Lighting/Shadow issue with one sided models in UDK

[Tharapita]

First, if this is the wrong place to ask, sorry, the forums are rather confusingly laid out and I didn't know where else to ask.


But to the point. So I've made a model in Blender with just one side (the inner side, the outer is deleted since it's not meant to be seen) and when I put it into UDK, compile the light and all that, I get light and shadows casting through it:

(the shadows on the bottom edges and the whole interior being magically lit when it should be blocking outside light)

https://lh3.googleusercontent.com/-8.../s800/HWf1.png

Obviously not what I want.

How do I make it so that it wont let light and shadows through? It's been bugging me for a long while and I finally thought I'd just give up and ask since I can't find any way to fix it.


Thank you for any help, and bare with my inexperience.

[Xenobite]

use 2 sided material
or
add some simple geometry that will block light from outside /better option/

[Odedge]

I think Xenobite's second suggestion is best. Just wondering if the 2 sided material works (never tried it). Another thought... will you be adding more assets that might blocking the the light? The light should be coming through the invisible side of the mesh. While you can probably make the normal double sided, that might cause other issues.

Being a fellow Blender user, I dig what you have modeled. Any change on sending the Blend file for "educational purposes"? I haven't done any advanced modeling yet and could use the insight.

[Tharapita]

Hmm yeah I considered just blocking the light on my own but I was hoping there was another way, bit disappointed with that then. ah well. I'll just have to settle then.


As for the hall, it's a weeks old set of test assets (just thought they'd showcase the issue better than newer ones) and I didn't make them in Blender. I modelled them in Wings 3D then used Blender to optimize, uv-map and export into UDK. I'm not comfortable with Blender ; P

If you still want the file I'll try find it on my PC, I don't see why not, just hook me up with a filehost and I'll oblige.


Thanks for help though, both of you, I'll figure out something alternative then.

[Odedge]

If you can find, it would be nice to check it out (in a format Blender can read). Out of curiosity, why would you model in 1 program, then tweak in another?

[Xenobite]

usualy when you render your mesh in 3d app double sided material is on by default
since it would be better to use single sided materials for better performance in udk you have to add some (very simple) mesh that will block lights

for example if you have a hall with few windows you will have to put some kind of simple "tunnel" mesh around with few holes for windows

you can export your current scene /level into your 3d app so you can use that one as reference

tip: next time you model stuff use single sided materials for test renders and you will see (and you can fix) all problems before exporting stuff to udk

[Tharapita]

The files (from Blender 2.4 era, so quite old indeed) http://www.mediafire.com/file/u5tu05...estPieces1.rar

As for why, I've been using Wings 3D a lot longer and I find Blender too uncomfortable to navigate and use effectively for what I need. I could always adapt to Blender but it would take a fair few months to get as comfortable for little gain. Wings 3D also has a less than satisfactory range of supported file formats and UVmapping tools so I use Blender for those.

Again, just personal opinion and preference.


*EDIT* Thanks Xenobite, I'll keep that in mind.