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Preparing Textures

Terrain3D supports up to 32 texture sets using albedo, height, normal, and roughness textures, each set are channel packed into 2 files. This page describes everything you need to know to prepare your texture files. Continue on to Texture Painting to learn how to use them.

Table of Contents

Texture Requirements

Texture Files

Typically "a texture" say rock comes as a pack of individual texture files: albedo/diffuse/base color, height, normal, smoothness/roughness, ambient occlusion (AO). For maximum efficiency we provide the option of packing these 5 separate files into 2.

Terrain3D is designed for texture sets that are channel packed as follows:

Name Format
albedo_texture RGB: Albedo, A: Height
normal_texture RGB: Normal map (OpenGL), RGB: AO, A: Roughness

The terrain can work without the height, normal, ao, or roughness maps. But then you won't have height blending, roughness, or the other features. That may be fine for a low-poly or stylized terrain, but not for a realistic one.

Textures can be channel packed using the Pack Textures... option in the Terrain3D menu at the top of the viewport (recommended), or in Gimp. Photoshop or Krita are possible, but working with alpha channels can be a bit challenging.

Texture Sizes

All albedo textures must be the same size, and all normal textures must be the same size. Each type gets combined into separate Texture2DArrays, so their sizes of the two arrays can differ.

Double click any texture file and the inspector will show you the size. The demo textures are 1024x1024.

For GPU efficiency, it is recommended that all of your textures have dimensions that are a power of 2 (128, 256, 512, 1024, 2048, 4096, 8192), but this isn't required.

Compression Format

All albedo textures must be the same format, and all normal textures must be the same format. Albedo and Normals are combined into separate Texture2DArrays, so the two can have different formats.

Double-clicking a texture in the FileSystem panel will display it in the Inspector with the current converted format of the file, size, and mipmaps. Settings may be adjustable on the Godot Import tab.

Type Supports Format
PNG Desktop, Mobile RGBA, converts to DXT5 or BPTC (HQ). In Godot you must go to the Import tab and select: Mode: VRAM Compressed, Normal Map: Disabled, Mipmaps Generate: On, optionally check High Quality, then reimport each file.
DDS Desktop BC3 / DXT5, linear (intel plugin), Color + alpha, mipmaps generated. These files are used directly by Godot and are not converted, so there are no import settings.
Others Other Godot supported formats like KTX, TGA, JPG, WEBP should work as long as you match similar settings to PNG.
EXR While EXRs can work, they store color data as 16/32-bit float, not 8-bit integer. Don't use them for terrain textures unless you know what you're doing.

To get the highest quality compression on desktop, use either:

  • Use PNG with the high quality option in Godot (BC6/BPTC). Pack with our channnel packer and mark HQ. Godot does not currently support importing anything higher than BC3/DXT5 in DDS files.
  • DDS (BC3/DXT5) made in Gimp are recommended over using the default PNG settings, which produces poor quality BC3/DXT5 files. When creating DDS files in Gimp you have a lot more conversion options, such as different mipmaps filtering algorithms which can be helpful to remove artifacts in reflections (eg try Mitchell).

The demo textures are PNG imported as HQ which are converted to BPTC.

You can create DDS files by:

You can create KTX files with Khronos' KTX tools.

Texture Content

Seamless Textures

Make sure you have seamless textures that can be repeated without an obvious seam.

Height Textures

If creating your own height textures, aim for a central point of grey (0.5) with bumps and divots above and below that value. Adjust the contrast so that troughs and peaks reach just about 0 and 1.

Normal Map Format

Normal maps come in two formats: DirectX with -Y, and OpenGL with +Y. Both formats should be normalized.

DirectX can be converted to OpenGL and vice versa by inverting the green channel in a photo editing app, or within our texture packing tool.

They can often be identified visually by whether bumps appear to stick out (OpenGL) or appear pushed in (DirectX). The sphere and pyramid on the left in the image below are the clearest examples.

