20.10.20265 min

Frosted glass in Corona: patterns with Decal

For a glass partition with frosted stripes, assign clear glass to the model and the frosted material to a Corona Decal object. An Opacity color mask defines the pattern. An additional decal with clear glass can keep a logo readable within the frosted area. The partition keeps its shared geometry.

Prepare clear and frosted glass

Create a Corona Physical Material in the Slate Material Editor and choose a glass preset. Assign it to the main partition. Check the glass without decals first: the interior behind it should remain visible, while the surface produces reflections.

Create a separate Physical Material using a frosted-glass preset for the sandblasted pattern. Prepare another clear-glass material for the logo, so its mask stays independent of the stripes.

In Physical Material, roughness affects both reflection and refraction. Increasing Roughness blurs both effects. If the material uses Glossiness mode, the direction is reversed; check the mode before transferring values.

Make the logo mask in Photoshop

Prepare an image with a white logo on a black background. White mask areas keep the material visible; black areas exclude it. Here, the logo material is clear glass, so the white shape creates clear areas over the frosted surface.

In Photoshop, merge the symbol and text layers, select their silhouette, and fill it with a solid color. Add a contrasting background and invert the image if needed. Before saving, check that it is a white shape on black, rather than a colored logo or the transparency checkerboard.

Load the finished mask as a Bitmap and connect it to Opacity color in the separate glass material. If the pattern is reversed, check the mask polarity before adjusting the projection further.

Black-and-white symbol and lettering mask in Photoshop. — Finished mask: a white symbol on a black background in Photoshop. 00:02:49

Place Corona Decal on the partition

Create a Corona Decal from the Corona object category. AutoGrid helps place the projection on the surface. Adjust its dimensions to the glass, then inspect it from the top: the projection must cover the intended part of the partition.

Assign the frosted material to the decal and start interactive rendering. Check a solid frosted area first. This separates material or placement problems from pattern problems.

The projection size and depth control its area of influence. If the effect does not reach the intended area, check the decal volume and its position relative to the glass. Exact values depend on your scene dimensions.

Add stripes with Checker

For a repeating pattern, connect a Checker map to Opacity color in the frosted material. The black-and-white pattern limits the areas where the decal replaces clear glass with frosted glass.

Change Tiling in the map coordinates and watch the rendered result. You can adjust repetition without modeling each stripe. Check the pattern from the final camera: very dense or narrow details may look different in a wide shot.

Checker suits regular patterns. For a specific symbol or lettering, use the prepared Bitmap mask.

Checker and Corona Physical Material nodes connected through Opacity color. — Checker connected to Opacity color in the frosted material. 00:05:29

Add a clear logo with a separate decal

Create an additional Corona Decal in the logo area. Assign clear glass with the prepared mask in Opacity color. The image scale and projection position determine where the clear letters and symbol appear.

Check its overlap with the frosted decal. The demonstration adjusts the second projection volume and evaluates the overlap. Do not treat a larger size as a universal priority setting across Corona versions: check overlapping decal order in your version and in the render.

If the lettering disappears, temporarily disable the neighboring decal and check the logo material separately. Restore the overall pattern and inspect the overlap again.

Stripes and a separate logo on the glass partition in the interactive render. 00:06:47

Check the result before the final render

Compare clear gaps, frosted stripes and the logo. Interior details should remain readable through the gaps and blur behind frosted areas. If frosting covers everything, first check the mask connection and contrast. If the pattern is misplaced, check the projection position and dimensions.

For a thin glass surface, Thin shell (no inside) differs from the material of a solid glass object. Choose it according to the geometry: Chaos documentation explains that a thin shell does not produce true refraction, while solid glass requires a different mode.

Questions and answers

Do I need to model every frosted stripe?

This method uses a shared glass surface, Corona Decal and a material mask. A Checker map controls stripe repetition.

Can I use my own design instead of Checker?

Yes. Prepare a black-and-white mask in Photoshop and connect the Bitmap to Opacity color in the relevant material. The logo in this setup uses a separate decal.

Technical documentation: Chaos: Corona Physical Material · Chaos: glass types and Thin shell