Issues with normal maps in game engine (Asset Editor)

[Fegus]

UPDATE: The issue is solved! For a basic explanation, see my latest message posted below.

Greetings, Paradox community. Newcomer here.

I've been making an original apartment building to import in Skylines (3Dmax for meshes and UVW coordinates, PS for textures and maps) and so far the workflow has been good. Until I noticed my normal maps weren't really working in the game engine.
I was wondering how many other people have encountered troubles like this with their normal mapping, so I've come here to see what I can find.

I took some screenshots to illustrate the specific issue, because I think the images will better explain what's going on, rather than me expanding only with words about an issue so strange.

First off, my building. This is where I noticed the missing "bump" effect of the stoney areas on its sides. Marked those with red in the screenshot.
All the stoney tiles should be showing the same bumpy effect as is visible on the inner top portion, marked green. And I assure you, the normal map is covering with bumpiness every portion of the tiled texture.

Notice the light-source angle on both parts, bugged and functioning, is exactly the same. So both should be showing the normal maps' rugged surface.

So, having seen that, and finding myself super confused as of what was going on, I decided to go back to the start and make some tests.
For this I used a totally basic gray cube, normal-mapped with a basic segmented sphere (with the color axis aligned to those I find working on Skylines environment, going by experience) printed on every surface. The result was positive on the "roof" face, but as you'll see... the "bump effect" on each side was showing very broken.

Notice the sides are showing practically featureless, beyond the broken bits of their top portion. Very strange... And I repeat, all sides were mapped around the same normal map, same area. A basic segmented sphere.
Another sample from the test:

The maps are all saved in PNG format, 8-bits. Diffuse, alpha, specular, have all worked correctly in my building import. The normal map turns to be the odd one.

So... does anybody have any idea what's going on? I would super appreciate if someone from CO reads this, too. :')
BTW. You guys, and Paradox crew, are awesome. Thank you for bringing citybuilders back to (a decent) life!

 

[KR153]

Welcome dear sir and join the club!
That is really one nice model you have there. I have some good and some bad news:
The good is, you are not alone. The bad is, it seems like this is how it is... I had to smile a bit, because what you did is nearly exactly what I did. With the same results, only that I had even more problems with the saturation of the diffuse map.
To demonstate my point I have made some comparison shots CSL/CXL that shows pretty well how poorly normal maps are handled by this game. It never creates a sharp relief when it should, it just looks "ripped off" on the edges and is overall not very distictive.
I posted this before but I guess it fits here quite well. Take the two big red neons on the roofs for example. On the top picture (CSL) it just looks like painted metal or something. Below (CXL) it has all the nice details, it actually looks like it would have some structure and that is exactly what a normal map is supposed to do.
You can compare every part of that buildings where a normal map would have to take effect. In CSL it is just.... not there. FYI: They are the exact same models, the exact same texture maps and all.
http://i.imgur.com/eCcWsRq.jpg
http://i.imgur.com/0SWYpuV.jpg
http://i.imgur.com/OSn5EG8.jpg

Of course there is still the possibility that I do something wrong here, given my limited knowledge of the deeper matter, but somehow I doubt that.

 

[Fegus]

Hey, KR. Thanks for replying! (and sorry I was a little slow in return)

Yeah, it's... quite strange, isn't it? I still understand Skylines' rendering isn't aiming to be as (apparently) sharp detailed as CXL was, since we have here a working engine that actually... works. CXL's was pretty in small scale, yes, but as soon as the city grew into an interesting size, things went very stale in graphic performance.

But yeah, back to topic, is difficult to think there's something left out, that we might be doing wrong. Something inside the engine as is, isn't quite taking our normal maps as is to be expected. I wish CO would throw some light on this soon. :^0

 

[KR153]

I wish CO would throw some light on this soon. :^0

That would be awesome, because most what I get here from other members is the heretic treatment. One major improvement gave me this here (I hope you have an Nvidia cart?):
[video=youtube;EARHpaCB538]https://www.youtube.com/watch?v=EARHpaCB538[/video]

Didn´t know about that, wasn´t necessary until now. You should also try these three mods:
http://steamcommunity.com/sharedfiles/filedetails/?id=410805639&searchtext=
http://steamcommunity.com/sharedfiles/filedetails/?id=410329674&searchtext=
http://steamcommunity.com/sharedfiles/filedetails/?id=408932281&searchtext=
Overall great improvement, although it is still much too bright where direct sunlight hits and it burns the diffuse. Let´s see where we are in a few weeks from now...

