Blender: Double Sided Mesh

[Pamela Galli]

Should the Double Sided Mesh be checked by default?  What is it for? 

[Aquila Kytori]

Do you mean this :  

  

and if so are you asking is it checked by default then the answer is yes. It has always been checked in all the meshes you have ever made so don't worry about it .

The answer to your second question is yes as well, now stop asking silly questions and get back to work .

 

[Gaia Clary]

In second Life: polygons have always only one side. The opposite side is always not rendered and thus appears fully transparent.

In blender: you can tell the render engine to treat polygons as opaque from both sides. The render option "Double Sided" is enabled by default because this is in most cases exactly what you want when rendering. This option has no impact(afaik) on the 3D View. And it has definitely no impact on how themesh is transported to Second Life. So you can just forget all about this option unless you use Blender for rendering as well.

However i believe "Backface Culling" may be of higher value for you (You find it in the properties sidebar of the 3D View (in the Shading tab):

Enabling Backface Culling tells Blender's 3D View to behave similar to how the SL renderer operates, i.e. when this option is enabled, then polygons are displayed opaque from one side and transparent from the other side.

[Rahkis Andel]

The double sided option does make a difference in the 3D viewport. Turning double-sided normals off on each object is a known method of speeding up a slow viewport in some cases.

When you turn double-sided normals on, it tells the 3D view to shade each side of the poly-face based on normal direction; the front side of the face will be shaded normally and the backface will have inverted shading. With double-sided off, both sides of the face will be shaded the same (So you won't be able to tell if there are flipped/messed up normals). With backface culling on, only the front side of the face will render at all (therefore having double-sided on in this case has no effect, so it may as well be off).

So long story short, Gaia is right that you may be better off having double sided off and backface culling.

[Pamela Galli]

Thanks to all!  Sometimes I get paranoid about what I have checked or not checked, and not without cause.

 

Aquila, I suspect I have been known for the last 6 years as that silly woman who asks all these silly questions in forums. Why quit now?  :matte-motes-kiss:

[Chellie Sholokhov]

I see what you are talking about here. But I am trying to figure out how to make it visible in world when it shows up invisible on the other side. Could you explain how to make it look like as it does in blender when the backface culling isn't activated? 

[Pamela Galli]

You can use Solidify in the Faces menu (>Mesh in Edit mode)