Please use only standard BlenderKit previews for materials, Ideally only the Sphere preview. Only exception from this rule are materials like fire or similar effects. Sometimes, the thumbnails are rerendered during validation with the internal thumbnailer.
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UV maps names shouldn't be included in the material
UV maps names shouldn't be included in the material when you upload it.
Material bump intensity shouldn't be too strong
If you overdo bump intensity in Blender, you can get not only unrealistic look, but also shading artefacts.
DirectX normal map
Your normal maps don't match the OpenGL standard. The material will not look correct after being downloaded from the BlenderKit.
How to name and describe your assets?
How to improve the names and descriptions of assets and get better results on search engines
The nodes are organized in a confusing manner. This may cause inconvenience to BlenderKit users.
material Subsurface scattering radius
Subdivision surface scattering radius in Blender is in metric units and should rarely be over 0.05
Wood mapping on model
The wood should always be mapped with the grain oriented parallel to the longer side of the wooden part, then the material in the BlenderKit database will look great.
Plant leaves with the alpha channel overlapping
Leaves with the alpha channel overlap, this can lead to an unrealistic rendering of the plant.
Model Topology Issues
There are topology issues in this model, like double/overlapping faces, double vertices, non-manifold faces, subdivision surface artifacts, or similar.
Wrong meshes or missing parts
Some parts seem to be missing, for BlenderKit uploads, be sure everything is parented to a single parent and not to include (unparent) any extra hidden meshes.
Improve materials on Model
There are some things to improve in your materials. Please study how to correctly use Cycles / EEVEE material systems to reach a better result.
Why applying scale (and rotation) matters
So many reasons to apply scale whenever you can in Blender 3D!
Model unrealistic shape
The shape/proportions of the of the object aren't realistic. Check reference pictures to study more the real shape of this object.
How to add translucency to leaves in Blender?
In the video tutorial, you will learn how to correctly set up leaves translucency.