What Are Connected Textures (CTM)?

In vanilla Minecraft, every block face is drawn on its own. Place a wall of glass and you see the outline of each individual pane repeated across the whole window — a hard grid that instantly reads as “blocky.” Connected textures fix exactly that. When two or more matching blocks sit next to each other, CTM removes the seams between them and draws the group as one smooth, continuous surface.

The classic example is glass, but CTM is used for plenty of other blocks too:

• Glass and stained glass — borders disappear, leaving clean uninterrupted panes.
• Bookshelves — books line up across multiple blocks instead of restarting at every edge.
• Sandstone, quartz, and stone bricks — large flat builds lose the obvious tiling.
• Decorative blocks — packs can connect almost any block with the right files.

The result is subtle but powerful. Realistic and high-resolution packs lean on CTM heavily, because once you remove the repeating grid your builds stop looking like stacked cubes and start looking like real materials. It is one of the cheapest ways to make Minecraft feel less “Minecraft-y” without touching lighting at all. If your goal is the photoreal look overall, CTM pairs naturally with PBR depth and shaders — see what makes a texture pack look realistic.

CTM does not magically stretch one image across many blocks. Instead, it works like a smart tile system. The resource pack supplies a set of edge, corner, and centre tiles for a block, plus a small instruction file that tells the game which tile to use depending on a block’s neighbours.

When the game goes to render a face, the connected-textures engine checks the blocks around it. Is there a matching block on the left? On top? In the corner? Based on those answers, it picks the correct piece — an inner fill where the block is surrounded, an edge piece along the boundary, a corner piece where two edges meet. Stitch all those choices together and you get a surface with no internal seams, only a clean outer border.

On Java, packs define this with small .properties files, and the two common formats are:

• CTM — the full method, designed for surfaces that connect in every direction. Best for glass and large walls.
• CTM compact and repeat / random variants — lighter modes for things like varied stone or fixed patterns, where you want variety rather than perfect edge-matching.

Because the engine is only choosing which texture tile a face draws, CTM does not change Minecraft’s lighting or geometry. That is why it is relatively inexpensive compared with effects like shaders, and why it works even on fairly modest hardware.

Connected textures are not a vanilla setting. You need two things: a render engine that understands CTM, and a resource pack that actually includes the CTM data. The pack alone does nothing if the engine is missing.

With OptiFine

OptiFine has CTM support built in. Install OptiFine for your version, then open Options → Video Settings → Quality and set Connected Textures to Fancy. Make sure the resource pack with CTM data is enabled, and you are done. If glass still has borders, double-check that this one setting is on Fancy rather than Off or Fast.

With Iris (Fabric)

Iris is a shader loader — it does not render connected textures on its own. To get CTM alongside Iris, add the Continuity mod (a Fabric mod built specifically for connected textures), which reads the same CTM data OptiFine packs use. Install Fabric, drop both Iris and Continuity into your mods folder, enable your CTM resource pack, and connected textures will work with your shaders running. Unsure which loader to commit to? Our Iris vs OptiFine guide breaks down the trade-offs.

Where Optimum Realism fits

Optimum Realism is a photorealistic pack that uses connected textures (along with PBR materials) so your builds read as real surfaces, not repeated cubes. The free 64× edition is a great place to start, and higher resolutions are available through Patreon. It targets both Java (PBR with OptiFine or Iris + Continuity) and Bedrock RTX. New to installing packs? The install guide walks through it step by step, and the FAQ covers the common setup questions.

A lot of “why does my pack look wrong?” confusion comes down to CTM simply being off. The pack is fine — the connecting engine just is not running. Tell-tale signs that connected textures aren’t active:

• Glass shows a hard grid — every pane has a visible border instead of a clean sheet.
• Bookshelves restart at each block — the books don’t line up across a wall.
• Big stone or sandstone walls look tiled — you can clearly count each block.
• Custom block designs look chopped up — patterns the pack intends to span several blocks are cut at the seams.

If you are seeing that, run through this short checklist:

1. Turn CTM on. In OptiFine, set Connected Textures to Fancy. With Iris, confirm Continuity is installed and loaded.
2. Check the pack is active. The resource pack with CTM data must be enabled and sit above other packs in the list so it isn’t overridden.
3. Confirm the pack actually ships CTM. Not every pack includes connected-texture data; if it doesn’t, no engine can connect it.
4. Match versions. An OptiFine or Continuity build that doesn’t match your Minecraft version can quietly skip CTM.

One honest caveat: connected textures are a Java feature in this form. On Bedrock there is no OptiFine-style CTM system — Bedrock realism comes from RTX ray tracing and PBR materials instead, which is a separate topic. If your textures look flat or oddly shiny rather than un-connected, that’s a different problem; see why textures look flat or shiny. For the full list of explainers, head to all guides.