I have a tree with some alpha mapped leafs. it looks amazing using GLSL Materials. Only, when I press “p” I only see the polygons normal facing side. how do I get them to be double sided? Double sides is Checked in the object Data tab.
To make it visible from both sides you got to select “Two-side” in the texture face panel (it only appears when you are in edit mode and you are in “blender game”)
Like this:
When you use two-sided in GLSL mode, the lighting is not recalculated for the second side. Blender Materials mode handles the lighting properly for two-sided. Probably this is a bug that someone should report…
On my macbook pro in 2.53 in GLSL mode as long as you have twoside enabled on the face in the face settings (which has to be assigned per face manually since there’s no copy button yet), as well as doublesided enabled under Normals (same tab, but you don’t have to be in edit mode) it shades twoside faces properly in game- but it still doesn’t shade correctly in preview. Perhaps because in preview it has to use the mesh normals, whereas while the game is running it has the freedom to flip the normals toward the camera.
It seems the bug only occurs when there is a Blender material assigned to the object.
Please test the attached file. The two planes are identical, except that their normals have opposite Z orientations. For me, the lighting for each plane is the same on both of its sides, and it is the lighting from the side which has the normal.
Steps I used to create:
Delete default cube, add plane.
Assign a Blender material to the plane
Edit mode, U Key to unwrap.
Double sided is selected by default.
In Object Data >> Texture Face, select “Two-Sided”.
Set game render mode to GLSL.
(I’m using 2.53+ (rev 31447) from graphicall (Fish’s build, 1112 here). 32bit on Linux Mint 9, GeForce 9800 GT. Problem exists in offical 2.53 Linux 32 bit build from blender.org and persists in rev 31447 built today.)
Attachments
twoside-GLSL-2.53.blend (426 KB)
I can confirm the bug, and that it’s only present when there is a material assigned.
This looks like good news for everybody. I figured out how to make polygons double sided in the game engine (Thanks!), and we reported a bug. Is there any way to find out when or even what build would have the bug fixed? Other than downloading one every day and testing it. I’m trying to write a tutorial on making a realistic tree, but I would like to wait until this bug is fixed, before I publish it.
Well, all of the currently reported bugs are on the tracker here:
https://projects.blender.org/tracker/?func=browse&group_id=9&atid=306
You have to register on the site to view reports. Once you do, go to the bug report itself (the link in my post above) and click “Monitor” (the one by itself with the mail icon next to it, not the one next to “Reporting”). You will receive email updates when developers respond to the bug.
Keep in mind that Blender development is done by volunteers, and the Game Engine development team is rather small, so it may be a while until a build with the bug fixed is available.