qgis/Quantum-GIS — pull request #475 by nyalldawson (2013-03-22 01:06:22+00:00)
Title: Add support for blending (composition) modes, eg Overlay, Mutiply, etc (#5248)

Adds support for blending modes for vector and raster layers. Allows for some fancy cartographic effects (along the lines of http://mapbox.com/blog/tilemill-compositing-operations-preview/)!

Works for all vector and raster layers, exporting maps and composers as images, and for exporting composers as pdfs IF "print as raster" is checked.

Todo: investigate if compositing is possible for standard pdf output.