Surface Imperfections – Volume 1
David Gruwiers premium collection of 50+ tiled textures of scratches, specs, smudges, fingerprints, dried water deposits, hairs and dust is finally here!
Exceptional for shading realistic up-close detail, the maps also works as general purpose natural grunge maps.
The texture maps are delivered in 4096×4096 16bit TIFF format, and there’s a 2k and 4k 8bit version included for more lightweight work.
The raw, unprocessed 8K+ full color scans are also included as an optional download (These constitute a useful texture library in and of themselves)
How to use them:
- As glossiness or anisotropy maps, to add realistic surface imperfections to reflective surfaces such as glass, metal and plastic
- Bump maps, for something more organic and natural than simple noise
- Extra detail on windows, monitors, mirrors and other surfaces that require that extra glint of realism
- Overlays on lens flares and glare in compositing, to emulate a dirty lens (the raw scans are especially suited for this)
- Mask and overlays to introduce interesting variation in any stage of shading or compositing
- Source material for alphas/brushes and for texture painting.
How were they made?
The textures were made by scanning various glass, metal, plastic and other surfaces in a photo/film scanner. The scans were converted to greyscale, manually tiled in Photoshop, then scaled down to 4k. This was all done in 16bit to preserve extra color information when converting and down-scaling the bitmaps. Extreme care was taken during the tiling process as David knew Grant would be working with the maps in future courses.
Here are some pointers and tips on using these textures, based on David’s experiences using them for 3D and composition work:
Depending on the render engine and shader, you might need to invert the maps. For example, if your render engine uses a glossiness value (like Vray) instead of a roughness value (like Arnold), you want to invert the fingerprint maps so that fingerprints show up as black on white.
Keep this in mind when working creatively with materials as well.
For example, polished metal might need scratches that appear rougher and less glossy than the surrounding material. But a sanded, matte metal finish might look better with an inverted map, so that the scratches are more glossy.
Try using the maps as bump detail. You can get some interesting looks, for example creating the appearance of paint with trapped pencil hairs and sand grains grains, by using the specs/hair textures
Adjust textures inside your render engine
Don’t be afraid to liberally use remap nodes, outputs, filters or your software’s equivilant value mapping or color correction feature to control the contrast and black/white points. I often use one node to invert the map if needed, one to control the contrast curve of the texture, then a last one to remap the black and white points to whatever glossiness values I need.
Use a blend material or similar to create multiple layers of reflections. For example, for a realistic glossy surface, you generally want one layer of mostly clean, glossy reflection, then another layer of rough, dirty reflections.
You can also try blending the whole material with a diffuse material using the dried water desposit maps as masks.
The scans are between 10-15 cm wide in real world units, but many of the textures are generic enough to work on much larger scales. I’ve used them on everything from tiny toy trains, to cars and even a gigantic spaceship and a moon landscape.
Try using the fingerprint textures as anisotropy rotation/orientation maps instead of glossiness, as this more accurately emulates how thin layers of fingerprints and grease behave on glossy surfaces. This becomes particularly obvious when the camera moves and animates.
This also works well for velour, suede leather and similar. Just remember to crank the contrast of the texture to fill out the entire value range.