Space Warp

[FabianHummel]

Idea

The plan is to create a custom skybox with the rendertype_item_entity_translucent_cull core shader. The main issue is that core shaders don't have a good way to modulate variables based on scoreboard values. I have two options in mind:

• create 254 textures + models (excluding alpha=0 and 255) each with a different transparency value and retrieve it in the shader by reading the texture's alpha channel. (I could probably also use the RGB channels, but I still need 254 instances)
• use a single texture + model in combination of the dye-attribute. Maybe the color gets blended in automatically before the shader runs? Then I could easily change the value during runtime.

Helpful/Inspirational Resources

• https://youtu.be/ZGpP5I_0qrg?si=Dj08caiITQPonYCk
• https://discord.com/channels/154777837382008833/157097006500806656/1420497051124498602
• https://discord.com/channels/154777837382008833/507995770109165579/1396375305924640829
• https://github.com/Meekiavelique/minecraft-vanilla-skybox
• https://github.com/BalintCsala/minecraft-vanilla-skybox

[FabianHummel]

Edit: Thankfully the second option works out great. No need for dozens of models + individual textures. I can modulate core shaders with the dye item-component and therefore smoothly interpolate e.g. the speed and density of the space warp in real time by encoding + decoding the RGB values to and from an integer.

After implementing a shader heavily inspired by this Godot tutorial: https://www.youtube.com/watch?v=ZGpP5I_0qrg, this is the result:

Screen.Recording.2025-11-30.at.10.09.19.Warp.Shader.fully.working.webm

[FabianHummel]

With the option above this comment there is a slight problem with the resolution of skybox rotation. By only using a single model/texture and the dye attribute (vec3) there are only $\sqrt[3]{2^{24}}=256$ possible values for each axis, which is very unpleasant to look at.

However, by introducing more model/texture combinations (different alpha-values) we can increase this number drastically and ultimately achieve a higher rotational resolution. By splitting each axis into four sections (0°-90°, 90°-180°, 180°-270° and 270°-360°) -> $4^3=64$ models with $64$ textures (from alpha value 191 up until to 254) we have $\sqrt[3]{2^{24}*64}=1024$ possible values per axis which is enough for the space skybox.

[FabianHummel]

The plan is to change this effect to only exist around a small box around the spaceship itself due to several issues including shader parameter resolution and overall wrong appearance when combined with the rest of the space dimension.

Essentially, these things will going to happen:

• the effect's background is transparent
• the speed and intensity is constant
• the 64 different models are obsolete now and will be replaced with a single model
• the opacity is modulated depending on the speed of the spaceship
• the actual skybox (stars) is something entirely different, described in Space Skybox #6