Getting regions to render on both sides in orbit views

Is it possible to force regions to render on both sides in accelerated
3D views in 2004? It seems strange to me that they don't, as 3D faces &
lines with a thickness both render on both sides.

 

Is it possible to force regions to render on both sides in accelerated

I don't know. Couldn't find anything in help. But that's no guarantee.

Programmers did have to do extra work to make the other things two sided.
Perhaps it was just a choice to make regions more... ... "pedestrian so
far as 3d programmers are concerned."

 

Is there even any easy way to flip the orientation of them - or to
determine what the orientation will be when a set of lines are converted
into a region?

 

Is there even any easy way to flip the orientation of them - or to

I have a couple ideas. I check...

OK, the computer graphics answer would be "to see the shape, draw counter
clockwise." This does not appear to be AutoCAD's (2002) answer.

AutoCAD's answer appears to be "visible face is determined by +Z in the
UCS."

I tried to confuse it by making a bunch of little regions then flipping them
then unioning a bunch and the resulting region pointed up correctly.

If you need to flip the orientation of a region you can mirror it "through
its plane". Um... create your region on the ground, XY plane in world UCS.
Switch to Front UCS then mirror region about X axis. Delete original. Region
stays in place but now faces the other way.

If this were 3ds, you'd be able to extrude the region by 0 and make it a
solid. But this is AutoCAD and it demands a non-zero extrusion.

Which brings up the question of why you are worried about the orientation of
your regions. Are you sure this is the way you want to model? I know there's
a ton of different ways to use AutoCAD for 3d so maybe yours _is_ good for
you.

 

This is an interesting point though, & giving it a very small extrusion
migt be enough to fix the problem quickly when it occurs

Thanks for all the suggestions. Below is an explanation of how the
models are being created at the moment.


For the last eight years or so I have tried to avoid using AutoCAD for
3D as it annoys me so much for a wid range of reasons. I have instead
usualy tended to use Microstation (This is not to say I do no 3D work in
AutoCAD, or am unaccustomed to it - I just try & avoid using it wherever
possible). Some of the models go through to 3DS Max for rendering
eventually - via DWG format, but this is not a problem as Max will
interpret the regions correctly.
However, someone else that I work with wants to set up the models as
shaded orbit views in AutoCAD so that they can be rotated on screen
while he is showing them to a client (yes, there are other ways of
achieving this, but he wants to do it in AutoCAD as that is the program
he is familliar with). In Microstation it is very easy to create complex
surfaces (a lot easier than Acad anyway) so there is a higer number of
regions in the exported files than you might get in a file purely
modelled n AutoCAD.
Microstation is very flexiblever its export options though, & does allow
the creation of shapes as 3D faces, rather than regions - but this
involves setting the accuracy for curves, & also makes the model a lot
more awkward for someone else to edit IMHO, as many of the faces ave
invisible edges & then they are grouped into blocks.

I still see this treatment of regions as single sided as odd behaviour
by AutoCAD, & I would far prefer to find a way of displaying them
correctly in shaded views than altering the technique used to create my
models.

 

This is an interesting point though, & giving it a very small extrusion

If you are going to be going into solids later, this will piss you off. If
you are keeping to various flat "panel" thing (region, 3dface) it should
work ok. It might be a performance hit.

 

In Options - System - Properties - Geometry, uncheck Discard back faces to
shade both sides in viewports

To render both sides, click Render - More Options - Face Controls, uncheck
discard back faces.

 

In Options - System - Properties - Geometry, uncheck Discard back faces to

Dang.

Thanks.

 

I only just saw your message after being away from internet connection
for a few days.
Many thanks for finding the solution to the problem - I imagined that
there had to be a setting somewhere that would control this, but did not
find it anywhere when I was searching through the settings.
Thanks again.