UDK: Lightmap UV Layout Techniques & How to Create Second UV Channel in Maya Part 2/4 [Tutorial #19]

Blog Post: www.worldofleveldesign.com/cat...
In the first part of the tutorial ( • UDK: Lightmap Basics -... ) we covered all the basics and important principles for UDK lightmaps. Now let's go deeper into practical examples and techniques.
The following tutorial we will cover the following:
-How to create a second lightmap UV channel in Maya
-Lightmap layout techniques - padding, resolution
-How to match UV layout grid resolution to UDK lightmap resolution

[@gorkemuzun7451]

8 years later still very important video.

[@frostypawsgaming1338]

4 years later still very important video.

[@EyefyourGf]

I respect his dedication and putting tutorials,but some things he is doing wrong here,so il just write here in hope it will help some people,
You need to substract 1+1 to all your lightmaps grids that you use in your UV editors.
32x32 Lightmap ? Grid has to be 30x30
64x64 >> 62
128x128>>126
256x256>>254
etc... of course...
There is a hidden advanced setting on by default in UDK that say to Lightmass to use 1 pixel border for filtering purpose, so that's 2 pixel on ANY lightmap size. It's still ON in UE4,and that's why we are substracting 1+1
Values for the grid size,Maya or Max it doesn't matter
1/30 : 0.033333
1/62 : 0.0161290322
1/126 : 0.00793650
1/254 : 0.003937007874
1/510 : 0.0019607843172
1/1022 : 0.0009765625
I tested this myself,and it works flawlessly,i always had issues with modular walls,you could always see a seams across modular pieces,not anymore tho,and again 1/32,1/64 etc is simply not accurate.
link to article where you can read about this,in more detail www.reddit.com/r/UE4Devs/comments/246whl/the_most_important_thing_about_lightmaps/

[@kasonclark1459]

Pro tip : you can watch movies at Flixzone. Been using it for watching a lot of movies these days.

[@jaidenkalel1312]

@Kason Clark yup, have been watching on flixzone} for since december myself :)

[@wesleykelvin4468]

@Kason Clark definitely, been watching on Flixzone} for since november myself :)

[@saeedzamani1503]

Couldn't be more clear to understand.
Thank you so much

[@Nastea315]

Dude, thank you so much for your thorough explanation. This is exactly the lesson I needed to understand and use in my work. Awesome job, hope you keep making contents!

[@dankjeenyus]

yes ! I'm so excited, your videos are the best I've seen covering light maps in maya and UDK, thanks again soo much, I'll be patiently awaiting parts 3 and 4 :)

[@andrejim3814]

6 years later and still useful , thanks.

[@geLokie]

Very informational video, thank you very much for explaining in a way that I could understand it !

[@frostypawsgaming1338]

This was a great tutorial. Good Job!!

[@WorldofLevelDesign]

Thanks!
parts 3 and 4 are coming within this week

[@RAININGBLOOD78]

Great tutorial, thank you so much.

[@chillingoutt]

Amazing Tutorial! Thanks :-)

[@KLICKSTOP]

Great tutorial!

[@bandoli66]

Great tutorial. Thanks!

[@slamdaddy69420]

Great video, thanks

[@WorldofLevelDesign]

thanks,
In the tutorial I used Maya and UDK (Unreal Development Kit).

[@Benjam901]

:') such a hero quality tutorial!

[@danaiikatsulajm9878]

great video

[@DEADMAN66613]

Sweet videos! Thanks a lot, they really help. I do have one question though: I'm having issues setting up a 2nd UV set for light mapping an object that isn't necessarily a box. (eg a pole, with a rounded knob on the top.) Maybe you could explain, or make another vid on laying out a 2nd UV set for more complex / organic objects? Would be very much appreciated! :D

[@Wvk5zc]

Excellent tutorial, thanks alot! One question though, how about for objects that are more curvy eg. cylinder? Whats the best way to uvmap it?

[@iranaester8156]

Thanks a lot)

[@1983Johnny123]

Thanks for the tutorials, they are great.
But how can I measure and modify the pixels in UV texture editor in 3ds max?
Thanks again!

[@DavidBoura]

What do you think about the actual 4.5 Preview automatic lightmap UV? I'm just a beginner trying to know if it is still better to create them by hand?
Anyway, your vids here are excellent whatever the engine now in 2014, very well done & thank you!

