For the nolok kart, use dedicated nitro textures

[Al2Klimov]

Had kind of a shower thought:

Nolok already has special stuff such as the green gum bubble. But the nitro stream is still the regular (not to say: boring) blue. Why not to make it red - after all he's the evil guy!

Thought. Done.

Bildschirmaufnahme_20260118_230213.webm

Admittedly, there's still some blue light below the kart during nitro usage. I'm new here and have not found the necessary texture, yet. Maybe someone can give me a hint.

Speaking of textures: To run this PR, you need to set SUPERTUXKART_ASSETS_DIR= to a copy of stk-assets with the following modifications:

--- ./textures/materials.xml.orig       2026-01-18 22:54:39.556897171 +0100
+++ ./textures/materials.xml    2026-01-18 22:01:02.779748332 +0100
@@ -123,2 +123,3 @@
   <material name="smoke_nitro.png"       shader="alphablend" ignore="Y" />
+  <material name="smoke_nitro_nolok.png" shader="alphablend" ignore="Y" />
   <material name="smoke_yellow.png"      shader="alphablend" ignore="Y"/>
@@ -133,2 +134,3 @@
   <material name="nitro-particle.png"    shader="additive" ignore="Y" />
+  <material name="nitro-particle-nolok.png" shader="additive" ignore="Y" />
   <material name="skid-particle1.png"    shader="additive" ignore="Y"/>

textures/nitro-particle-nolok.png:

textures/smoke_nitro_nolok.png:

Apropos textures, this is how I've derived them:

I just thought that the regular nitro is, roughly speaking, blue. So I selected the "blue third" of the whole color spectre in GIMP for the input and the red one for the output. (In a browser, I'd just use hue-rotate.)

What do you think?

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[Al2Klimov]

Admittedly, there's still some blue light below the kart during nitro usage. I'm new here and have not found the necessary texture, yet. Maybe someone can give me a hint.

Done.

Bildschirmaufnahme_20260212_214044.webm