:target: ../_images/tex_normalmap.png

Natural textures like rock or grass can be very difficult to tell. However if you get assets made for a certain engine like Unreal or Unity, you can generally assume their format and convert as needed. On occasion artists get it wrong though, so if the lighting looks off on your object, try inverting the normal map.

Software DirectX OpenGL
3DS Max ✓
Blender ✓
Cinema 4D ✓
CryEngine ✓
Godot Engine ✓
Houdini ✓
Marmoset Toolbag ✓
Maya ✓
Substance Painter ✓
Unity ✓
Unreal Engine ✓
Zbrush ✓

Roughness vs Smoothness

Some "roughness" textures are actually smoothness or gloss textures. You can convert between them by inverting the image in an image editor, or in our texture packing tool.

You can tell which is which just by looking at distinctive textures and thinking about the material. If it's glass it should be glossy, so on a roughness texture values will be near 0 and the texture will appear mostly black. If it's dry rock or dirt, it should be mostly white, which is near 1 roughness. A smoothness texture would show the opposite.

Ambient Occlusion

Our built in texture packing tool allows you to easily combine AO texture maps into your normal texture set. This is done by a clever technique of expecting your normal map is normalized, then scaling the vector by the AO value.

AO maps are not required for any texture. You can even mix and match on different textures, unlike with sizes or formats. If you haven't included an AO texture, AO will be approximated from the normal map.

If you wish to apply AO to your textures manually or in another tool, ensure your normal map is normalized, then pack AO with: unpacked_normal_vector * (sqrt(ao) * 0.5 + 0.5).

Channel Pack Textures in Terrain3D

We recommend you use our built in tool to pack textures.

:target: ../_images/terrain3d_menu.png
  1. At the top of your viewport, click the Terrain3D menu, then Pack Textures.
  2. Select your textures for albedo and height.
  3. Optionally, select textures for normal, roughness, and if desired ambient occlusion
  4. Optionally, convert a DirectX normal map to OpenGL, or smoothness to roughness map.
  5. Optionally, enable Orthogonalise normals if you see a reflective checkerboard pattern appear when using detiling.
  6. Click Pack Textures As... and save the resulting PNG files to disk.
  7. Go to the Import tab and one at a time, select your new PNG files, specify the following settings and click reimport.
    • Mode: VRAM Compressed
    • Optional: High Quality: On if you wish BPTC instead of DXT5.
    • Normal Map: Disabled
    • Mipmaps Generate: On

Make sure to reimport both files. Double click each file in the filesystem and ensure the inspector reveals the expected format and size. All of the files you put in your texture list must match.

Channel Pack Textures with Gimp

Note: AO packing normals manually is complex and not reccomended. The formula used is: unpacked_normal_vector * (sqrt(ao) * 0.5 + 0.5)

  1. Open your RGB Albedo and greyscale Height files (or Normal and Roughness).

  2. On the RGB file select Colors/Components/Decompose. Select RGB. Keep Decompose to layers checked. On the resulting image you have three greyscale layers for RGB.

  3. Copy the greyscale Height (or Roughness) file and paste it as a new layer into this decomposed file. Name the new layer alpha.

This would be a good time to invert the green channel if you need to convert a Normalmap from DirectX to OpenGL, or to invert the alpha channel if you need to convert a smoothness texture to a roughness texture.

  1. Select Colors/Components/Compose. Select RGBA and ensure each named layer connects to the correct channel.

  2. Now export the file with the following settings. DDS is highly recommended.

Also recommended is to export directly into your Godot project folder. Then drag the files from the FileSystem panel into the appropriate texture slots. With this setup, you can make adjustments in Gimp and export again, and Godot will automatically update with any file changes.

