. The values cannot be negative.

Defaults to QVector3D(0.01, 0.01, 0.01).

See also

drawSliceFrames

PySide6.QtDataVisualization.QCustom3DVolume.sliceFrameThicknessesChanged(values)#
Parameters

valuesPySide6.QtGui.QVector3D

PySide6.QtDataVisualization.QCustom3DVolume.sliceFrameWidths()#
Return type

PySide6.QtGui.QVector3D

This property holds The width of the slice frame..

The width can be different on different dimensions, so you can for example omit drawing the frames on certain sides of the volume by setting the value for that dimension to zero. The values are fractions of the volume thickness in the same dimension. The values cannot be negative.

Defaults to QVector3D(0.01, 0.01, 0.01).

See also

drawSliceFrames

PySide6.QtDataVisualization.QCustom3DVolume.sliceFrameWidthsChanged(values)#
Parameters

valuesPySide6.QtGui.QVector3D

PySide6.QtDataVisualization.QCustom3DVolume.sliceIndexX()#
Return type

int

This property holds The x-dimension index into the texture data indicating which vertical slice to show..

Setting any dimension to negative indicates no slice or slice frame for that dimension is drawn. If all dimensions are negative, no slices or slice frames are drawn and the volume is drawn normally.

Defaults to -1.

PySide6.QtDataVisualization.QCustom3DVolume.sliceIndexXChanged(value)#
Parameters

value – int

PySide6.QtDataVisualization.QCustom3DVolume.sliceIndexY()#
Return type

int

This property holds The y-dimension index into the texture data indicating which horizontal slice to show..

Setting any dimension to negative indicates no slice or slice frame for that dimension is drawn. If all dimensions are negative, no slices or slice frames are drawn and the volume is drawn normally.

Defaults to -1.

PySide6.QtDataVisualization.QCustom3DVolume.sliceIndexYChanged(value)#
Parameters

value – int

PySide6.QtDataVisualization.QCustom3DVolume.sliceIndexZ()#
Return type

int

This property holds The z-dimension index into the texture data indicating which vertical slice to show..

Setting any dimension to negative indicates no slice or slice frame for that dimension is drawn. If all dimensions are negative, no slices or slice frames are drawn and the volume is drawn normally.

Defaults to -1.

PySide6.QtDataVisualization.QCustom3DVolume.sliceIndexZChanged(value)#
Parameters

value – int

PySide6.QtDataVisualization.QCustom3DVolume.textureData()#
Return type

QList

This property holds The array containing the texture data in the format specified by textureFormat ..

The size of this array must be at least (textureDataWidth * textureHeight * textureDepth * texture format color depth in bytes).

A 3D texture is defined by a stack of 2D subtextures. Each subtexture must be of identical size (textureDataWidth * textureHeight), and the depth of the stack is defined by the textureDepth property. The data in each 2D texture is identical to a QImage data with the same format, so bits() can be used to supply the data for each subtexture.

Ownership of the new array transfers to the QCustom3DVolume instance. If another array is set, the previous array is deleted. If the same array is set again, it is assumed that the array contents have been changed and the graph rendering is triggered.

Note

Each x-dimension line of the data needs to be 32-bit aligned. If textureFormat is Format_Indexed8 and the textureWidth value is not divisible by four, padding bytes might need to be added to each x-dimension line of the data. The textureDataWidth() function returns the padded byte count. The padding bytes should indicate a fully transparent color to avoid rendering artifacts.

Defaults to 0.

PySide6.QtDataVisualization.QCustom3DVolume.textureDataChanged(data)#
Parameters

dataQList

PySide6.QtDataVisualization.QCustom3DVolume.textureDataWidth()#
Return type

int

Returns the actual texture data width. When the texture format is Format_Indexed8 , this value equals textureWidth aligned to a 32-bit boundary. Otherwise, this value equals four times textureWidth .

PySide6.QtDataVisualization.QCustom3DVolume.textureDepth()#
Return type

int

This property holds The depth of the 3D texture defining the volume content in pixels..

Defaults to 0.

Note

The textureData value may need to be resized or recreated if this value is changed. Defaults to 0.

PySide6.QtDataVisualization.QCustom3DVolume.textureDepthChanged(value)#
Parameters

value – int

PySide6.QtDataVisualization.QCustom3DVolume.textureFormat()#
Return type

Format

Returns the format of the textureData property value.

PySide6.QtDataVisualization.QCustom3DVolume.textureFormatChanged(format)#
Parameters

formatFormat

PySide6.QtDataVisualization.QCustom3DVolume.textureHeight()#
Return type

int

This property holds The height of the 3D texture defining the volume content in pixels..

Defaults to 0.

Note

The textureData value may need to be resized or recreated if this value is changed. Defaults to 0.

PySide6.QtDataVisualization.QCustom3DVolume.textureHeightChanged(value)#
Parameters

value – int

PySide6.QtDataVisualization.QCustom3DVolume.textureWidth()#
Return type

int

This property holds The width of the 3D texture defining the volume content in pixels..

Defaults to 0.

Note

The textureData value may need to be resized or recreated if this value is changed. Defaults to 0.

PySide6.QtDataVisualization.QCustom3DVolume.textureWidthChanged(value)#
Parameters

value – int

PySide6.QtDataVisualization.QCustom3DVolume.useHighDefShader()#
Return type

bool

This property holds Whether a high or low definition shader is used to render the volume..

If this property value is true, a high definition shader is used. If it is false, a low definition shader is used.

The high definition shader guarantees that every visible texel of the volume texture is sampled when the volume is rendered. The low definition shader renders only a rough approximation of the volume contents, but at a much higher frame rate. The low definition shader does not guarantee that every texel of the volume texture is sampled, so there may be flickering if the volume contains distinct thin features.

Note

This value does not affect the level of detail when rendering the slices of the volume.

Defaults to true.

See also

renderSlice()

PySide6.QtDataVisualization.QCustom3DVolume.useHighDefShaderChanged(enabled)#
Parameters

enabled – bool