Aero L-159 ALCA

[MIG29pilot]

Now you're going really offtopic

Sorry.
Thanks!

[MIG29pilot]

Never has crashing been so fun.

[pjedvaj]

I've decided to give this aircraft some love. I'm currently working on a single seat attack version of ALCA.

Model renders:





First screenshot:

[pjedvaj]

Package is based on the original L-159 and in this stage it has most of it's functionality (disintegration still isn't enabled) but it is repacked as ALCA.



GitHub repository for the ALCA project: https://github.com/pjedvaj/ALCA

ToDo (short term):

1. UV mapping of external model
2. Textures (liveries)
3. Animations of external model

ToDo (long term):

1. Cockpit model
2. Instruments
3. Weapon system
4. New weapon models and textures

[pjedvaj]

Update on progress;

ToDo (short term):

1. UV mapping of external model - checked
2. Textures (liveries) >> to be done
3. Animations of external model - checked

It came back to me why I hate working with the AC model file format.

[legoboyvdlp]

Looks good

[pjedvaj]

It should look very nice when I finish it; I've played with FlightGear's ALS shaders and I'll be using Substance Painter to paint it and export PBR maps.

[pjedvaj]

It's really hard to control reflectivity with texture maps in ALS shader;



I'm getting much better results by disabling it.



Does anyone have any clues (yes I've read the manual and played around)?

[legoboyvdlp]

What you want is a texture that controls reflectivity with the alpha channel.

It goes in texture slot n4:

Code: Select all

<texture n="4">         
  <image>Aircraft/Generic/Effects/ReflectMaps/reflectmap.png</image>
  <filter>linear-mipmap-linear</filter>
  <wrap-s>clamp</wrap-s>
  <wrap-t>clamp</wrap-t>
  <internal-format>normalized</internal-format>
</texture>

It also must be enabled:

Code: Select all

<reflect-map-enabled type="int">1</reflect-map-enabled>

It seems that the alpha channel (0 - 1) is multiplied by the material specularity to give the final reflectivity.

The bare metal of your texture should have maximum alpha I think, while the paint should be a lower value (0.2?)

Also remember that reflections and specularity are different things although they seem to work similarly. Specularity is the reflection of light sources while reflectivity is basically just reflecting a cubemap.

This: is specularity



while this is reflectivity:



A mix of high specularity and weak reflections seems to work well especially for airliners but for fighters it might be different.


By the way, that looks really good -- nice work!

[pjedvaj]

Thanks for a speedy reply and help.

At least I got the code right (now is disabled).

Code: Select all

<!-- Reflection -->

      <reflection-enabled type="int">1</reflection-enabled>
      <reflection-type type="int">2</reflection-type>
      <reflection-dynamic type="int">1</reflection-dynamic>
      <reflection-fresnel type="float">0.01</reflection-fresnel>
      <reflection-rainbow type="float">0.2</reflection-rainbow>
      <reflection-noise type="float">0.01</reflection-noise>
      <reflection-correction type="float"><use>/sim/rendering/refl_correction</use></reflection-correction>
      
      <!--

      <reflect-map-enabled type="int">1</reflect-map-enabled>

      <texture n="4">
         <image>Aircraft/ALCA/Models/Liveries/Metallic.png</image>
         <filter>linear-mipmap-linear</filter>
         <wrap-s>clamp</wrap-s>
         <wrap-t>clamp</wrap-t>
         <internal-format>normalized</internal-format>
      </texture>

      <texture n="5">
         <type>cubemap</type>
         <images>
            <positive-x>Aircraft/Generic/Effects/CubeMaps/fair-sky/fair-sky_nx.png</positive-x>
            <negative-x>Aircraft/Generic/Effects/CubeMaps/fair-sky/fair-sky_px.png</negative-x>
            <positive-y>Aircraft/Generic/Effects/CubeMaps/fair-sky/fair-sky_ny.png</positive-y>
            <negative-y>Aircraft/Generic/Effects/CubeMaps/fair-sky/fair-sky_py.png</negative-y>
            <positive-z>Aircraft/Generic/Effects/CubeMaps/fair-sky/fair-sky_nz.png</positive-z>
            <negative-z>Aircraft/Generic/Effects/CubeMaps/fair-sky/fair-sky_pz.png</negative-z>
         </images>
      </texture> -->


I'm not going for glossiness or specularity, I need reflectivity shader to render Metal map exported from Substance Painter.

Didn't know about Alpha channel multiplication, that should be it. I'll try to play with it.

[pjedvaj]

Thanks again, you saved the day. Alpha did the trick, fully transparent is non-metal, and opaque is rendering as metal.



I'm still getting issues from my normal map interfering with reflectivity (darker texture and UV seam lines). I'll paint it manually anyway;

[legoboyvdlp]

Looks great! I don't see any normal map at all though; I hope that didn't break it?


Also, is this going to be your final livery? I don't think you can change this runtime.

[pjedvaj]

It's just an original one exported from Substance Painter, I'm drawing fuselage seams and rivets by hand in vector to be used as normal map.
Don't worry, it's also just a shader test livery.

I'm planning to paint at least 4 liveries: CZAF, IQAF and Draken included.

[legoboyvdlp]

In that case you would need to redo the reflectivity map (I'm sure you realized that). An all over low-value (whatever you used for the red paint) should work except for parts that are bare metal, like the gears or whatever else

[pjedvaj]

Hope everything will go smoothly, for now I'm getting good results. This is first time I've used Substance Painter and it's a pleasure to work with.