UVs, Lightmaps and headache

anonymous_user_d41a5329 · February 9, 2015, 7:53pm

Well hello guys. I’ve been trying to solve this problem for a week now and I’m slowly loosing my mind D:

The thing is that I have a model of a chair with a high number of polys (20k) and I HAVE NO IDEA on how to create a good lightmap for UE4. I’m a total beginner in 3D modeling. I use 3DS, I unwraped the UV in a second channel, and I tried every single button I could. Many times I got no overlaping settings but its so shrunk that at rendering time in UE4 it shows me black and gray boxes all over the mesh.

Here’s my model:

And here is the default UV:

And I’ve ended up up with something like this (more organized, but not too much diferent)

The thing is UE doesn’t like that. I’ve seen all kind of tutorials, tips, guides or whatever, but how in the world am I supposed to fit all those lines into a 16x16 square? I’m aware of increasing lightmap size in UE4, but in 3DS I’ve found no info regarding increasing UV size. So what can I do? I even have a 400k polys mesh, so I don’t think it’s impossible :B

Thanks in advance!
PD: Sorry for my bad english, it’s too late and I can’t even think straight :B

darthviper107 · February 9, 2015, 8:40pm

While the engine can handle models with that poly count, it would be much better to work with a model designed to be used in games/realtime. The poly count just isn’t necessary and you’re going to have issues working with it as you can see.

Still, as far as UV mapping goes, you can unwrap it, but you have to do it the right way, no automatic method will give you as good of results as doing it by hand. You may need to do some general UV unwrapping tutorials.

anonymous_user_d41a5329 · February 9, 2015, 9:33pm

Yes, I supposed so, so I will change my question so I can know, what is the recomendable maximum triangle count in UE4?

darthviper107 · February 9, 2015, 10:20pm

It depends on a bunch of things, everything takes resources so you could have a higher polygon count if you have less textures, things like that, you generally try to shoot for something you think is reasonable and then do testing, if it’s too much then you make adjustments.

Steve_T · February 9, 2015, 10:25pm

would it be worth trying to make it into a skeletal mesh? That way you don’t have to worry about a lightmap.

I’m assuming this will affect shadow quality though?

anonymous_user_d41a5329 · February 10, 2015, 1:28am

I’ll try some combinations and I’ll tell you later.
Thanks you guys!

iiCON234 · February 10, 2015, 1:45pm

Yeah I had an issue similar to this and I just gave up and used it as a skeletal mesh like Steve said.

qdelpeche · February 10, 2015, 1:50pm

lol … Skeletal meshes … the saviour of all non-uv experts the world over. 8-}

Tim_Hobson · February 10, 2015, 2:15pm

If you don’t want to use lightmaps you don’t have to go as far as converting it to a skeletal mesh.

When in doubt do the following:

If you don’t want to use static lighting on your mesh just uncheck the option for “Cast Static Shadow” in the details panel.

So long as your have dynamic and/or stationary lights in your scene your object will be lit by them and not require any lightmapping.

Voodoo · February 10, 2015, 3:34pm

[QUOTE=Tim Hobson;219493]
If you don’t want to use lightmaps you don’t have to go as far as converting it to a skeletal mesh.

When in doubt do the following:

&stc=1

^^^ Classic/Awesome hahahaha!! Note to self thx for the tip Tim will remember this for my project! OP looked very angry with that smiley

Tim_Hobson · February 10, 2015, 6:49pm

UVs and Lightmaps can be very frustrating at times! I can’t say I didn’t struggle with them at first. Heck, there are even times now where I over think some things and just have to go back to the drawing board and do it over or think more clearly about what I want my results to be. There are a lot of options in UE4 that may not be something obvious at first. I’ve fallen into that trap as well. It happens, I learn, and I pass it on to others as I see everyone else doing which is just awesome!

qdelpeche · February 11, 2015, 7:09am

ROFLMAO … that’s it … I am getting a T-Shirt printed. 8-}

anonymous_user_7af3b797 · February 11, 2015, 8:36am

@Tim Hobson
Hi, thanks for the tip. Will save lives.
I have to say, that lightmaps are definitely the weakest point in UE4.
I’m actually finishing project in UDK not UE4, but non-the-less I will say what I’m experiencing.

I have a box - just regular six sided box. Unwrapped meticulously, uvs spaced out on UV grid so they are fair distance from each other. What else can I do? Building lighting, production quality, shades are bleeding. Unbelievable.
No, No, as I may look trough my fingers on other’s UE4/UDK’s shortcomings, I genuinely believe that lightmaps are from stone age. I do hate them.

Other than that happy, no worries