Exporting As DDS

  • Change Compression to BC3 / DXT5
  • Mipmaps to Generate Mipmaps.
  • Optionally, change the Mipmap Options Filter, such as to Mitchell if you get reflection artifacts in your normal+roughness texture.
  • Insert into Godot and you're done.
:target: ../_images/io_gimp_dds_export.png

Exporting As PNG

  • Change automatic pixel format to 8bpc RGBA.
  • In Godot you must go to the Import tab and select: Mode: VRAM Compressed, Normal Map: Disabled, Mipmaps Generate: On, then click Reimport.
:target: ../_images/io_gimp_png_export.png

Where to Get Textures

Texture Creation Software

You can make textures in dedicated texture software, such as those below. There are many other tools and ai texture generators to be found online. You can also paint textures in applications like krita/gimp/photoshop.

  • Materialize - Great free tool for generating missing maps. e.g. you only have an albedo texture that you love and want to generate a normal and height map
  • Material Maker - Free, open source material maker made in Godot
  • ArmorLab - Free & open source texture creator
  • Substance Designer - Commercial, "industry standard" texture maker

Download Textures

There are numerous websites where you can download high quality, royalty free textures for free or pay. These textures come as individual maps, with the expectation that you will download only the maps you need and then channel pack them. Here are just a few:

FAQ

Why do we have to channel pack textures? Why is this so difficult?

You don't have to. You can use just the albedo map, or also the normal map, without the others. However if you want a realistic terrain with height blending and roughness, you need all of the maps. You could have 5 different texture maps in memory, or pack that down to 2 maps and save precious VRAM.

Channel packing is a very common task done by professional game developers. Every pro asset pack you've used has channel packed textures. When you download texture packs from websites, they provide individual textures so you can pack them how you want. They are not intended to be used individually!

We offer a built in Pack Textures tool, found in the Terrain3D menu at the top of the viewport that facilitates the texture creation process within Godot. Packing can be done in 30 seconds.

Finally, we provide easy, 5-step instructions for packing textures with Gimp, which takes less than 2 minutes once you're familiar with the process.

If we want high performance games, we need to optimize our games for graphics hardware. A shader can retrieve four channels RGBA from a texture at once. Albedo and normal textures only have RGB. Thus, reading Alpha is free, and a waste if not used. So, we put height / roughness in the Alpha channel.

We could have the software let you specify individual maps and we pack textures for you at startup, however that would mean processing up to 160 images every time any scene with Terrain3D loads, both in the editor and running games. Exported games may not even work since Godot's image compression libraries only exist in the editor. The most reasonable path is for gamedevs to learn a simple process that they'll use for their entire career and use it to set up terrain textures one time.

What about Emissive, Metal, and other texture maps?

Most terrain textures like grass, rock, and dirt do not need these.

Occasional textures do need additional texture maps. Lava rock might need emissive, or rock with gold veins might need metallic, or some unique texture might need both. These are most likely only 1-2 textures out of the possible 32, so setting up these additional options for all textures is a waste of memory. You can add a custom shader to add the individual texture map.

Why not use Standard Godot materials?

All materials in Godot are just shaders. The standard shader is both overly complex, and inadequate for our needs. Dirt does not need SSS, refraction, or backlighting for instance. See a more thorough explanation.

What about displacement?

Godot doesn't support texture displacement via tessellation or geometry shaders in the renderer. However, we provide the option of subdividing the terrain mesh, to allow textures to displace verteices. For further details see Displacement.

Effects like depth parallax or occlusion mapping etc require many samples in fragment, which can be prohibitivley expensive when applied to already complex terrain shaders. There are alternatives that might prove useful in the future.

What about...

We provide a base texture with the most commonly needed terrain options. Then we provide the option for a custom shader so you can explore what about on your own. Any of the options in the Godot StandardMaterial can be converted to a shader, and then you can insert that code into a custom shader. You could experiment with Godot's standard depth parallax technique, or any of the alternatives above. Or anything else you can imagine, like a sinewave that ripples the vertices outward for a VFX ground ripple effect, or ripples on a puddle ground texture.