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/*!

\title Blend Mode
\page best-practices-blend-mode.html
\ingroup qt3dstudio-best-practices

This page describes the
\c{Blend Mode} property edited in Qt 3D Studio.

\image LayerBlendModes.png "Blend Mode"

The Blend Mode property controls how the colors of the active layer or object are blended with
the colors of the background layer or object.

In Qt 3D Studio both layers and object materials have the Blend Mode property. Changing Blend
Mode in a layer will effect all objects in that layer while changing Blend Mode for a single
object will only effect that object and it will only blend with background objects in the same
layer, not with objects in other layers.

Different blend modes are using different formulas to calculate the result as described below.
It is important to know that every color channel of a pixel has a value ranging from 0.0 (black)
to 1.0 (white). In formulas below \e A is the pixel color value of the active layer or object
while \e B is the pixel color value of the background layer or object.

\e{Note that modes marked with * are available only with hardware supporting KHR and NV
extensions.}

\section1 Blend Modes

\section2 Normal
For both layers and objects the default blend mode is \e Normal. Opaque objects will
occlude objects in the background.

\image LayerBlendModeNormal.png "Normal"

\section2 Screen
\e Screen inverts the pixel color values of both active and background layers or objects,
then multiplies them and finally inverts the product. This will produce a lighter result.
Black pixels in the active layer will be rendered as 100% transparent.

\b Formula: \c{1-(1-A)*(1-B)}

\image LayerBlendModeScreen.png "Screen"

\section2 Multiply
\e Multiply multiplies the pixel color values of both active and background layers or objects.
This will produce a darker result. White pixels in the active layer will be rendered as 100%
transparent.

\b Formula: \c{A*B}

\image LayerBlendModeMultiply.png "Multiply"

\section2 Add
\e Add simply adds the pixel color values of both layers. This will produce a lighter result.
Black pixels in the active layer will be rendered as 100% transparent.

\b Formula: \c{A+B}

\e{Note: Available only in Layers}

\image LayerBlendModeAdd.png "Add"

\section2 Subtract
\e Subtract simply subtracts the pixel color value of the active layer or object from the pixel
color value of the background layer or object. This will produce a darker result.

\b Formula: \c{B-A}

\e{Note: Available only in Layers}

\image LayerBlendModeSubtract.png "Subtract"

\section2 Overlay
\e Overlay uses a combination of \e Multiply and \e Screen modes. Basically it uses \e Screen
mode on lighter pixels and \e Multiply mode on darker pixels. This will produce a result with
increased contrast.

\image LayerBlendModeOverlay.png "Overlay"

\section2 ColorBurn
\e ColorBurn inverts the pixel color value of the background layer or object and then divides it
with the pixel color value of the active layer or object. Finally the result is inverted. This
will produce a result darker than with \e Multiply.

\b Formula: \c{1-(1-B)/A}

\image LayerBlendModeColorburn.png "Colorburn"

\section2 ColorDodge
\e ColorDodge divides the pixel color value of the background layer or object with the inverted
pixel color value of the active layer or object. This will produce a result lighter than with
\e Screen.

\b Formula: \c{B/(1-A)}

\image LayerBlendModeColordodge.png "Colordodge"

*/