Normal map lighting issue

MattyWS

Hello all, I don't post here much but I know you all might have the answer to this problem. I will use a concrete barrier as an example.



To make this asset I modeled it in Max, made a high poly version and sent it to Zbrush where I applied a quick noise. From there I used Zbrush to render a normal map.

Now the problem is that one side is fine and the other is wrongly lit. This happens in UDK and Max and I am not sure why.



So I came here to see if you all know what's going on. For the record the normals are fine and each flat surface has it's own smooth group assigned to it.
Normal map is below



Any help is much appreciated, thanks!
MattyWS

MattyWS

Thanks for the reply, I have just tried starting off with the material only being diffuse, lighting was fine, I added the specular and lighting stayed fine, I then added the normal map and it messed up the lighting on one side again.

kwshipman

have you tried inverting the green channel?

tristamus

Map does look OK, but pass it through xNormal and see if you get different results?

Ace-Angel

Maybe one of the mesh sides is flipped?

MattyWS

I tried inverting the green channel and it came out the same, tried flipping the faces on the mesh and it came out invisible (expected).

I shall run it through xNormal now and see what shows up.

Ace-Angel

Before exporting out of Max, did you make sure to 'clean' it? Like select all the vertices and weld at a small threshold or reset XForm, etc?

Also, check you settings in UDK, make your sure you have NormalMap or NormalMap_Uncompressed in the settings for compression.

MattyWS

I just did a 'clean' and it was pretty much perfect as it was ^^. Exporting options from max i checked the boxes to;

Smoothing groups (was on by default)
Tangents and Binormals
Turbosmooth (was on by default)
Convert dummies to bones

MattyWS

Actually now looking back in max the issue no longer happens but still does in UDK >.< to further complicate things, sorry.

I tried doing RGB values of 128,128,255 again to make sure, no luck.

I completely removed all smoothing groups (which now clearly shows in UDK aswell, as the metal bar is not smooth) and unchecked all of the settings I mentioned above when exporting from max.

However still shows up with one side darker. I am thinking it's a mesh problem for sure though, since I accidentally applied the material to the floor in an attempt to drag/drop it onto the mesh and the floor came out fine. xD

Thanks for all the help btw guys, it's all very helpful

EDIT: Going to try exporting to .obj now and importing back to max as suggested~

Ace-Angel

Did you import the texture correctly? As in NormalMap compression?

AlecMoody

What exactly is the problem you are trying to correct? Are both the barriers supposed to look the same? Are they instances of the same object or is that one object sharing UVs? Duplicate polygons overlapping on the bright one?

MattyWS

Heh yea it seems like I'm an insane person but I'm pretty sure it was happening! :P

I'm gunna try inverting the normals on the face that's wrong and see how that looks but then even if that works it's not exactly a proper fix to the problem. Without a normal map the model's shading is fine, as soon as the normal is applied the shading goes wrong >.<

kwshipman

Ace-Angel wrote: »

Did you import the texture correctly? As in NormalMap compression?

This is a good point. are you sure you used the correct setting when you imported the texture? CE3 will have similar problems if the wrong crytiff setting is used.

MattyWS

Hello all ^^ Sorry for the lack of activity here, thank you all for the help, however I ended up just remaking it and so far the normal map is fine (it definately was the normal map causing the issue, as without it the model looked fine).

The only real difference in this new mesh is that the UV's are separated a bit. In the last one I tried to keep it to a minimal amount of UV elements. Could this have caused the lighting issues?

Ignore the hard edges in this one its not a finished product, however if anyone has any tips on rounding the edges a bit more that'd be great! I wanted to avoid just chamfering the edges lots but if that's the way to do it..