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Resource packs: the OptiFine features that work without OptiFine

By Ryleigh Newman · Published

Rockstar Shaders reads the OptiFine resource-pack formats itself, so a pack with connected textures, emissive block textures, custom entity models, random or emissive entity textures, or a custom sky works on Fabric with no OptiFine, no Continuity, no EMF and no ETF installed. Beyond Fabric Loader and Fabric API, nothing else is needed. The reader was written from the published formats, and Fresh Animations v1.10.5 has been verified in game.

I made Rockstar Shaders, and I wanted the packs people already have to work in it instead of sending them off to install three more mods. This page lists each format, the paths the files live at, what is recognized, what is skipped, and what the pack does on its own with no resource pack at all.

Download free (1.0.0) Modrinth (pending)Minecraft 26.3, Fabric, macOS on Apple silicon. Install guide. Releases and bug reports on GitHub.

Connected textures

Connected-texture rules are read from optifine/ctm/**.properties, the same folder OptiFine's own documentation gives (read on 2026-09-19). The methods handled are ctm, horizontal, vertical, horizontal+vertical, vertical+horizontal, top, random, repeat and fixed. Two kinds are recognized and skipped with a line in the log: ctm_compact, and the overlay methods, which OptiFine's list gives as overlay, overlay_ctm, overlay_random, overlay_repeat and overlay_fixed. A block a pack's rule covers is removed from the mod's own built-in class volume, so the built-in connected glass and sandstone never cut into a block the pack is already handling. If a pack connects most blocks and misses a few, the log line naming a skipped method is the first thing to look for.

Emissive block textures

Emissive block textures come from optifine/emissive.properties and the _e suffix on a texture: the emissive layer is drawn over the base texture as an emitter, without the z-fighting other loaders show on the same packs. The pack has one emission channel, so an emissive block from a pack blooms the same way the pack's own emitters do, and emissive entities go through the same channel. The reader looks for the same file and the same suffix OptiFine does, so a pack made for OptiFine goes in as it is. The look of the bloom itself is on the Post-processing page.

Custom entity models

Custom entity models are read from optifine/cem/: the .jem model files and the .jpm part files, with the full animation expression language, so an animated pack moves the way its author wrote it. Fresh Animations v1.10.5 is the pack I verified in game, and it is a fair test, because its own page calls it an animation overhaul for the game's creatures. That page says it needs either OptiFine with custom entity models on, or the Fabric mods Entity Model Features and Entity Texture Features (read on 2026-09-19); with Rockstar Shaders it needs none of those.

Random and emissive entity textures

Random entity textures are read from optifine/random/entity/, with the rules that pick a variant: biome, height, name, health, moon phase, time, weather and profession. Emissive entity textures, the glowing eyes and markings, are read as well, and an emissive entity blooms through the same emission channel as an emissive block. Together with custom entity models this is the whole of what a mob pack usually asks for, and it is read without Entity Texture Features or Entity Model Features installed.

Custom skies

Custom skies come from optifine/sky/world0/skyN.properties, and the legacy mcpatcher/sky/world0/ path is read too, with blend modes, fade times, rotation, speed, axis, weather and days rules, up to eight layers. The layers are drawn behind the blocky cloud deck, so the pack's clouds stay in front of them. One limit for now: a custom sky is not reflected in water or in the screen-space reflections. The pack's own sky and every setting for it are on Sky and Clouds.

What is built in without any pack

Four things work with no resource pack at all, from the Textures and Details page: connected glass (clear, tinted and stained), connected sandstone, Better Grass, and natural textures that turn sand, dirt, gravel, stone and grass tops per block to break the tiling. They are driven by a camera-centerd volume of block classes, 64 blocks on a side. The shader pack itself lives inside the mod's jar; there is no separate pack to download and nothing to put in the resource-pack slot.

The mods these formats usually need

On Fabric these formats are normally carried by three mods, and if you have used them you know the names. Continuity describes itself as a mod for efficient connected textures and implements OptiFine's connected textures, emissive block and item textures, and custom block layers. Entity Model Features implements OptiFine's custom entity models and requires Entity Texture Features, which does random and emissive entity textures. All three read on 2026-09-19 from their Modrinth pages. Rockstar Shaders reads the formats on this page itself. My record has no test of running those mods alongside it, so I cannot tell you what happens if you do; what I can say is that the features listed here need none of them. A format that is not on this page is not one the reader handles, so do not expect it to work.

Download free (1.0.0) Modrinth (pending)Minecraft 26.3, Fabric, macOS on Apple silicon. Install guide. Releases and bug reports on GitHub.

About the author. Ryleigh Newman wrote Rockstar Shaders and every page on this site. Facts about other packs and programs come from their own sites, with the date they were read. More about the project.

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Questions

Do I need OptiFine, Continuity, EMF or ETF for these packs?

No. Rockstar Shaders reads the OptiFine formats on this page itself. The only requirements are Fabric Loader and Fabric API.

Does Fresh Animations work with Rockstar Shaders?

Yes. Fresh Animations v1.10.5 was verified in game with no EMF or ETF installed. The pack's own page says it needs OptiFine or those two mods; here it needs neither.

Where do the files go in my pack?

The same OptiFine paths: optifine/ctm for connected textures, optifine/emissive.properties for emissive blocks, optifine/cem for entity models, optifine/random/entity for random entity textures, and optifine/sky/world0 or mcpatcher/sky/world0 for skies. The pack is a normal resource pack, enabled the normal way.

Why does one block in my pack not connect?

Its rule probably uses ctm_compact or an overlay method, which are recognized and skipped with a line in logs/latest.log. Search the log for RockstarShaders to find it.

Do custom skies show in water reflections?

Not yet. A custom sky is drawn behind the blocky cloud deck but is not reflected in water or in the screen-space reflections.