Alpha transparency not working

Component:Blender Exporter
Category:bug report

Alpha channel

I've tried on Mac OSX, and Window 7 64 bit, both with 2.62 and Yafaray 0.1.2 combo.  I've tried using the existin alpha channel as well as a separate Diffuse and Alpha channel.


Alpha mapping not workingMaterial settingsDiffuse


I've tried with images that contain an alpha channel and this doesn't work

LeafAlphaProblem.zip355.84 KB




Assigned to:Anonymous» Olaf
Status:active» by design

I have updated your blend.file. So now it works fine here with latest exporter and Blender CVS:



updated .blend:


HTH, Olaf.


Hi Olaf,


   There is still strange behaviour even after your updated file.  In order for this to work you have assigned the BW image to translucency but it needs to use a negative value (-1.00).

  I tested the use of a single image texture with included alpha channel (.png) and something else bizarre happened.  If I select "use alpha" and set a positive (1.0) value in the transparency I get an inverted result (the centre disappears).  When I uncheck "use alpha" it works but leaves a premultiply type of result with the material fringes on the edges.

  Finally if I check "use alpha" and then use a negative (-1.0) transperancy value all is well with a single channel.  Funny behaviour which should likely be addressed since it's quite confusing.


thanks for looking.


Status:by design» closed

I cannot see anything strange in the latest versions. Closing...