[@Haruyuki_Art]

thank youuuu

[@TichingLAB]

Hi!!!! How to avoid or control the dark shadows on the bottom?
thanks!!!

[@i_amthearteest4129]

Perfect

[@robochrish]

Fantastic tutorial! Out of interest, why don't you set the grid up on the UVW editor like this- Length and width: 64 - Grid lines every:1 - unit Subdivisions:1.
Surely this will give the same results and will save doing calculations?

[@goribigon]

thanks

[@dankjeenyus]

Awsome videos ! Where are parts 3 and 4 ?

[@ljiljankocurcic8893]

This is all good for getting started, but what about some more complicated meshes, like large mech robot with multiple uv channels on? After combining objects in 3d program, laying out LM uv manually would be a nightmare. But still, automatic mapping doesn't provide any better results neither...

[@WorldofLevelDesign]

Is your robot a character with a skeletal mesh? Dynamic objects calculate lighting in real-time and don't need lightmaps. For more complex static objects you can duplicate the UV texture channel and use that as a starting point for a lightmap.

[@FAHDSAJER]

now i see why my shadows been wrong but dude i work with 3d max and this is frist time in i know there is light map !! i work with 3d 8 years teach my self wuta west -______- saudia arabia ^_--

[@arashi8876]

Thanks for this amazing Tutorial ♥ !
What's the best Resolution for LightMap UVs, 32 or 64? (For UE4)

[@WorldofLevelDesign]

That depends on the size of the object and how much of accurate light/shadow information you need. I go low when the object is small and far away. I go higher when it is an important object and larger, near the player.
Lower resolution will produce less accuracy but also lower lightmap size texture storage, higher resolution will produce better results but also at a higher lightmap texture storage.

[@arashi8876]

@@WorldofLevelDesign Thank you very much again ♥, This is really helpful !

[@DJacKnifeAlpha]

Does this tutorial apply to UE4 as well?

[@WorldofLevelDesign]

+JackKnifeAlpha Yes it does.

[@AlphaChino1925]

what's the color of the lightmap? is it pure black PNG like in Blender lightmaps?

[@WorldofLevelDesign]

It is just a second UV map that will store lightmap information. There is not color to it until you bake lighting and that lighting information is then stored into a texture and will be different from object to object.

[@AlphaChino1925]

@@WorldofLevelDesign so it's pure black when you have not bake the lighting information? I'm just asking coz some of my client ask for a lightmap that will be exported as PNG image... I used to create lightmaps and bake lighting in UE4, but haven't experienced exporting a 'blank' lightmap as PNG...

[@WorldofLevelDesign]

There are 2 things here:
1. Wireframe of the 2nd UV channel, your lightmap channel
2. Actual baked lightmaps from the game engine.
You can export the 2nd UV channel that is going to be used for lightmaps as a regular file (PNG, JPG, TGA etc). This will be a simple wireframe screenshot just like a texture wireframe. If its blank, that means there are no UVs created for that channel.
Inside a game engine, after you bake lights the engine will generate a lightmap texture. These textures can also be exported but they will contain light/shadow information of your scene and objects within the scene. Although these textures are usually packed into large texture files that contain dozens or even hundreds of objects and their light/shadow information.

[@AlphaChino1925]

@@WorldofLevelDesign Thank you for the info..

[@lucasatum]

where i donate??? :b

[@Horrificdoom]

Unfortunately it works completely different in UE4 or UE5. Snapping to grid has no point in 3d Maya and you will have infinite shadow seams between modular assets, such as walls or floors. In opposite you don't need to be woried about some organic or spherical meshes in which lightmap is like one strange shell. Lighting on such meshes will be excellent. So on this time i don't understand how to work with such "static lighting" and what reason for existing for it. Yes it works fine in second way, but ugly in first. The only reason is to merge all assets with seams and make one continuous shell. Cause on every edge of every separated shell you'll have shadow seam 100%
I don't understand why Unreal puts those seams between modular objects. Even if they are crossing each other, so this is not hole between them.

[@DigitalLoom]

thats to much man!! seems like more problem solving and sowing then actually being an artist ..that really ruins the fun of design for me!! sighh.it just should not be that hard what is my mesh has like 100 subdivisions on it that means id have to manually position a thousand faces for a building!! there has to be another way!!