How do I make a mesh in Blender be ready for UE4?

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Any good tutorials about how to create a mesh in blender and have it ready for materials in UE4?

My first try at this was to create a sphere i Blender. But when I got it into UE4 and applied the example grass material, the sphere looked green but without any textures. Simply applying the grass material to a brush sphere in UE4 looks as it should with textures and all.

I’m suspecting that I have to make the sphere ready in Blender with UV, etc before exporting. But then again, I don’t see why I would apply materials in Blender as I only want to use materials created in UE4.

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  1. First of all you have to unwrap your models so that the texture shows up correctly -> Edit Mode - U - Unwrap
  2. get the right scale: ?v=JR7CAHxGBcY
  3. Create a 2nd uv channel (not necessary for simple models)
  4. probably also add a collision (you can also do that in the UE4):
  5. Export and import it
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The above are good resources. Came across them naturally while googling.

I’ve played around all day today with making and prepping simple (but more than just cube) static meshes in Blender. Manually uv unwrapping. And importing into UE4.

Questions:

  • Does UE4 need the lightmap to be in UV channel 2? Or does the “light index” setting in the SM Editor determine which channel is the lightmap?

  • What is the first UV channel used for? If I am following correctly, I’d say it’s used for the texture map? Is this correct? What if I don’t have a texture. Where do I put my lightmap, then?

  • “(not necessary for simple models)” where is the line drawn on this?

  • Why 2 UV maps? What additional information does the second UV map have? And, does it help at all to manually uv-unwrap for the 2nd-map/lightmap? Or should it intentionally be done using Smart UV, even if that doesn’t work as well for natural objects (as some have said across the net)?

  • If manual uv-unwrapping is better, are there any good resources on this? Tips and tricks for how to do this to best be used in games? I’ve not had much luck finding anything like this. All I’ve picked up from reading is “less islands is better” and “align to the pixels” (but I don’t know how to do this yet).

One last thought/discovery/experiment:

I did a test. I used a blank project, and just added in my static mesh and threw together a basic red-plastic material. This works okay, but I do see small seam/hard-shadow lines. I spent a while lowering my island count in my uv map and it helped, but some are still there.

I put my same model into the Realist Rendering/Lighting demo. And I used one of the demo’s materials (porcelain and then shelf-wood). In both cases my model looked great! No weird shadows or anything. It fit right into the demo.

This, to me, seems to suggest that one may have a better lightmap than they think, but if you don’t ALSO use good lighting and good materials then you may get little glitches – and you may think it’s your lightmap. For example: did I need to spend an hour or whatever playing with my uv unwrapping? Maybe. OR maybe I should have played around with lighting and materials more in my blank project. I actually hope it’s the latter, because I don’t see how my simple static mesh chair uvmap could get any better.

Am I missing something, or is this on the right track?

I learn by trial and error. And I have no problem going back and forth between Blender and UE4 all day. But I like to know where the issue is. Is it the map? is it the lighting? the materials? Debugging tips are very welcome here. (Note: I totally understand that gamedev is complex, and likely there are problems in many places. But any tips is better than nothing ;D )

Context: I am essentially a 3d-modeling/asset-creating noob. I post all this because maybe somebody will share some tips, and maybe these concerns will help other noobs feel less alone.

Sorry for wall of text. Thanks for your time.

edit: i’ve also lurked the forums for answer. but i can see even today people are asking similar questions. so links to good forum answers are also gladly welcome. thanks.

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I just thought I’d add some info here. For posterity and whatnot.

I’ve been using Blender 2.70a.
And FYI, I am learning this as I go, so everything is my opinion/experience.

From what I’ve done, the UV channels are base 0, so they go 0,1,2. And the second UV channel (usually UV 01 in Blender) is considered the default light map on import. You can change this inside the mesh editor in UE4 (double-click the imported mesh.)

The first UV channel is for your texture map(s). From my understanding, you always want a UV map. This tells materials how they should be wrapped on your object. I am also a noob here, but I don’t know of many (any) instances where you don’t want a UV map. But in a worst-case scenario, just specify which UV map is the lightmap UV in the mesh editor.

I would say anything that is more complex than a cube. It becomes much more important the more complex your mesh. Especially when you have curves and more organic-type meshes. You can use the built-in lightmap generator in UE4, but it’s not so great for complex meshes. I made a leather chair, and the generated lightmap was terrible compared to my own lacking efforts.

