Weird shadows

I’ve modelled this piece of barrier wall in 3ds Max, which I plan to bend into different shapes with bend modifier in 3ds max.

  1. Modelling (Wall and rails are to seperate objects)
  2. Unwrapped both
  3. Applied Multi-sub object material so that UV’s are seperated in Substance Painter
  4. Textured the wall in Painter
  5. Opened the wall FBX in 3ds max and made that 90 degree corner piece (with Bend modifier) and saved it as new FBX
  6. Imported to UE4

However, I’m getting weird shadows in few areas. What could it be? Did I do something wrong with the corner piece?


Here are the seperate pieces, which seem to be okay:

And I’m pretty sure there’s no shadow issues here:

From Step #4 (Substance Painter)

There’s a problem with your lightmap UVs. In the static mesh editor, click the UV button at the top-middle of the screen. Then open the “UV channel” dropdown menu to the right of that and you should see a second UV channel. That’s your lightmap UV. If it’s overlapping or badly laid out, it will cause errors like this.

UE4 generates ONE lightmap per object. When you import the fbx are you combining meshes, right? If yes, that means you are creating ONE lightmap for the entire fbx. That wasn’t clear for me for a while, but after many tests I realized how that works.
Really bad limitation, I know… why this works this way is beyond me. Most annoying thing for me is anyway lack of pivots, hierarchy and object animations…

dzodzu, when you import your fbx there is a tickbox saying “combine meshes” or something to that effect. If you untick that, it will import your FBX as a series of mesh assets in the content browser, instead of one single asset. That might actually help Latetzki too.

What you have to do is: Inside of 3ds max, select all wall pieces, put unvrap UVs modifier with 2nd channel with all wall elements selected and flatten all out in UV space. Than you can collapse the Unvrap modifier, or convert to editable poly.


Also I can see that you will have to work on colliders. Yes… another limitation of UE4. Colliders are convex only (and not even hulled)…

I know. But then you will have to create a blueprint and combine all there, and not necessarily what you want. It’s better to make bigger pieces, to not create too many draw calls. So what I usually suggest is to divide static meshes per lightmap.

Ah I see, that’s actually what I do too. Although I’ve heard some disagreement about whether it’s better to have several big pieces or many smaller pieces (for more efficient culling). But that’s a little off topic.

Yeah, just test what works best for performance. Sometimes one way can be better or sometimes another. Anyway I hope I was able to help.
And sorry for my lamenting about limitations… just switched from Unity3d not long ago and some stuff causes me headache, from the way how much more work I have to put in UE4 just to simply import one stupid model… :stuck_out_tongue:

Your lightmap UV’s are probably fine, but you need a higher lightmap resolution