Texel density in Blender: calculate it, check it, keep it consistent
Short answer
Texel density is the number of texture pixels per metre of surface. To calculate it in Blender, multiply the texture resolution by the share of UV space that an edge takes up, then divide by the real length of that edge. Blender does not display it natively: the free Texel Density Checker add-on measures it and applies it to a whole selection of objects.
Two objects textured in 2K do not necessarily have the same level of detail: a 2048 × 2048 texture stretched over a ten-metre wall looks blurry, while the same texture on a mug looks too fine. Texel density is how you measure that level of detail and even it out across a whole scene.
What is texel density?
A texel is a texture pixel. Texel density is the number of texels per unit of length in the scene, in pixels per metre (px/m) or pixels per centimetre (px/cm): 1024 px/m and 10.24 px/cm are the same value. It depends on three things: the resolution of the texture, the space the object takes up in UV space and the real size of the object in the scene.
A consistent texel density is the real goal. When it varies from one object to the next, the eye immediately picks out blurry surfaces next to sharp ones, even if each texture is of good quality.
How do you calculate texel density?
Take an edge of the model whose real length you know, and measure the space it takes up in the UV Editor, where the whole UV space equals 1:
texel density = texture resolution × edge length in UV ÷ real edge length
Example: a 2048-pixel texture, and an edge that covers half the UV space (0.5) and measures 1 metre in the scene. 2048 × 0.5 ÷ 1 = 1024 px/m, or 10.24 px/cm. For the measurement to be accurate, apply the object's scale first (Ctrl+A, then Scale): otherwise Blender measures the object as it was before scaling.
Which value should you choose?
There is no standard, only common reference values in game production, to adapt to the distance from the camera:
| Use | Common reference value | In px/cm |
|---|---|---|
| Objects seen from a distance, background scenery | 256 to 512 px/m | 2.56 to 5.12 |
| Third-person game | 1024 px/m | 10.24 |
| First-person game, objects seen up close | 2048 px/m | 20.48 |
| Close-ups in a still image or a film | Higher, depending on the framing | - |
For a still image or an animation rendered in Blender, the right value depends on the framing: an object that fills a quarter of a 4K image does not need more texels than it has pixels on screen. Beyond that, the texture costs memory without adding anything visible.
How do you check texel density in Blender?
Blender has no built-in tool to display it. Three methods, from the simplest to the most precise:
- The checker grid. In the UV Editor, create an image of the UV Grid or Color Grid type and apply it to every object. If the squares are the same size everywhere in the 3D Viewport, the texel density is consistent.
- Calculating by hand, with the formula above, on one edge of each object.
- The Texel Density Checker add-on, free and open source: it measures the texel density of a selection, applies it to other objects by resizing their UVs, and colours the model by density so you can spot the differences. It is a widely used tool for this job in Blender.
Making texel density consistent across a scene
- Apply the scale of every object.
- Choose a target value based on the framing and the final medium.
- Measure a reference object, then apply the same value to the others, with the add-on or by resizing their UVs.
- If a large object cannot reach the target value within a single texture, spread it over several UDIM tiles, which Blender supports.
Texel density, video memory and render time
Texel density does not speed up a render in itself, but it avoids waste. 8K textures on objects that only show a fraction of them fill up the memory of the graphics card. When the scene no longer fits in that memory, Cycles slows down sharply or stops with an error. Making texel density consistent often cuts the weight of the textures with no visible loss. To find out how much video memory to aim for, see the guide which PC for 3D rendering.
Frequently asked questions
What is texel density?
It is the number of texture pixels (texels) per unit of surface in the scene, expressed in pixels per metre or per centimetre. A consistent texel density gives every object the same level of detail, whatever its size.
What texel density should you choose?
There is no standard. Common reference values in game production: about 512 px/m for objects seen from a distance, 1024 px/m (10.24 px/cm) for a third-person game, 2048 px/m for objects seen up close. What matters is keeping the same value on every object in a scene.
Does Blender show texel density?
Not natively. You work it out from the size of the texture, the area it covers in the UV Editor and the real size of the object, or you use the free Texel Density Checker add-on, which measures it and applies it to a selection.
Does texel density affect render time?
Indirectly, yes. A texel density that is too high calls for larger textures than you need, and they take up video memory. When the scene no longer fits in the memory of the graphics card, the render slows down sharply or stops with an out-of-memory error.
Rendering the animation on TURNA
When a scene is already well optimised and the frame count is what takes the time, the remaining lever is rendering several frames at once. TURNA does this for Blender: an add-on (Blender 4.0 to 5.2, Cycles and Eevee) sends the scene in one click, and the frames are split across 1, 2, 4 or 8 GPUs in parallel, RTX 5090 first and RTX 4090 when none is free. The add-on shows the estimated cost before anything starts. Prices start at €2.90 per hour, billed on the time actually used, with a 30-second minimum, and new accounts get €25 of free credit. A single still image is still rendered by one machine, so the gain is on animations. Tiers and worked examples are on the Blender render farm page.
If a scene with heavy textures saturates your graphics card, the article fixing the Out of Memory error in Blender (in French) details the settings that free up video memory.
