Blender Alpha Channel

Posts

• Sphynx195 Posts: 461Member

  December 2006 #2

  

  Are you talking about using the alpha channel in a texture / background to let other things through in transparency, or are you talking about the alpha channel produced as a part of the rendering process?
  
  There are several areas where an alpha channel is used (as in most 3D apps) - what you want to do will influence the answer.
• [Deleted User]2 Posts: 3Member

  December 2006 #3

  well im wanting to be able to but a wire srenn type thing over an engine and then have light still come through.
  
  i would also like to be able to render my object with no background so i could just paste the image over a bacground later.
• Sphynx195 Posts: 461Member

  December 2006 #4

  

  Two ways that you can use tha alpha map for the screen (I am assuming that said screen is going to be a bit map). Create your image and an alpha image then load them both as an image texture. Set the one as colour, and the other to apply to alpha settings (the A setting will give your the overall alpha amount).
  
  A slightly easier method allowing you to work witha single map is to create a transparency capable image (such as a TGA or PNG image), load it as a single map onto the texture but ensure that the 'calculate Alpha' settings are turned on on the image settings panel (where you originally loaded the image).
  
  In theory, Blender renders with an alpha layer anyway - when you get your render on screen, press 'A' in the render screen and it will switch back and forth between the colour image and the alpha. As long as you save again as a file format that caters for alpha (such as a TGA in RBGA mode, or a PNG) the alpha layer should be available to you when you load it back into Blender as an image, or into an art package.