Seems lightning error

downarmy

Hi

i got this wonderfull seem bug where the light hit the seems it does a big dent in my geo and its driving me crazy...




right on top of the body....

any help polycount ur my only hope!

downarmy

i read on the internet its a normal map bug... am i on the right track?

Eric Chadwick

What software? Realtime or rendered? What are your shader settings?

downarmy

3d max 09 rendered whit mental ray

Eric Chadwick

Still vague, need more info.

How did you bake the normal map?
What does the normal map look like?
How is your material set up?

downarmy

no normal map


whit normal map


the normal is for the panel and rivet(wich are not done yet)
but at the seam on top its sopposed to be flat...

downarmy

my uv seams


my normal map

downarmy

think i might have to bake it...

Eric Chadwick

That looks fine so far.

What is your material setup? (what material type, exactly how and where is the normal map plugged into it)

downarmy

basic material

normal map in bumpmap 100%

Eric Chadwick

Are you using a Normal Bump map type in the Bump Channel? Is the Method set to Tangent? Are any of the Channel Directions set to Flip?

Michael Knubben

I suggest you check how this looks in a shader (xoliul's shader can be found right here on polycount and is really good) to see if we can't eliminate the shader as a possible problem (although I suspect that that's in fact where the problem might lie)

Eric Chadwick

Also... when you say "basic material" do you mean a Standard Material? A Standard renders fine here with MR, though I'm using Max 2010.

PredatorGSR

Well I'm guessing it is because your fuselage uvs are flipped. If they were correct, they should be facing in opposite directions, but right now they are both pointing the same way. I'm guessing you uv'ed half of it, duplicated and flipped in 3d space, but left the uvs the same. The uvs need to be flipped as well to match the geometry. Unfortunately the bad news is that this is going to majorly affect the uv layout, so you'll probably have to redo the layout. Make sure that you do this for every piece that you have flipped.

I don't have a lot of experience doing mirrored normal maps, but my understanding is that special coding is required (i.e. a game engine), in order to use them correctly, otherwise you get a seam and incorrect lighting. Otherwise, the uv shell can be flipped as long as it is a separate object, for example of you have multiple separate bolts, each bolt could use the same normal map with flipped uvs without issue (as long as the geometry and uvs are both flipped), but it is when you have half an object with a seam that you run into issues. I'm not 100% sure about this, so someone please correct me if I'm wrong.

Also, just in general, if you are using this full 1k texture on the plane with unique uvs, it is probably worth the time to make a hp model to get the most benefit from the normal map.

You can also check your model to see if the uv shells are flipped by going to Edit UVW window > Select menu > Select Inverted Faces.

Eric Chadwick

Hahaha, OMG I'm such a noob. Good catch!

downarmy

thanks predator that makes a lot of sense i dunno what i will do... i might reflip them back

Eric Chadwick

PredatorGSR wrote: »

it is when you have half an object with a seam that you run into issues. I'm not 100% sure about this, so someone please correct me if I'm wrong.

You shouldn't have any problems doing this when you're rendering in Max, either with scanline or mental ray. In the viewport is another matter though, mirroring always seems to create a seam in the viewport.

Unreal has a special hack, similar to what I've used in a different custom engine, where the artist assigns a 2nd UV channel that isn't mirrored, and the engine will then erase the seam from a mirrored normal map. There is a big limitation though... the mirror seam must be vertical in UV space. Any other angle will still create a seam.

downarmy

i refliped the uvw same result....

Raider

that always happens to me when i simply mirror the object after the texture, they share the same UVW space, there's a thread somewhere on this forum which shows a way to deal with it., but i can't remember where, i've always just tried to avoid and and not use mirroring.

Eric Chadwick

I updated the Mirroring section here.
http://wiki.polycount.net/Normal_Map#Mirroring

Still working on it, but what's there might help...

Anuxinamoon

did you normal map all of it at once or half at a time? Is your high poly only one half?

Eric Chadwick

No high-poly there, looks like a painted nm to me. Except for the wheel.

downarmy

i am just gonna say reset xform is your friend after a week of debuging...

it done the trick i got no idea why!

Anuxinamoon

downarmy wrote: »

i am just gonna say reset xform is your friend after a week of debuging...

it done the trick i got no idea why!

Oh yes! Always reset Xform after UV unwrapping.