How to Get a Background Image with Cycles and HDRI Map

Support Compositing and Post Processing
1

Just wondering how to do a background image with cycles. I am using ENV HDRI lighting and a sun lamp to light the scene. The HRDI map provides a background, but it’s scale is very large. I want to place a differnt background in tehe scene but keep the HRDI lighting. Normally in BI it would allow me to do an AlphaOver node in compositor. How can I do this in Cycles with an HDRI map?

Any help is appreciated.

2
  1. Make background transparent by check “Tranparent” in Render setting > Film
  2. Make another scene with “blender render engine” and render your only prefer background.
  3. Composite them together

PS: I’m a newbie. Hope it work, apologize if not.