Problem with two-sided faces in game mode? Normals?


I have a transparent model for a game/interactive I created, and the engine seems to have a problem with rendering an alpha on all of the faces. I have tried enabling and disabling two-sided, and it looks like it only succeeds in moving the problem around.

Here it is with two sided:

Here it is without:

Either way, the problem occurs at the transverse midline–some of the faces are invisible.

I don’t know whether normals would be to blame–I fixed anything that looked flipped long ago and it still looks okay in edit mode.

Under Edit>Texture Face, I have enabled Tex and Alpha, and Twoside in the first example.

Let me know if there is any other info I can provide.

Have you done a Remove Doubles? That (as well as any kind of intersecting faces) could be a problem. Otherwise, it’s just the Blender-can’t-alpha-sort-properly issue again.

I did a remove doubles, and there wasn’t anything to remove, so I’m good there. I’m not familiar with the “can’t alpha sort properly” thing–is it unfixable? Do you know of a link/thread I could investigate, or better yet, an alternative?

Sorry about my lack of knowledge on this issue.

I had some problems like this… trouble is I found it difficult to recreate them in a simple way for the bug tracker… got side tracked and didn’t report it.
Just in case, you know that alphas are calculated in relation to the centre of the objects - this should not affect you as it look s like you only have one object. You could try ‘center new’ and see if that helps.
Maybe post a blend?

what version of blender are you using?!..

I am using blender version 2.47.

I tried “center new” and I didn’t notice a difference.

Here is a download link to my file:

(The model in question is on layer 1–I have other models on layers 2 and 3, but they are good to go.)

The issue your having is an error with blenders alpha sorting. If you need to fix it the apricot builds sort alpha differently which should remove the problem. The error occurs in all official versions of blender and you cant do much to fix it in them. You can find the apricot builds at , they also support glsl which might make your project look better anyways.