A texel density walkthrough for Blender artists
In the event you’ve ever performed video video games and appreciated the extent of consistency intimately (and even observed a scarcity thereof) among the many 3D components round your viewpoint as you traversed the sport world, you might have skilled the great (or unhealthy) utility of an idea often known as texel density. Texel density refers back to the variety of texture pixels (texels) per unit of 3D floor space. To create a way that the varied props and units belong to the identical world, 3D artists should preserve a constant texel density throughout all of the 3D fashions.
For video video games, texel density is especially essential as a result of it straight impacts each the immersion of the gamers and the efficiency of the sport engine. A decrease texel density can enhance recreation efficiency however at the price of decrease texture high quality, whereas the next texel density can enhance texture high quality however can negatively influence recreation efficiency.
When creating 3D renders as stills or animations, managing texel density is simply as essential for a similar causes, and on this article, we’ll take a better have a look at how to consider texel density because it pertains to creating 3D scenes normally, and the right way to do it in Blender utilizing an awesome addon by Ivan Vostrikov.
An intuitive understanding of texel density
Let’s take a look at these rock fashions:

One thing doesn’t really feel proper, does it? If we take a better look, we will see that the smallest rock has very crisp textures, whereas the most important rock’s textures are blurred, and the remaining rock is at a clumsy center. These rocks all share a single UV house, however the sizes of their UV shells don’t mirror their precise dimension within the digital house they occupy.


By resizing the UV shells of every rock in accordance with its dimension, we’ll get a extra constant degree of constancy throughout all three. We are able to do that by making use of a checker texture on the fashions and resizing the shells till the checker tiles on all rocks are the identical dimension.


That, in probably the most primary phrases, is texel density. Whereas the texel density of any given object or floor is an absolute worth, the true significance lies in how proportionate the densities of surrounding objects are to it. For example, let’s say we had been getting ready to create a render based mostly on a picture we discovered on Pinterest:

Texel density in scene creation
As we make our plans, it will profit us in a while to find out what texel density to work with as early as now. For this picture, the bottom might function a great place to begin because it’s comparatively near the place the digital camera can be. Let’s begin by making a aircraft with a checker map texture 4096 x 4096 pixels in dimension:

The feel element at this dimension and digital camera vary appears ample, so let’s go along with it! Now that we’ve some extent of reference, we’d begin creating our fashions and unwrapping them. Let’s assume that’s over and completed with.
Right here’s our scene at this level:

For this text, we’ll be working with the foreground components and the characters’ clothes, however we’ll save the mountains and the characters themselves for a future article about UDIMs. Keep tuned!
We might approximate the texel density for every of the weather based mostly on our checker mapped floor aircraft, however that may be tedious and due to the work of Ivan Vostrikov, pointless! As a substitute, we’ll use his helpful Texel Density Checker addon, which is out there without cost, however definitely value leaving a donation for!

Let’s pull up the addon from inside our UV Editor:

Now we have our floor aircraft’s UV shell occupying your complete UV grid, and we all know our checker texture has a 4K decision, so we’ll set our Texture dimension accordingly and (arbitrarily) have our items at pixels per meter.
By hitting “Calculate TD” we will see that our shell occupies virtually one hundred pc of the 0-1 grid, and has a density of 524.665 px/m. Let’s hit “ Calc-> Set Worth” to ascertain this worth as the purpose of reference for our different UVs:

Now if we choose some other unwrapped mesh, we will use the “Set My TD” button to scale the UV shells or islands in proportion to the reference worth.

Beginning with the tent flaps, let’s choose all of the islands within the UV Editor and select “Common” for the “Set Methodology” area within the texel density checker panel. Selecting common will scale the entire chosen islands proportionally to the worth that was set.

Let’s do the identical for the tent poles.


Because the poles are a lot smaller in comparison with the bottom, the islands have shrunk correspondingly, and we’re now left with numerous empty house within the UV Grid, which might be a waste of texture house. Listed below are some methods we will optimize issues:
1. Change Texture Dimension
If we needed a devoted set of textures to this mesh, we might scale back the feel dimension.

By altering the Texture Dimension from 4096 to 2048 and hitting “Set My TD” once more, we will make use of extra texture house.
2. Set Customized Texture Dimension
A dimension of 1024 would have been preferrred, however the islands had been just a bit too huge for the grid. We might set a customized dimension to get round this, however that may imply having to work round any unpredictable tiling throughout our texturing section.

3. Share UV Grid with different fashions.
Sharing the UV Grid with different meshes is the optimum method to maximize texture house and scale back the quantity of maps your render engine should compute throughout rendering. This makes the undertaking file lighter and render sooner, although by how a lot relies on the variety of fashions within the scene that use picture textures. If we had been to animate this scene and use a web based render farm to render out frames, this methodology would assist immensely in driving down bills.
The draw back of this strategy nevertheless, is that texturing every mesh that shares this UV grid would require extra manoeuvring in our texturing utility, particularly if the meshes are supposed to have completely different floor traits.
In any case, we’ll use this tactic for our demonstration.
A be aware about UV format
When utilizing Texel Density Checker, there could be situations the place setting the texel density on a number of islands directly results in overlapping UVs. A workaround for that is as follows:

Use Blender’s annotate software to mark the size of a shell. Then use the Pack Islands operation to make sure that every thing is laid out nicely.

After, merely scale the islands down till the shell you used as reference aligns together with your mark.

For the sake of brevity, let’s take a look on the remaining UV layouts for all of the objects that had been achieved utilizing the steps outlined to this point, (with just a few adjustments right here and there to some seams in meshes for higher format).





Here’s a density verify for the render:

Each factor that we labored on within the shot has a constant Texel Density!
And right here’s an preliminary render to function our work in progress:

Parting phrases
Whereas the idea of texel density is extra steadily mentioned amongst recreation artists, hopefully this text has proven how important it’s for 3D rendering normally, in addition to the right way to begin incorporating it into your apply in Blender. Remember nevertheless, that exterior of making property for video games there are a lot much less technical constraints imposed upon you, and so the age-old knowledge of “if it seems good, it IS good” bears remembering. I hope this text was helpful to you, and as at all times, Completely satisfied Rendering!