What It Means & How to Fix It in UE5

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🧠 Why You’re Seeing This Error

This error means your shader is trying to bind more texture objects than the hardware or shader model allows.

While similar to X4509 (which is about samplers), this error is specifically about the total number of texture objects — regardless of whether they share the same sampler.

Most platforms using Shader Model 5 allow up to 128 textures per shader.
On mobile platforms, the limit may be much lower (e.g., 16–32).

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💥 Example Error Message

error X4510: maximum number of textures exceeded (128)

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🛠️ Common Shader Scenarios That Cause This

❌ Too Many Unique Texture2D Bindings

Texture2D Texture0;
Texture2D Texture1;
...
Texture2D Texture129; // ❌ This pushes the count over 128

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❌ Overloaded Material Graphs in UE5

In the Material Editor:

• Each Texture Sample node counts as one bound texture
• If you’ve packed logic into one material (e.g. layering 10–20 textures for landscape or characters), it can hit the limit quickly

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❌ Using Textures for Data Instead of Packing

Texture2D HeightMap;
Texture2D NormalMap;
Texture2D AO;
Texture2D Specular;
// ❌ Separate textures for each property instead of packed RGB channels

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✅ How to Fix X4510 in UE5 – Step-by-Step

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✔️ 1. Reduce the Total Number of Unique Textures

Try to limit Texture2D declarations and Material texture samples to under:

• 128 for SM5 platforms
• 16–32 for mobile/SM4

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✔️ 2. Pack Multiple Maps into a Single Texture

Instead of:

Texture2D AOMap;
Texture2D RoughnessMap;
Texture2D MetallicMap;

Use:

Texture2D PackedMap; // R = AO, G = Roughness, B = Metallic

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✔️ 3. Use Texture Atlases

Combine multiple texture tiles into a single texture atlas:

// One texture, multiple UV regions
float2 adjustedUV = UVOffset + UV * UVScale;
float4 sampled = Atlas.Sample(Sampler, adjustedUV);

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✔️ 4. Consolidate Logic into Shared Material Functions or Instances

If you’re authoring massive layered materials:

• Reuse material functions
• Reduce per-layer texture count
• Disable unnecessary outputs (e.g., disable specular or normal per layer if unused)

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✔️ 5. For C++ Shaders: Use Arrays or Structured Buffers Where Possible

Instead of binding 100+ individual textures:

Texture2D MyTextures[16]; // Use arrays if supported on platform

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✅ Summary: How to Fix “error X4510: maximum number of textures exceeded” in UE5

Cause	Fix
More textures than platform supports	Reduce Texture2D usage below platform-specific limits
Separate maps per property	Pack multiple values into a single texture
Complex layered materials	Optimize with shared functions and texture reuse
Material editor overuse	Flatten or simplify texture-heavy branches