I dropped a square and put it at 0,0,0. Here’s where it ended up:
I took MostHost_LA advice and deleted, and re-imported the object back into the scene. The lines came back, but I got this error message:
When I looked at the doc, it said this:
I think this was the problem all along. What do you all think?
Ok, looks good.
Large actor casting shadows, hmm, probably not. That error usually refers to giant things like a sky sphere.
If the crosswalk is flat, and the road is included i would just disable shadows on the object altogeter.
It needs to receive them, not cast them.
Either way, it goes back to the issue being the UV or the UV being used in the material.
You havent shown the material setup yet. And if you look at the fact that world grid on this object has no grid - you know for sure the UVs are an issue.
Share the latest fbx, i’ll have a look too.
Sure thing. Here’s the updated model:
sideWalkAndRoad.fbx (405.5 KB)
This looks like a problem only when I have the object as a blueprint actor. I don’t get the lines when it’s a static mesh.
It just made me curious since that’s what the message said. Several of my models have errors of some kind when I first imported them into Unreal Engine 5.32 as well.
I always get the smoothing group error.
It’s gone. IT’S GONE!!!
I took your advice and turned off “cast shadow” on it’s mesh, and the lines are GONE!!!
I even have a skylight in the scene.
This looks like it works. I never thought of not having shadows on the ground, cause, you know, shadows are everywhere where there’s light. I made sure all of the models are stationary while I was at it.
Stationary vs dynamic likely had more impact.
But yes, the floor needs to receive shadows, not cast them - unless there is a specific reason for them to cast shadows.
The smoothing group error just has to do with the fbx export settings - if the object doesnt need to be smooth faced it probably can be ignored.
Let me review the mesh anyway…
Ok, so here is your UV Map:
that’s pretty bad - you never want anything to go non perpendicularly because it will distort and pixelate.
This is the model (as you obviously know):
It’s fairly bad, too many tris for what it is. It’s not a Huge deal yet - if that’s all there is in your scene, but it’s not really the way to go about modeling “large flat surfaces”.
The azure lines are sharp corners, so you must export the mesh with the proper smoothing groups for it to work.
You have 3 materials applied to the same mesh:
More importantly though. you have different texel density across the mesh:
Overall, areas like these:
You can literally remove all of that, and loose absolutely nothing:
As far as the lines go - they are indeed generated by your mesh topology and lighting.
You also have some weird areas to remove/check out
and quite a few tris where they would never be seen by anyone (so they can be removed, or at least reduced/culled:
Using a limited dissolve with an angle value of 1 degree + triangulating the mesh, will already improve your mesh significantly in about 15 seconds (30 if you have to go look up what this means):
1853 tris vs 6632
It is still a VERY high count for what it is, but you should have an easier time properly handling the UV:
Make sure to look up what texel size is, and how you are supposed to make assets with that in mind! 
And I’m pretty sure that even just with the described simplification you’d be able to get better lighting to hit the object and avoid generating those lines even without disabling the shadow casing.
On that - maybe separate the Curb out as a separate asset - and have it cast.
Okay, this is a lot to take in as I was taught in class to not have and triangles faces and n-gons on my 3D objects. That was in 2018. All of this I did in Maya, but I should have checked to texture sizes there with a UV graph I was given in class. I was taught to label all of my materials, regardless of them having the same material. Force of habit. Alongside of putting edges on the edges of 3D objects to make them smoother in “smooth mode” (by pressing 3 in Maya while selecting a 3D object). So, I’m a noob in Blender. Plus, I was trying to get the curves right on the far right of the road. Here’s some reference images I’m using:
I did increase the size of the grate for texture purposes. Maybe I shouldn’t do that. You are right as there are some faces on objects that should be removed cause they’re hidden. I thought I’ve gotten all of them. If I decide to make changes in Blender, I’ll have to remake the collisions again (cause the program hates the Maya made ones for some reason). I’m going to fiddle with it in Blender first, then put the final product here.
EDIT:
I’ll finish tomorrow in Blender and see how it looks in Unreal Engine. I’ll let you know the results.
Im sure you can simplify in Maya just as easily as you can in blender… that’s basically all that the mesh needs.
The grate should probably be a separe mesh (so it can occlude) rather than have a different texel density.
Also, don’t feel bad. You are lucky you had any sort of education at all. Teachers don’t teach you how to make a game - or what is best for performance.
You have to pay extra for that 
That, and what I had learned is long since outdated. I’ve discovered UDIMS a year ago, and we weren’t taught that at all. Thanks for the encouragement 
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I figured out how to get the colored grid. Youtubed it.
Fantastic 
Yea, MostHost_LA was right. It was the topography that caused the issue. So now I’m redoing it, at least for peace of mind. Then I should do that for my other things as that could be the reason for the “smoothing” errors. Whish me luck 
I’ve been working on it for almost the whole day now. Here is the progress so far:
Here it is with the UV checkerboard texture:
Looks much better compared to before. Though I had to look up a few Youtube videos about topography for a quick tutorial. I’m also thinking of straighting some of the concrete boarder UVs.
Much better
Thanks. I redid that three times before I gotten that. The concrete boarders are a struggling point now. I’m not sure where to begin, except for straightening the UVs.
I mean, the UV for it doesn’t need to be continuous - you can easily break it up into parts that are just straight. So long as you make sure that the start and end are both at the edge of the properly tiling texture space or that you utilize a tiling texture within the texture you use for the material, you’d never be able to spot the seam…
Okay, I’ve changed all of my 3D objects to static, instead of movable. Then built the lighting on Preview. It was then that I’ve realized that the horizontal lines show up when the road object is “movable”, not “static”. Here’s the object as “movable”:
And here’s the same object as “static”:
So, it looks like that was the issue. Though I’m still going to fix the topography to be on the safe side, as I don’t want to be surprised if the textures turned out warped.
I do wonder if the lightmap UV is at fault for the lines - or if the lines are simoly a result of the engine being the engine. Try to lower/increase contact shadows and see if the lines go away - or the shadow bias.
If they do not, then you could try to output a custom texture to the lightmap UV to check what it does within the engine…
