user: What is a texture atlas, how to make it and how to use it?

assistant: A texture atlas is a large image, or "sheet," which contains many smaller sub-images. Each sub-image is typically a texture for a 3D object or a frame of animation for a 2D sprite. The use of a texture atlas can significantly improve performance for real-time computer graphics, such as those used in video games.

The reasons for using texture atlases are primarily related to performance optimization:

1. **Reducing state changes**: Changing textures is often an expensive operation in terms of performance. If all the textures are on the same texture atlas, you can draw many different things with different textures in one go, which reduces the number of necessary texture binding operations.

2. **Reducing memory usage**: Modern GPUs can handle very large textures, so it can be more memory-efficient to have one large texture rather than many small ones.

Here is a simple way to create a texture atlas:

1. **Choose your images**: Decide on the images you want to include in your texture atlas. They should be related in some way, such as frames of animation for a single character.

2. **Create a new image**: This image should be large enough to contain all your smaller images. The dimensions of a texture atlas are usually a power of two (e.g., 256x256, 512x512, 1024x1024) due to hardware constraints, especially on older hardware. 

3. **Place your images**: Place each of your small images onto the large image. There should be no overlap between images.

4. **Create a coordinate map**: For each small image, record its location on the large image. This will allow you to find each image when you need it.

Here's how to use a texture atlas:

When rendering, you would look up in your coordinate map and adjust your texture coordinates to match the location of the texture you want to use on your atlas. For example, if you have a sprite that needs to use a texture located at (0.5, 0.5) on the texture atlas, you would adjust your texture coordinates to that location.

Please note that the creation process can be complex when done manually, especially for larger or more complicated texture atlases. For this reason, it is common to use software tools or libraries to create and manage texture atlases. Such tools often provide additional features, such as automatically packing images into the atlas in an efficient way.

user: Which tools would you suggest in order to create a texture atlas?

assistant: There are many tools available for creating texture atlases. Here are a few of the most popular:

* **TexturePacker** is a popular and easy-to-use tool that can be used to create texture atlases for 2D and 3D games. It offers a variety of features, including automatic packing, texture compression, and export options.
* **ProBuilder** is a Unity plugin that can be used to create and edit 3D models. It includes a built-in texture atlas creator that can be used to pack textures into a single atlas file.
* **Nvidia Texture Atlas Tools** are a set of command-line tools that can be used to create texture atlases. They offer a high degree of control over the packing process, making them a good choice for complex projects.
* **Texture Atlas Maker** is a free and open-source tool that can be used to create texture atlases. It is a simple tool, but it is effective for creating small texture atlases.

The best tool for you will depend on your specific needs and preferences. If you are looking for a simple and easy-to-use tool, then TexturePacker is a good choice. If you need more control over the packing process, then Nvidia Texture Atlas Tools or ProBuilder may be a better option. And if you are looking for a free tool, then Texture Atlas Maker is a good choice.

Here are some additional factors to consider when choosing a texture atlas tool:

* **Features:** The tool should have the features you need, such as automatic packing, texture compression, and export options.
* **Ease of use:** The tool should be easy to use, even if you are not a technical artist.
* **Price:** The tool should be affordable, especially if you are on a budget.
* **Platform support:** The tool should be available for the platform you are using, such as Windows, macOS, or Linux.

I hope this helps!