I’ve noticed that too, however I guess it’s not a solution. I know it’s beta ver however it’s still difficult to imagine it’s a bug - it’s so easy to reproduce… It basically means almost all basic renderings will have such annoying issue…
Your problem has to do with normals; If you flip the normals, the problem faces flip with it.
Blender is confused on which one is inside and which on is outside. You need to have at lease some thickness for blender to render the double face correctly.
adding a solidify modifier fixes this problem. I also added a subsurf modifier and edge split modifier to make it look nicer.
the one to the back right is the original, the front one is the fixed one
Thank you! That definitely clarifies a lot (and let me solve the issue). However, one more question - does it mean there’s a general rule in 2.5 (it didn’t work like that in 4.x) that whenever I have a semi-transparent mesh or the one which has a hole in it, it has to be thick? I have another example when the mesh is CLOSED (no holes) but it’s semi transparent (let’s say alpha=0.6) - in such a case the artifacts are visible also.
2.If your goal is to only view inside the mesh from the top, you don’t need transparency, and if you decide you want transparency in your scene anyway, it seems that “Z transparency” overcomes that “triangles” bug that we get with “Raytrace”.
Oh and Just a quick tip: you can use the Edge Split modifier to get rid of those “black effects” you get from setting “smooth”
*When I wrote “official 2.54 beta” I meant 2.54 beta from blender.org site.