One-sided surface normals

I’m making a scene in BGE, but the planes to make the leaves in my trees just render if the camera is facing the plane’s normal. In 3D View you can rotate the camera as you want, but in BGE, when you look to a object that it’s normal is “pointing” to the other side, the face disappear. It’s like the option “Double-sided” was deactived, but it is not. I tried to add the Solidify modifier to the leaves of my trees and check the option “High quality Normals”, but that slowdown the game a lot. Do someone know a solution?

Go to the texface options and select ‘two-sided’, make sure your object has a UVmap first.

In 2.49 you can then copy the property to all selected faces, 2.5 doesn’t have it hardcoded, but there’s an addon bundled with it that does that.

oooh it was hard to find the texface options, because i didn’t knew they were in mesh options, but THX! And, about the addon to apply the option in all the objects, what addon it is?


I wasn’ in home when i answered this, so now I saw that the “Two-sided” option in Texface options don’t make difference for the trees, the planes continue disappearing when I look they in the opposite side of their normals. Duplicate the faces is just impossible, the fps drops a lot. With other planes, check the “Two-sided” option worked, but to the tree planes, it doesn’t work. Could this be the same problem of: “” ?

i uploaded a video to show the problem, please sorry the bad quality. here is the link

Did you copy the setting to all selected faces? It doesn’t do that by default. Enable the Copy Settings add-on in the User Preferences menu (2.5) if it isn’t enabled already.

but select all the faces and click “Two-sided” isn’t enough?

Ahh… no wonder. I was looking for that! Thanks.

@andre - No, you have to select all the faces, click ‘Two-sided’, and then copy the settings with the ‘Copy Mode’ button, if I recall.

@mziskandar - No problem.

oooh now it worked, really THX!.. but… i’m not so happy… now it’s running at ~90fps… in fact bge isn’t good with z-transparecy, because when I look to the trees the fps drops drastically…
The problem isn’t with my trees, because to see if that was the problem, I extracted some trees of some games, and that slow the bge too. Z-Transparency isn’t so fast in bge… i’m almost desisting my demo, because the fps is very low to a so simple scene (on a NV GF GTS 450 overclocked…), because i’m using a lot of trees and also displacement mapping, but now i’m seeing that bge REALLY need A LOT of improvements…

Yes, if I recall, the BGE isn’t so good with Z-Transparency. However, it doesn’t sound bad at all - 90 FPS is quite high. For a game to maintain a constant 60 FPS is considered good nowadays - if a game dropped to around 20-30 FPS, it would be acceptable, as well. Basically, I was like you in that I wanted to ensure that I had enough leeway when it comes to FPS, but after playing some great games that don’t play at 60 FPS, I don’t care as much.