Rough edges, alpha and small render size

Hi there,

I’m a complete beginner in Blender and I bet there’s a very simple solution to my problem. Still, I haven’t been able to figure it out myself.

I’m trying to render a tile image for a 2d game. Since I need tiles to be 46x96, I have to scale the rendered image at some point. After scaling, there seems to appear a blurred line on all outer edges, which makes the tiles look not seamless (attached image with red circle). What I’m doing is:

  1. render the image to 230x480 with no OSA and alpha set to KEY.
  2. scale the image to 46x96 in another application with smooth setting on. It’s exactly the same if I use blender’s scale node.

How can I fix this? I tried setting the render size to 46x96. Then, the edge problem is gone, but the quality is very low. I played with OSA settings, but all it did was it made the render blurred.

Attached Images:

  1. after scaling, alpha and blur on edges
  2. small render size - good edges but low quality
  3. before scaling, 230x480 - rough edges, OK!
  4. small render size with OSA - terrible


Rough edge you are seeing is the image pixels. When you reduce size of bitmap image you are going to start to see the pixels just like what you see.