Weird "Edge"-Shadows on FBX Import

[C_S]

Hi,
I downloaded a free to use FBX of a low-poly ship and importet in UE5. Here I noticed, that the Pivot Point / Origin is a bit off. I just wanted to change this, so I imported the FBX in Blender.

And here is the Problem:

Left side is the Blender reimport (without any change! Just exported) in UE5 and right side is the original.

The reimported Model has some weird Edge-Shadowing. I really don’t know, how to get rid of that.
It is just a low-poly Mesh with simple Material on it. And the creator market some edges as “sharp”, but marking Edges as sharp (or not) doesn’t change the outcome.

I would really appreciate some help here, thanks!

[bOBaN]

if you just want to move pivot point you can do it directly in unreal (and do some modelling too!)

The shadowing issue you are getting… I think this might be related to how you actually export from Blender and import back to unreal. maybe something related to tangent space… Or it might be related to triangulation… or sth else… hard to tell at first glance

[C_S]

Hi, thanks for your answer, but I saw this video and as mentioned in the comments. It is not really doing the trick because the base mesh is not changed.

And it is more the Blender Problem, I wanted to solve, than the UE-Pivot problem. In the meantime, I noticed, that maybe it is really the fbx file. I imported the original file as *.gltf (which is also in the package) an there is no edge-glitch…

[bOBaN]

You can try using sent 2 unreal. I basically never import stuff via fbx (I know people do) as there are too many variables when exporting and importing via fbx. I either use the official Epic plugin or this one.

[C_S]

I am using send to Unreal form Epic already. Thanks for your replys!

I think there is just a problem with the fbx. I found sth. in the web, that it may is a problem with a Maya FBX.

[FedPete]

• Check your face normals!
• Your model has a lot of triangles, created around the mast, and floor merge. Better to have a ship body based on a mirror modifier (later applies for fbx export) and a mast. Not joining them.

[bOBaN]

@FedPete

Your model has a lot of triangles, created around the mast, and floor merge.

I’ve seen this many, many times… This is typical view after triangulation of models with none-quad topology. It’s bad topology but not necessary useless for games items that don’t need to animate/deform. Orignal author did normals correctly, but some of it wasn’t caught on by Blender.

Now that I think about it - maybe simple auto smoothing would fix the issue?

The angle might need adjustment ofc.

[C_S]

Hi, I checked normals → after import I had to “recalculate outside” because normals were randomly flippend at some Faces. After this, the mentioned problem occured.

[C_S]

Tryed it also, did not work

[FedPete]

When you have flat faces, like hard surface, don’t use Blender object smoothing.

[NP5]

Try shading it all flat. Then in edit mode select the only curved bits the masts and shade them smooth.

Some of those marked sharp edges look crazy to me diagonals across flat planes. I do not believe you need any of them, but experimentation would possibly decide that.

[bOBaN]

Redoing normals (or making some surfaces flat shading) is probably a way to go. You might look into weighted normal modifier. I think maya might use custom normals / normal groups which might not come through to blender. One way is to find those custom normals some smoothing goups in object properties and remove them… and then fix it ‘blender way’ (either using NP5’s method or weighted normals or auto smoothing or some other method).

You said you downloaded it from somewhere and it’s free. Can you link the model? I could check it out.

[C_S]

Hi, I have to try later, thanks!

Here is the link: Kenney • Pirate Kit

[bOBaN]

Thanks! I also will get to it a bit later (I treat it as useful exercise in working with models created in other 3d software ).

[bOBaN]

I had to convert fbx ascii format to binary one using this tool…

And there are no issues in blender (I use shiny matcap for easier spotting lighting issues):

So I moved it to center and exporter to ue4. Exported with default options (without using any plugins this time)… and I’ve put it into default map:

No lighting issues here as well… even if I make the light 50x brighter and look at various angles:

[C_S]

Ah ok, you used the audodesk converter! Maybe the ASCII-FBX → UE → Blender workflow is the Problem!

[NP5]

So is FBX not all the same?
There are different types?
How would anyone know?

One tends to assume file types are standard. Or they call it a new name.

[bOBaN]

@NP5

One tends to assume file types are standard. Or they call it a new name.

Yeah… but fbx is not ‘standard’… it’s file format developed by autodesk (or rather a company they bought? I don’t remeber now) and I bet they changed it many times… and other companies had their own variants… the convertor (which is from 2013) list the following variants:

Plus there is binary and ascii versions…

But even if that was not fbx issue… it has many options… like smoothing groups for normals… All of those options need to be selected correctly and the same when exporting and importing based on your model…