Your lightmap and texture UV map usually will not be the same. With your texture map you want to minimize stretching and seams. But with a lightmap you want to think about where the light will break. To be honest, I am still working on fully understanding lightmaps, so I am a bit more fuzzy on that.

As a side note, I have found that Smart UV is servicable for something that you are just rendering, like a high poly mesh. But once you want to bake textures to a low poly mesh, you will want to maximize your texture space usage, seam placement, minimize your stretch, etc. through a custom UV map. You have so much more control when you choose your seams vs. the automatic options.

In my experience, yes, less islands is better. You also need some padding between the islands. With a texture UV you want to hide the seams as best you can. Sadly I don’t have many resources. Honestly this is one of the harder parts. Trial-and-error has been my current tutor.

In regards to your experiment, I have the same issue. A real difficult part is knowing where your mesh is fudged up. Is it the mesh geometry? Is it the baked normal map? Is it your uv unwrap? Is it your lightmap? Is it an export/import issue? If you go into troubleshooting mode just make sure to make small changes so you can pinpoint the problem.

The more complex your mesh, the more things that can go wrong.

Hopefully this was a bit helpful. And if anyone knows anything about texture UV and lightmap UV tutorials I would be most appreciative as well. Specifically, why is it so hard to get a good lightmap on a curved mesh? What are the guiding principles on lightmap UV unwraps?

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ok without reading both long posts i’ll keep it short
ALL static meshs (eg no bones) need a lightmap
you don’t need a second uvw map IF your first map has all unique uvw’s , eg no overlapping faces or islands
if on your first uvw map you have overlapping (maybe mirrored) uvw’s then you DO need a second uvw map with all faces/island having unique uvw’s.

as shown on my blender playlist

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The reason for two UV maps is because in the first texture UV map you may want to overlap UV maps to share the same UV space to get better resolution. For example if you have a building with the same facades on the front and back and the sides, instead of four UV islands, you might want to make the front and back islands exactly on top of each other and the two side islands exactly on top of each other. Now you can make the area used by each island twice as big and get better resolution on your textures. For the lightmap, you never want any overlapping UVs because it will mess up the lighting and shadows. You may also want to have different seams and different island gaps between the two UV maps.

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RE: #2,
It sounds like he’s saying ctrlA then CtrlP, right ?
When I do that I do not get the ‘margins’ UI at all, but I know what he’s referring to as I’ve seen it before, just now working here with 2.79 latest.

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Wow, way to necro a thread, my friend. You can find the margins UI in the bottom half of the toolbar (the one on the left side) of the 3D view.

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YOur comment is out of order=- necro, how funny got anymore jokes ?

I asked a pertinent question, I’m so sorry it doesn’t meet with your RIGID guidelines,did I miss something in Ue4 guidelines as to questions someone can’t ask ?

I suggest you RE-read them.

I wasn’t asking where the UI is, I was asking what commands he’s issuing–I used to be able , last year or such, to get that very margins UI to show up, but its not working–hence my question: was I not hearing the video creator correctly or has that changed ? I tried various combinations ,RE listended to video to make sure I was hearing him right ( not always easy to hear him correctly) and I was pretty sure he was saying Ctrl a and p, if that isn’t right I"d love to know, so I can get the margins UI to pop up,I looked as well, when it wasn’t coming up, to find it and I didn’t sere it. Maybe blenders UI is a bit crowded, I’ve heard its confusing but I"m more or less used to it…maybe not enough but I"ve not used it all that much recently bc the viewport is so slow for complex meshes and that remains true- ( BUT 2.8 alpha is tons better thankfully )–prob why I"m not as current on blenders UI as I could be.

I offer this bc you seem to be insinuating I’m killing this thread ,for some unknown reason only you are aware of, apparently.
Darth offered a video for help on creating lightmaps in blender and it seemed logical to ask here for a problem I was having, so that others who may use it will be similarly having problems possibly–seemed pretty clear cut. I also just now did a bing search and I"m finding nothing about ‘margins UI’ in blender–I guess its not a often searched item.

