Better materials for SuperTuxKart and Substance Painter

Better materials for SuperTuxKart and Substance Painter

Postby samuncle » 18 Jul 2017, 22:10

Hi everyone :D

IT has been a few days now and I'm busy with the release of SuperTuxKart.
However, I want to present you some interesting tests I did especially to try to improve the quality of assets in our game for the future releases (not this one but the ones after)

Current situation:
1) SuperTuxKart as a lot of assets that reuse the same textures again and again
2) This brings down the general quality of the game and make everything looks more or less the same
3) It's hard to create materials and it takes time to do all textures (gloss map, emissive, etc) so they are often simply not done
4) The result in blender doesn't look like in SuperTuxKart

The current pipeline to create an object for SuperTuxKart is:
1) Model the object
2) Create the diffuse texture, attempt to replicate the look of STK's rendering engine in blender
3) Create the normal map and the gloss map. If you modify the diffuse then start all over again
4) Check ingame the result and tweak again and again until you are happy with the result.

Proposal:
I started to use Substance Painter 2.
It's a multiplatform software (that runs on Mac OSX, Linux and Windows) It allows you to import your assets (it can even read blend files although I didn't tried that yet).
Substance Painter helps you to paint and create textures for your assets. It will automatically generate Normal Map, Metal map and Albedo map (more on that later) based on your parameters.

Now if you use Substance, the pipeline would be like this:
1) Model and unwrap the object in blender
2) Paint your materials in Substance (there are even automated preset like add dirt, or rust)
3) Export the png textures, load in SuperTuxKart and DONE

That would simplify a lot the process of creation, allows to have more varied materials and object instead of reusing always the same textures.
Here is an example of an object from SuperTuxKart with a material created in Substance:
trial.jpg


FAQ:
It sounds cool but what kind of changes does this requires in SuperTuxKart ?
--
Currently Substance uses PBR with Metalness, Albedo and Normal map. The good news is, our render engine already uses a kind of PBR but not fully deployed yet, so a minor modification in the shader would allow us to get the same look as in Substance. It would be important since it allows artist to get immediate feedback and know more or less how the object will look in game.
Using PBR fully would also make us automatically compatible with any software using those render shader, not only substance but also Eevee, the new blender render engine

Since Substance is a proprietary software. Does it means we have to support a special format?
--
Not at all, in fact Substance will export all texture with the PNG format directly readable by SuperTuxKart. All the UV are done in blender and models are fully compatible. It doesn't prevent other people to use/share/adapt assets.

What if somebody wanna create assets for SuperTuxKart does it means they have to buy Substance?
--
Not at all, Substance is only used to speed up the process of painting texture. Nothing prevents you to paint vertex directly in blender and export the textures for SuperTuxKart. In fact by adapting SuperTuxKart to the PBR pipeline we would ensure maximum compatibility between different rendering engine.
It's a bit like choosing Gimp or Photoshop to create textures. You can even use paint if you want, at the end the result is the same, a PNG image loaded by SuperTuxKart.

Does it means that we have to redo all assets to be compatible with the new PBR system? Isn't this a bit overkill ?
--
Not at all, I think first we have to create a separate shader that will be used for objects using the new system. Older objects will continue to be rendered with the current shaders. In the end as we update the game, more and more objects will use the new shader system. It ensure backward compatibility with older assets and a smooth transition.
As I explained, STK already uses a kind of PBR, the transition is already more or less in progress

Can't we use the old Diffuse, Gloss and Normal map?
--
Those can be used but they have limitation (like a proper metal look with colored reflection). It's better to do the transition and update progressively the game.

So I hope I answered the majority of your questions. Of course if you have more questions feel free to ask :)
Sam
Image
User avatar
samuncle
STK Moderator
 
Posts: 736
Joined: 16 Mar 2010, 21:28

Re: Better materials for SuperTuxKart and Substance Painter

Postby samuncle » 19 Jul 2017, 21:14

After a few tests here is the result with an existing SuperTuxKart's object

details.jpg


I included the generated textures if you wanna try yourself. It's standard PNG textures:
https://samuncle.net/cloud/index.php/s/WLoFLR1Qg4IVt5q

In order to use this in SuperTuxKart we need a shader that takes as input the: Albedo Map, Rough Map, Normal Map, Metal Map
I will check with developers what would be the best approach for this
Image
User avatar
samuncle
STK Moderator
 
Posts: 736
Joined: 16 Mar 2010, 21:28

Re: Better materials for SuperTuxKart and Substance Painter

Postby farrer » 19 Jul 2017, 21:55

It does look very good, but just to make sure, the created textures on Substance Painter could be licensed in the way the owner wants?

I ask that because Substance Painter uses predefined materials, created from "scan-based Substance textures and grunge maps" from which I couldn't find any information about their licenses.

It's just to make sure that STK could license the created textures under CC/CC-BY/CC-BY-SA and avoid any future problems if it couldn't. The application, BTW, seems very good and AFAIK we miss something similar in the FLOSS world, besides Blender's painting mode.
User avatar
farrer
 
Posts: 64
Joined: 24 Feb 2014, 21:00

Re: Better materials for SuperTuxKart and Substance Painter

Postby samuncle » 20 Jul 2017, 10:20

I wrote to algorithmic and here is the answer:

My question:
If I use the content of substance share to create a set of textures for my asset. Can I release those textures under Creative Common CC-BY-SA 3.0, in my game, if I credit the author?

For us the most important is the ability to redistribute the end result in our game (the png generated by substance)

Thanks


The answer
Hi,

If you use the textures and modify them / use them to create another texture, then it's fine


Also the materials on substance share are under Creative Common
https://www.allegorithmic.com/legal/substance-share
Image
User avatar
samuncle
STK Moderator
 
Posts: 736
Joined: 16 Mar 2010, 21:28

Re: Better materials for SuperTuxKart and Substance Painter

Postby farrer » 20 Jul 2017, 12:35

That's good news!

Keep up the fantastic work you do on STK, samuncle! And thanks for taking time to clarify that.
User avatar
farrer
 
Posts: 64
Joined: 24 Feb 2014, 21:00

Re: Better materials for SuperTuxKart and Substance Painter

Postby QwertyChouskie » 20 Jul 2017, 20:16

Specifically:

1.2
In addition any Asset that you download from Substance Share that has been developed by Allegorithmic or that has been made available by third-parties ("Providers") that are not affiliated with Allegorithmic, will be subject to Allegorithmic’s standard Substance Share End User License Agreement ("Allegorithmic-EULA"), which is Creative Common's "Attribution 4.0 International" (please refer to http://creativecommons.org/licenses/by/4.0/), is copied in Appendix 1 to these Terms, and which you must accept as an integrated part of these Terms by checking the box indicating your acceptance of these Terms when you are register as a user of Substance Share. Certain Assets may be governed by a Provider end user license agreement.
User avatar
QwertyChouskie
 
Posts: 101
Joined: 29 Jun 2016, 14:57

Re: Better materials for SuperTuxKart and Substance Painter

Postby samuncle » 20 Jul 2017, 21:32

Hi, I'm sorry I didn't included the 3D object for you to test

Here is a new zip with everything included
https://samuncle.net/cloud/index.php/s/YEtb2mFnAqaCN7r
Image
User avatar
samuncle
STK Moderator
 
Posts: 736
Joined: 16 Mar 2010, 21:28

Who is online

Users browsing this forum: No registered users and 1 guest

cron