Hi all! Currently I’ve been importing simple Blender models into UE4 to see how they work. However, after building the lighting after importing the FBX models, something weird happens. Take a look at the weird line/bleeds here: http://i.imgur.com/q7WLDQO.jpg and http://i.imgur.com/UhEBogV.jpg
Why is the lighting messed up? Any info would be great, thanks!
#Calculate Normals
When you import the mesh, select calculate normals
Delete asset and reimport as needed.
Make sure to check this setting every time you import a static mesh!
Rama
The problem still occurs…
Use 2013’s FBX instead 2014, and don’t forget to creat a second UVSet with non overlapped Faces in your UV Layout.
This looks like issues with your lightmaps. I haven’t done any custom content in UE4 yet, but UE3 required you to create a second UV channel to store baked lighting information (ie lightmaps), and each UV ‘island’ required some padding space around it. Do you have lightmap UVs on your object?
I do. I created an extra UV in Blender for it
I’m using 2013 and isn’t the second UV supposed to hold the Lightmap?
Did you duplicate your existing UVs?
Lightmaps require all uvs to be unique (non-overlapping). This is critical to get the lighting looking correct. You may also need to open the mesh in the Static Mesh viewer and explicitly tell it to use channel 1 (ie the second channel) for the lightmap UVs.
Would you need to duplicate the primary UV in order to create a Lightmap UV?
It doesn’t matter if you duplicate them or not, the key thing is whether the UVs are overlapping. If your primary UV set has overlapping UVs and you duplicated them for the secondary set, you’ll need to re-lay out the secondary set so none of them overlap. If you didn’t duplicate for the second set, you’ll still need to ensure they don’t overlap. UE3 had ‘Generate Unique UVs’ in the Static Mesh Editor that could actually handle this process for you and set up the correct UV map into the secondary or other specified channel, so maybe look for a similar option in the UE4 equivalent?
You just need to make a UV layout with no overlapping faces.
No, by the way your first UVset can be overlapped,but you need to tell the engine to use the non overlapped UV for lightmap purpose.Can you show us how you open the UVs?
Be sure your normal are right as well,sometimes when you modeling half of object and duplicate/Mirror then,is could cause negative normals.I’m a Maya user,in maya you can use Set Normals to Face.
In Blender, I have a UV map of my model with no overlaps or anything. I then have a second UV map that is blank, which I created for the lightmap
Right, so if your primary UVs don’t overlap you can just duplicate them into the second channel, re export and then reimport the asset. You may still need to tell the engine to use channel 1 (ie second channel though, so check in the static mesh editor.
The second map can’t be blank,it need to have a Layout with non overlapped UVs
In this case ,if your first map have non overlapped UVs,just copy this to your second UVSet
Turns out there is a generate Unique UV in the UE4 editor. How would I use this?
I don’t have your current build to hand, so things may be different in my version. UE3/UDK had this option though, so for a quick fix I’d try googling for a tutorial on how to use it in the UDK and seeing if there’s enough similarity to roll with it.
Sounds good! But did the UDK version just generate your UV maps for you?
I don’t think you can do that in blender. Is it possible to do that in UE4?
Yes,but always prefer to create your own.You’ll have more control over it