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OK GOOD, I found answer–in all fairness, OP was going rather fast prob thinking everyone knows the ‘basics’, and while I do , his ‘t’ panel was in the middle and its normally on the left side which was a little confusing—

I found: https://blender.stackexchange/qu…ce-out-islands , which clearly shows where its supposed to be ( default layout in blender anyway), ,I ‘thought’ his video showed having mouse cursor in left side, but indeed it must be on right side where the actual uv-unwrap windows is, and thing ctrl a-p and,after a bit of time it shows up…it took quite a bit of time so I thought I was still doing it wrong,the mesh isn’t that big-finally the UI showed up, so I’m all good. Thats what was going on clearly. I’m using blender 2.79 for this, which btw still has/had a very slow viewport rendering component,meaning my 230k mesh makes blender crawl here. Blender 2.8 is tons better, thankfully and appreciatively, but using 2.8 for this crashes it,we’re not there yet is all.

I still don’t get your necro comment, but given bing’s search on it , defintion shows as something ‘dead’…

Curious use don’t you think?

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Oh btw, on that note: is this ?v=UnUn4nRoh-E, method of unwrapping for export to UE4 , preferrered ( or just another way of doing it) vs the one darth referred to ?

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Yeah, most viewports in Blender have a T-panel (left side) and an N-panel (right side). The left one is the tools panel, the right one the properties panel, in case you’re interested in the terminology, since Blender can get confusing at times. And the UI for stuff like margins when packing islands can always be found in the tools panel of the 3D viewport and not, like one would expect, in the viewport where the action was performed in.

Necro-posting is when someone in a forum or mailing list writes a message in a thread where the last post is very old. Usually, when the last post is older than 4 to 6 months, continuing the thread would be considered necro-posting. You posted in a thread that is almost 4 and a half years old, hence my comment.

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I posted here, prob. bc I searched for something like How do I make a mesh in Blender be ready for UE4, and ya I noticed it was 4 yrs old

darn ,anyway :

  1. First of all you have to unwrap your models so that the texture shows up correctly -> Edit Mode - U - Unwrap
  2. get the right scale: ?v=JR7CAHxGBcY
  3. Create a 2nd uv channel (not necessary for simple models)
  4. probably also add a collision (you can also do that in the UE4):
  5. Export and import it

is why I posted here having found this thread for reasons stated herein, if there is a ‘better’ thread, more current sure I would have preferred that,but my questions arising out of using blender mandated I post here, my question was directly related to darth’s recommendations.

You are free to use useless banter all you wish but it doesn’t alter the fact , this thead had info pertinent to what I needed- end of story and i refuse to get bogged down in nonsense.

IF a forum moderator wants to force all of this since my ‘necro’ comments they are free to ( to a unique, new thread), I"ve no problem with it at all.
You chose to use unflattering, childish words to encapsulate your intent- nobody forced you.

I thought this forum was about ‘professional’ help, and you are doing nothing to further that along.

Just so everyone knows what I"m referring to, as an EX: I’ve been using ( NOT my preferred engine at all, just a curiosity in part) lumberyard forums for assistance in various engine help, and at no time did anyone, dev or moderator or engineer, veer off into insulting references to ‘old’ threads, or any other similar mentality. I"ve had wonderful, adult experience over there. Makes one think…BTW: That is in on way meant to insult you, this forum, this engine or any other similar topic, its meant to showcase how feelings can get hurt when we/some engage in insults.

Btw ty for the explantion, but it was wholly unnecessary as I"m WAY beyond that beginner stuff, for me at least–my ONLY confusion came as result of the OP ( of video) using his OWN layout, that and nothing more, plus having a hard time , being sure I was hearing him right bc of his dialect and my inability to ‘see’ the margin UI come up…I was simply, and obviously now, not placing cursor in right pane PLUS given blender 2.79 is SO slow regarding its viewport speed, further exacerbated my ability to see the margin UI in a timely fashion clearing showing I had done it right as OP intended. Thats about it :wink:

I’m done here unless I have further comments, directly related to responses on specific questions, and if further responses carry any negative ,unnecessary wording, I’ll ignore it completely and not respond from now on. I do not come here to get attacked. I do not get attacked on lumberyard forums.

That has NOTHING to do with the fact I use, and MUST continue to use, for now anyway, UE4 as engine of choice. That decision may change, ( not that anyone here cares).