sets the display object's <code>blendMode</code> property to <code><a href="../../openfl/display/BlendMode.html#SHADER">BlendMode.SHADER</a></code>. If the <code>blendMode</code> property is set to <code><a href="../../openfl/display/BlendMode.html#SHADER">BlendMode.SHADER</a></code> without first setting the <code>blendShader</code> property, the <code>blendMode</code> property is set to <code><a href="../../openfl/display/BlendMode.html#NORMAL">BlendMode.NORMAL</a></code>. Not supported under GPU renderin