3D Models Buying Guide Part 2
3D Models Buying Guide Part 2 is about Textures, Materials and UV Mapping – There are 2 kinds of customers for 3D models.One who knows about 3D modeling and understand the different terms and names such as UV mapping, Textured, Low-Poly etc. and the others who are interested in 3D models, want to use 3D models for their projects but these terms might sound unfamiliar to them.
This article is for the latter group to whom would like to get better understanding in an easy way of Textures, Materials and UV Mapping.
Textures and Materials
Many people think textures and materials are the same…they are not the same.
Textures basically responsible for the visual look of the model ie.stone, moss, silk, wood etc. and materials define the type of the look ie. shiny, reflective, transparent or opaque etc.
These 2 together give the final look of the model.There are untextured models and/or models without materials.
Important : depending on the type of the 3D models they might come without textures and materials but they can also be perfectly used because the basic essential of a model is the geometry.A simple mesh is basically a naked 3D model and some models don’t need clothes.
Examples for models without textures and materials with Overlapping UVs but still ready to render and can be perfectly used for many projects :
This one is a game ready model with hand made UV mapping and baked textures :
Handmade UV map sample :
What is baked texture?
A texture stores important information such as color, diffusion, ambient occlusion (AO), lightmap, normal map, bump map etc.These are mostly separate textures (individual image files such as jpg, png, tiff etc.) and they need to be applied to the corresponding channels in the material/texture setup process.Not every model needs that many maps.Usually game models have many textures and also usually game models use baked textures.The most common ones are : color, normal, ambient occlusion and specular is also widely used but ie. opacity map and luminance map are used a lot too.
Baked textures are textures that are sticked to the UV map of a certain 3D model therefore they are basically drag and drop models.
For example a model made in Cinema 4D without baked textures would look bad after importing it to a game engine or another 3D software.But if the model has baked textures then it will look the same in every game engine and/or 3D software.
You’re reading 3D Models Buying Guide Part 2 – you can always check out 3D Models Buying Guide Part 1 about 3D Models Geometry
This is a very confusing subject for those who aren’t deeply in 3D.I try to explain it as simple as possible for better understanding.
UV maps are responsible for the look of the texture of the 3D model.UV map is basically the skin of the 3D model and the texture is projected onto this skin (just like a tattoo that covers the full body).If you the skin isn’t setup well the tattoo will look distorted.If the UV map isn’t setup well the texture will look distorted.
You can see different descriptions of UV maps belonging to the actual 3D models.
Overlapping UV / Non-Overlapping UV / Mixed UV / Unwrapped UV – this is a day long (and super boring) explanation so instead of trying to explain these deeper, I try to describe what these kinds of UVs can be used for.
If a model has overlapping UVs it means :
1. there is only material (or nothing) applied to it and there is no texture coming with the model.It’s not necessarily a bad thing because there are many model types that don’t really need to have Non-Overlapping UV or need of any material.(see The City Project 3D Models for example)
2. the model has materials and textures but it works well with properly projected textures and materials only in its native format.
For example if a model was made in Cinema4D and has overlapping UVs and also has materials and textures it will be a drag and drop model ONLY for C4D (.c4d file) users.Those who want to use an exchange format such .obj or .fbx they have to rework the textures in their 3D software such as Maya, Blender etc.
Here is a sample for this kind of model :
In this case all parts of the skin are projected on a flat UV map and none of its parts overlap each other.
It’s good because if multiple 3d file formats offered in the download that usually means that all of them work fine and look the same IF the textures are baked to he model.
If a model has only Non-Overlapping UVs but not baked textures it might still cause an issue in the look of the model if you want to use a non-native format.
What is native file format?
For example if a model was made in Cinema 4D than the native file format is .c4d. All other formats such as .obj, .fbx, dae, etc. are exchange formats that can highly increase file compatibility amongst different 3D softwares and game engines.
If you want the textures to look fine in every exchange format such as .obj, .dae, .fbx etc. the UVs need to be set to non-overlapping and also textures should be baked to the model.
It’s ONLY important if you want to license a drag and drop model (a model that is basically ready to render).
Useful to know : If a model has baked textures than it means it has Non-Overlapping UVs but if a model has Non-Overlapping UVs it doesn’t mean it has baked textures.
Important : not every model should have non-overlapping UV but every game-ready model (uniquely designed for video games usage) must have non-overlapping UVs. Also if the game model comes with textures they need to be baked to the model.
Before purchasing a model how do I know if it has baked textures?
This information is usually in the description of the 3D model product page.Also you should check the preview images as there might be some images presenting baked models.
Overlapping and Non-Overlapping UVs included in the model.
These are usually not game ready models but made for CG renders.
Unwrapped UV is a Non-Overlapping UV :
1. the artist manually creates the UV map of a 3D model.These are mostly done for character modeling (organic 3D models) and also for example rocks.By using this method it means that you can easily paint your custom texture in a 2D app like Gimp.Of course, 3D painting works as well.
This is also the most effective way to use the UV area for your UV map altough the most time consuming but it can generate the best results.
2. the 3D software automatically unwraps the UV with the smallest possible distortion.These UVs are not optimized for 2D painting but are perfect for 3D painting.
This method is usually used for ie. hard surface models such as buildings.
Which is better?
It depends on the model type.Manually unwrapping UVs can be a total waste of time for certain model types but in other hand automatic UV mapping can cause terrible results on certain models.None of them is better.
It’s something like to compare a monster 6×6 wheel truck and a cabrio sport car.Each of them can be used great on its own ground.I mean it doesn’t matter if a cabrio is super fast on a heavy terrain and also you don’t need 6×6 drive on the highway.
Final conclusion on Uvs :
Do not let yourself discouraged from licensing a 3d model because of a seemingly confusing UV description.If you like the model but you’re unsure, it’s useful to ask the artist.You can always do that on CGTrader (NOT on Turbosquid) and also if you’re interested in boscorelli3D’s models you are welcomed to ask via boscorelli.net / sellfy.com / boscorelli and also on Cgtrader.Honest answers guaranteed.If you finally decide not to license that’s much better than license and become an unhappy customer.I want my licensors to use the models and be happy.
Before licensing ask these from yourself :
What I want to use the model for?
If games – model is optimally a drag and drop model with baked textures.
If games – model can come without textures but make sure it’s not a high-poly model.
Usually if a game model with baked textures look good on the preview images (with baked texture) than it’s 99% that the model works flawlessly in any game engine and 3D software.
If CG renders – model should look good.It’s as easy as that.No shading errors on the preview images and also make sure to check the wireframe view.Depending on the model type it can have Overlapping or Non-Overlapping UVs and also can come with or without textures and/or materials.This is very flexible.If you’re unsure ask before purchase.
I hope this article helps you understanding this quite confusing subject better.Thank You for reading!
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End of 3D Models Buying Guide Part 2, the next part will be 3D Models Buying Guide Part 3 about Licensing and Licenses