 

[Fegus]

Haha... nope. ATI Radeon graphics here. I can poke around similar options to that nVidia software, with Asus' own sofware, so I will try.
But overall I -really- like the graphics in Skylines as they come from factory. I think the balance between detail and performance is the nearest to perfect I've seen so far, for games of this nature. My happiness is abundant about it.

If only our custom normal maps would work, tho... :^]

 

[KR153]

The improvements I mentioned were in the normals as well. I hope you get it to run with your card.
Another thing I tried was that I sometimes flip the colours of special parts of my texture before I convert it to a normal map.
Godspeed.

 

[Bipin]

I see that I'm not the only one experiencing these issues. I had thought it was a problem with my maps, which it apparently is not. I took a map that was proven to work elsewhere (the brick is located here: http://www.mapcore.org/topic/1086-totally-random-texture-thread/page-197) and imported it into the game

Sometimes the normal map displays correctly, or not at all.

Somtimes though, it displays with opposite depth. That grout between the bricks should of course be recessed. Quite frustrating.

 

[Fegus]

Bipin:

Yes, that issue of inverted depth, that's something I found too! Apparently, the game engine (at least inside the Asset Editor), has been rendering our normal maps using shifted coordinates, different from those used in normal maps elsewhere. Thru experimentation, I've found that a rotation of 90º clockwise (a quarter) will bring the normal axis to be oriented the way Skylines understand them (I will try to provide image samples of this in some minutes, on a full length post).

KR:

Thank youu!! I've accessed similar options in my AMD Catalyst software, so it would take care of textures rendering overriding the applications settings, and now the normal maps show perfectly. More even, is using just the common coordinates as is found in standard normal maps. No color/axis rotations needed.

 

[Fegus]

OOook. Guys. I figured it out.

Forget the rotation of the maps I mentioned before. And the broken/missing bumping effect, is also solved.

The key here is... the normal maps' rendering on the buildings totally breaks if you rotate the model inside the Asset Editor's importing dialog. Scaling works fine as is, but rotation doesn't.

So, Bipin, I am guessing you have rotated your model when you were importing it, in the Editor, as I did. You might need to return to your 3D modeling software, and produce this geometry rotation in there (but not its axes), before exporting to FBX. Then when bringing it back in the Asset Editor, scale it if needed, but leave the rotations alone. That should make it work as expected.

On a side note: apparently this has nothing to do with the Y-up setting required in the FBX. I've done that, as I think you have too, or else our models in the Asset Editor would look much worse (telling from experience).

KR153, again thanks for your tips. I'm trusting now we can choose to avoid those additional actions, like overriding the engine thru our graphics driver/software. At least the normal maps won't need that to work! If we take enough precautions exporting our models, that is.

Cheers everyone! Keep modelling!

 

[cinephile]

Thanks for the work chasing this issue down.

By don't rotate in the mesh/model importer, do you just mean, don't click those buttons for rotating around the axes in the preview window?

Very strange issue. This explains a lot of weird things I had been seeing with textures, though. I don't think I actually ever used those buttons to rotate my models, but I had been fiddling with them in the preview sometimes, and I think that also might have messed up some textures.

So yeah it seems best not to touch them.

 

[OlaHaldor]

I may be wrong, but I believe there's a difference between games using DirectX and OpenGL, thus the weird results one might get.

As far as I know, and I may be wrong here as well, but for the game to work on all platforms I believe it's OpenGL?

 

[Xannepan]

Did you report this as a bug... Thanks for figurimg this out! (Going to update all my buildings

 

[Fegus]

Cinephile:
Yes, I meant that precisely, those buttons. Today I finally finished my model importing, at it was a success after having done it without using those rotation buttons. We'll have to just make sure our models are facing the right way before exporting them into FBX files.

OlaHaldor:
Yeah... I think OpenGL is the one most commonly found across all OS platforms. But really not sure.

Xannepan:
Nu, I haven't reported it as a bug, yet. To be honest, it took me days to actually find out where the problem was laying, so for the most time I thought I was doing something wrong instead. On the other hand... while it does seem like a bug, it might as well derive from a limitation of the graphics engine? Of course I'm only guessing.

 

[Zed68]

I had to invert the red channel of my normal maps to make them work correctly with the game. Maybe it was due to the conversion tool I used but I think every builder should make a test to see if their normals display correctly in game with the tools they use.

 

[Bipin]

Thank you for figuring it out! Judging by the results and responses from others, this looks like a good method. I'll have to give it a try!