Marble
Gloss and veins
Give the veins their own finish, then set how glossy the whole stone is, in the gloss units a gloss meter reads.
Matelume Guide. Upcoming features are marked separately.
Two Craft steps set how your marble reflects light. Roughness by selection gives the veins a finish of their own. How glossy then sets the finish of the whole stone. An image cannot show gloss, so both are choices you make, not readings from the picture: the gloss never comes from the image's colours.
Roughness by selection
The veins are selected automatically and softly: dark veins, light veins and coloured threads, each with soft edges. Instead of being raised, the selected veins get their own gloss.
Picking the veins by hand is not available yet, so clicking the image does not change the selection.
Under What the selection does, five cards:
| Option | What the veins do |
|---|---|
| Veins slightly duller | A little duller than the ground: about 97 and 77 GU when polished. Recommended, and already selected |
| Veins glossier | They polish better than the ground |
| No vein effect | One even polish everywhere: the veins change nothing |
| Honed | A honed stone, about 14 GU, the veins a touch duller |
| Strong contrast | The veins clearly matte, like soft minerals or resin |
Each option comes with the finish it was made at. Picking an option sets How glossy to that finish, and you can change it again in the next step; the veins keep the change you chose here.
The picture shows two panels: the selection (the veins in colour, the rest dimmed) and the roughness map (dark is glossy). Its labels give the share of the slab the veins cover and the roughness of the ground and of the veins.
How glossy
How glossy sets the overall finish in gloss units (GU), the way a gloss meter reads stone. Higher means a glossier stone. Under The finish, five cards:
| Finish | Gloss |
|---|---|
| Mirror polish | 97 GU, recommended for polished marble |
| Polished | 82 GU |
| Satin | 45 GU |
| Honed | 14 GU |
| Matte | 5 GU |
The Gloss slider goes from 5 to 102 GU for any value in between. Its value line shows the GU, the nearest finish's name and the roughness it becomes. While you drag, the 3D view changes live; let go and the maps are made again.
Polished marble reads about 91 to 97 GU, honed about 14. If your supplier measured your slab with a gloss meter, set that reading on the slider: Matelume turns it into roughness for you. The veins keep the change you chose in Roughness by selection.
The picture shows your marble and its roughness map, labelled with the gloss of the ground and of the veins in GU.
In the export
Your finish goes into the Roughness map (and the Glossiness map, when your programs use one). The .json records the finish's name, its gloss in GU and the roughness of the ground and the veins. The vein selection is exported too, as the vein mask, so you can build your own changes on it. The how-to sheet for each program says how to connect the roughness, for example to V-Ray's reflection glossiness with its roughness option on.
Tip: Judge the finish on the Sphere with Light on. A glossy stone shows a sharp reflection; a honed one spreads it into a soft sheen.