Image Atlas

[TattieBoJangle]

Been thinking guys and going forward we really need something to fix

1. The image files are getting crazy in projects having D,N,R,S,E,AO maps the end game is going to be huge in size
2. Memory is going to be a thing also having all they maps yes it helps if they are all the same size but still going to be an issue.
3. Performance due to the way the Texture Arrays work we would see massive improvements if atlases where added.

So what I am asking for is this we have the ability to create atlases our self but we need skyline to be able to read the xml file that stores all the data in the atlas with their coordinates and sizes ect, this would let us convert a model that has say 6 textures times that by channels D,N,R,S,E,AO that's 36 textures down to 6 or if you only use 1 channel that's 6 textures down to 1. Below is an example the 6 images have been packed and is 1px space you can have it more

<?xml version="1.0"?>

<sprite file="testimage.bmp" name="testimage">
<frame name="1" x="1" y="1" w="1024" h="1024" />
<frame name="2" x="1026" y="1" w="1024" h="1024" />
<frame name="3" x="2051" y="1" w="1024" h="1024" />
<frame name="4" x="1" y="1026" w="1024" h="1024" />
<frame name="5" x="1026" y="1026" w="1024" h="1024" />
<frame name="6" x="2051" y="1026" w="1024" h="1024" />
</sprite>

[SpiderMack]

+1.

The main advantage of atlas is it saves draw calls because you use the same material instead of having multiple materials

But it's making the workflow longer if users need to make them in a painting software, it has extra steps most users won't do.

Instead some auto atlas tool would be the best solution.
It would generate atlas texture and a new material for set of 3D models you selected automatically.



Another tips to reduce number of images needed is to combine maps into color channels (like it's done for some 3D engines)
Most software like 3D Coat, Substance Painter and Designer have options to define your own image export format (or Skyline could make some image packer tool when you want to use separate images)
For example :
Roughness = blue channel
Metallic = red channel
AO = green channel

[epsilonion]

[SpiderMack]

[SolarPortal]

Several Valid points throughout this post:

Atlases do make an improvement only if the same texture and materials are shared between models as to reduce drawcalls as Spidermack says, but its also a very good memory optimization. However, quality can suffer because of atlases because if all your textures are 1024 or bigger and you want to atlas lots of them, then the images will get too big and cause stalls as they are uploaded / removed from the GPU.. This is where texture arrays excel in performance as you can have 40 1024's in one texture array.

As for packing, this was an idea we were initially going to add, so you provide skyline with the skyline you want and it would pack all the monochrome or single channel textures into empty spaces of diffuse, normals, spec etc...
Generating a custom atlas would be a really cool feature for skyline and would benefit the lightmapping creation process when added.. 2 birds 1 stone lol..
however, it is a lot of work...

The problem with the data is the offset UV locations which would have to be edited inside the shader to make real use of the atlas through XML as UV data is stored within the mesh data... this isnt to say its not possible though...

need to have some thoughts and an internal meeting on how to approach this... we hear your ideas, like them but need to figure out best how to integrate them and how much time it would take...