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Materials and Textures

James
  • Updated

    Sketchfab's viewer is based on PBR (Physically Based Rendering) methodology.

    Materials

    Sketchfab supports multiple materials and objects in your scene. Give each material a unique name because the 3D editor merges objects by material name. Avoid special characters when naming.

    If possible, you should join every mesh that shares a material because it helps performance.

    When uploading the Wavefront (.OBJ) format, the material library file (.MTL) should be included for best results.
    Sketchfab supports a maximum of 100 materials. Learn more here.

    3d_material_model_settings.png

    Colors

    If you are not using texture images, you can choose a color for any slot from the color picker.

    3d_model_materials_color_picker_settings.png

    See also Vertex Colors.

    Textures

    Textures are images mapped to the surface of your model. For details on shaders/texture slots, see Materials (PBR).

    Importing

    Upload textures with your model file or embed textures in the model file (e.g. .BLEND, .FBX). You can put image files in the same folder/directory as the model file, or a sub folder/directory. If your textures are properly referenced by the model file or use our naming conventions, they will be automatically applied to your model.

    When using the Wavefront (.OBJ) format, the material library file (.MTL) should be included for best results.

    If you need to add textures after uploading, you can use the texture manager or drag and drop images into their slots in the material editor.

    Sketchfab 3d model material import texture

    Sketchfab 3d model material texture settings

    Sketchfab 3d model material texture settings

    Supported Formats

    Different image formats can be used depending on whether you uploaded them together with the model file, or upload them in 3D Settings after the model is processed

    During upload:

    • .JPG
    • .PNG
    • .TIFF
    • .TGA
    • .DDS
    • .GIF
    • .BMP
    • .VTF
    Anything that is not .JPG or .PNG is converted to .PNG. See Processing & Compression.

    In 3D Settings:

    • .JPG
    • .PNG
    • .TGA
    .TGA is converted to .PNG.
    The maximum supported file size per texture is 75MB and the maximum supported resolution is 8192px × 8192px. However, we recommend staying well below this limit whenever possible. Such large images use a lot of resources, and are usually overkill. See Processing & Compression.
    Sketchfab only support RGB and Linear images. Using another color space such as CMYK can have unexpected results.

    Processing & Compression

    Textures are compressed to minimize model download times. We convert any image that is not .JPG or .PNG to .PNG. Then, we generate compressed versions of every texture. The format and level of compression depends on the image attributes and channel requirements: RGB, Luminance, or Alpha. We do our best to minimize file size without affecting visual quality.

    We also generate multiple resolutions of each texture at every "power of 2" between 32×32 pixels and the original (up to 8192×8192). For example, if you upload a 1024×1024 texture, we will generate 32, 64, 128, 256, and 512 versions. Depending on your device, these are used in "LD" and "SD" modes in the viewer.

    For performance reasons, non-"power of 2" textures will not be used; the viewer uses to the closest, smaller version.

    Textures are re-processed each time you change Material settings, with a small delay. This can take 10-15 minutes to complete. 3D Settings always uses full resolution, uncompressed textures.

    If you experience issues with compression artifacts, especially on normal maps ("blocky" or "pixelated" textures, please see this post.

    Automatic PBR Mapping

    Use our texture naming conventions to help us automatically choose settings and apply textures to the right shader slots. The format is "MaterialName_suffix.extension". For example, if you have a material named "Material1", you could name your textures like "Material1_diffuse.png", "Material1_metallic.png", etc.

    Avoid material names with special characters, especially periods '.', underscores '_', and hyphens '-' because it can break the match.

    Avoid material names with matching substrings, for example "handle" and "woodenhandle" in the same scene.

    If the model has only one material, we will apply textures based on the shader name match regardless of the material's name or the position of the string in the name of the image file.

    These are the strings we look for in the suffix:

    • Diffuse / Albedo / Base Color: 'diffuse', 'albedo', 'basecolor'
    • Metalness: 'metalness', 'metallic', 'metal', 'm'
    • Specular: 'specular', 'spec', 's'
    • Specular F0: 'specularf0', 'f0'
    • Roughness: 'roughness', 'rough', 'r'
    • Glossiness: 'glossiness', 'glossness', 'gloss', 'g', 'glossy'
    • AO: 'ambient occlusion', 'ao', 'occlusion', 'lightmap', 'diffuseintensity'
    • Cavity: 'cavity'
    • Normal Map: 'normal', 'nrm', 'normalmap'
    • Bump Map: 'bump', 'bumpmap', 'heightmap'
    • Emission: 'emission', 'emit', 'emissive'
    • Opacity: 'transparency', 'transparent', 'opacity', 'mask', 'alpha'
    • Subsurface Scattering: 'scattering', 'subsurface'
    • Subsurface Translucency: 'translucency', 'thickness'
    • Clear Coat: 'clearcoat'
    • Clear Coat Roughness: 'clearcoat roughness'
    • Clear Coat Normal Map: 'clearcoat normal map'

    Troubleshooting

    • Make sure you include the image files with the upload, and the .MTL file when uploading .OBJ.
    • Make sure the path and file names linking the textures are correct.
    • Try uploading your textures manually in 3D settings.
    • If applying a texture does nothing, or seems to apply a solid color, this can indicate a UV-mapping problem.
    • 3D scans and models with baked lighting often look best in Shadeless mode.
    • Avoid spaces and special characters in your material, texture, and file names. Name everything with ASCII / UTF-8 compliant characters.
    • Avoid image sizes bigger than 8192×8192 pixels.
    • Avoid image file sizes bigger than 10MB.
    • Avoid color spaces like CMYK.

