Double Sided

CaseyB · Post by **CaseyB** » Mon Apr 03, 2006 10:41 pm

I am trying to make a model in Blender and I need to create a plane that can be seen by both sides. Picture the feet of a duck. I want to create the web between the toes. I put a single plane, but it was only visible from one side, then when I tried to put another Blender said that "These points already form a face." How can I get the "webbing" to be visible from both sides?

Chris Jones · Post by **Chris Jones** » Mon Apr 03, 2006 11:28 pm

place another face with its own vertices facing in the oposite direction?

CaseyB · Post by **CaseyB** » Tue Apr 04, 2006 1:21 am

I tried this and it cause weird results due to the depth fighting, so I tried to merge the corners and I ended up with just the one face again.

Bren · Post by **Bren** » Tue Apr 04, 2006 1:32 am

I was wondering the same thing when looking at the discussion on muzzle flash: http://www.ogre3d.org/phpBB2/viewtopic.php?t=19023

How are the double sided polys made? I realize all those screenies are from max, but what happens when this is exported to OGRE?

Maybe the depth fighting you see is a Blender issue, and it will be fine in OGRE? I don't know.

scotths · Post by **scotths** » Tue Apr 04, 2006 2:33 am

Bren wrote:Maybe the depth fighting you see is a Blender issue, and it will be fine in OGRE? I don't know.

I have that problem a lot when I view a model in the 3D window in textured mode in Blender. Usually, when it is exported to an engine it looks OK though. But I imagine this is not always predictable. This is the only way I have found to fake double-sided-ness.

Scott

Jerky · Post by **Jerky** » Tue Apr 04, 2006 2:57 am

http://www.elysiun.com/forum/viewtopic. ... ided+polys

CaseyB · Post by **CaseyB** » Tue Apr 04, 2006 3:03 am

That's perfect!! Thank you!!

reimpell · Post by **reimpell** » Tue Apr 04, 2006 10:32 am

The documentation that comes with the script wrote:

lonewolff · Post by **lonewolff** » Fri Jun 02, 2006 9:16 am

For those who dont want to follow the link you have to do the following;

Go into face select mode, select all faces, in the paint window hit 'twoside' and then 'copy drawmode'.

lonewolff · Post by **lonewolff** » Fri Jun 02, 2006 9:48 am

I tried this method.

For me it looks ok in blender but when exported, still shows up single sided in ogre and even in milkshape.

Anyone had this?

Post by **jacmoe** » Fri Jun 02, 2006 9:54 am

Try to disable culling in your material script:

Code: Select all

cull_software none
cull_hardware none

lonewolff · Post by **lonewolff** » Fri Jun 02, 2006 1:02 pm

That did the job.

But, I find now that if shadows are turned on and the camera is placed on the shaded side, there is flickering between the lit and shaded areas.

This mainly happens when the camera is relatively close to the object.

Any ideas around this? Or am I better off going for a proper double sided mesh?

I would prefer to avoid this, to keep polys as low as possible, as my intended scene will consist of many polys as it stands.

Post by **jacmoe** » Fri Jun 02, 2006 2:23 pm

I think you will improve performance by adding those extra polys, because it will minimise render state changes.

lonewolff · Post by **lonewolff** » Fri Jun 02, 2006 10:58 pm

Is this because of all the switching of culling on and off for different textures?