     For performance tips, see Viewer Performance.

    Filtering

    There are four options for texture filtering.

    • Trilinear: Usually the best choice, especially for large textures.
    • Nearest (mipmap): Can be useful for block textures like Minecraft blocks and pixel art with very small textures
    • Bilinear: Can be useful for masking and hiding texture seams
    • Nearest: Legacy, use Nearest (mipmap) instead.

    Color Formats

    Depending on the shader slot you're working with, you'll see different color encoding options under Format:

    • RGB: Red, Green, and Blue color channels
    • Alpha: Alpha transparency channel only
    • Luminance: R channel only

    By choosing the appropriate format, texture opacity can be encoded either as an alpha mask or by grayscale levels.

    UV Channels

    If you have more than one UV channel on a single material, you will see an additional interface option to switch between them.

    Sketchfab 3D model editor texture UV channels

    UV Offset and Tiling

    UV Offset and Tiling are not currently supported.

    Texture Wrap Modes

    Texture UV coordinates (u, v) map to surface ST coordinates (s, t). UV coordinate values can only range from (0, 0) to (1, 1), so there are several ways to wrap a surface with a texture. Mapping options can be changed with Wrap S and Wrap T:

    • Repeat: The texture is tiled (2.6 → 0.6)
    • Mirror: The texture is mirrored (1.2 → 0.8)
    • Clamp: Texture pixels outside the [0, 1] range will be clamped to the border of the texture

    Sketchfab 3D model editor texture UV channels S/T wrap repeat mirror clamp

     

    3rd Party Rendering Engines

    Proprietary renderers/shaders like V-Ray, and Mental Ray should have their lighting and textures baked for best results. The 3ds Max Exporter, for example, is able to bake materials and upload to Sketchfab automatically.

    KeyShot currently offers no baking features and very limited material encoding in supported formats (STL and OBJ). Keyshot users should prepare materials/textures in other software or use PBR mode in Sketchfab without textures.

    Related articles

    Comments

    96 comments

    Date Votes
    • James

      Hi @samplia,

      I'm afraid there has been no progress on supporting animated textures in the "regular" viewer, it can only be done with the Viewer API:

      https://sketchfab.com/developers/viewer

      https://sketchfab.com/developers/viewer/examples?sample=Video%20Texture

      For what it's worth, Twinmotion and Sketchfab are both part of Epic Games, and we are working on tighter integrations between the various tools (especially Quixel and Twinmotion). So, maybe we'll be able to handle such materials at some point.

      0
    • orfeasrodo

      Hey again @James,

      I see here https://help.sketchfab.com/hc/en-us/articles/360018381618-Texture-UV-Transformations

      that: UV transforms can be imported and exported via glTF

      But with the https://github.com/sketchfab/unity-plugin/releases/tag/1.2.1  when we Publish to Sketchfab the textures are not uploaded (understandable you only post the glTF) with the glTF file but also the material is not correct.

      When it finished uploading I saw in the 3Dsettings that the Emission was ON ( my materials had only a basecolor texture, normal map texture and some tiling/scale variable to check the UV Transforms, I am using HDRP/Lit materials.) and after I uploaded the textures and assigned them properly the  UV transforms was the default ones.

      So is it that the glTF the api is sending has no material info or is it a compatibility issue with HDRP?

      If the textures was in the zip the the api is posting would the textures be assigned properly with UV transforms ?

      Overall, you think I have better compatibility with glTF over obj + mtl ?

      (exporting models + materials + textures from unity, uploading to Sketchfab )

      If you have any documentation about the format of a glTF file or anything that can help me I would appreciate it.

      Thank you for your time.

      0
    • doneil

      @James

      Avoid material names with matching substrings, for example "handle" and "woodenhandle" in the same scene.

      How strict is this requirement? I ask because I often have matching substrings in material names to help organize my materials—for example, let’s say I have a scene containing a church and a house. I may want to have all my materials assigned to the church structure prefixed with “chu” and those assigned to the house structure prefixed with “hou,” e.g., chuRoof, chuDoor, houWindow. The prefixes also help distinguish between materials for analogous elements in both structures, e.g., chuDoor vs. houDoor.

      0
    • Parjapati.Alok

      Pls help me। Mujhe bhi video banana hai 3d me

      0
    • eng.costajunior

      É possível deixar o fundo transparente?

       

      0
    • James

      Yes, you can make the background transparent. Learn more here: https://help.sketchfab.com/hc/en-us/articles/203064198-Scene#background

      0

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