The Corona Physical Material

Our design goal for the Corona Physical Material was to make it physically based and full realistic, yet keep it intuitive, flexible, and easy to set up.

You won’t find yourself having to tweak unnecessary sampling values and other confusing parameters, and can instead focus on the physical parameters that determine the look of a material, and you also won’t have to choose between 10 or 20 different material types – you can pretty much do it all using the single Corona Physical Material.

Features and technical details

Material Preview

Material previewing uses the same rendering engine as the final frame rendering. The default 3ds Max or Cinema 4D material preview scene is replaced with a custom, more representative Corona scene, so you get a genuine “What You See Is What You Get” material editor. The example below shows the material preview on the left, and the material in a rendered scene on the right:

Displacement

Chaos Corona's 2.5D Displacement lets you achieve detailed and accurate displacement while still optimizing parsing times and memory usage.

You can also control how displacement is handled when using a Layered Material, choosing between Blend All Layers (default), Only from base, or Add all layers.

Volumetrics and Subsurface Scattering

Chaos Corona also features a powerful approach to Volumetrics and Subsurface Scattering.

Fully ray traced solution

Historically, there were many algorithms for volumetric rendering, most of which relied on interpolation, fakes, and heavy bias to compute the result. Fortunately with modern CPUs in combination with our research, we have been able to ditch all of these outdated options and go straight for the most accurate, 100% ray traced solution. Even we were surprised by how fast the unbiased, un–interpolated solution could be!

Dedicated skin shader

Skin is one of the most complex materials to render, with many unique properties that cannot be covered in an all–purpose shader. The new CoronaSkinMtl shader makes it easy to control and adjust the look of the skin, and renders fast and efficiently with realistic results.

Even if you have never tried rendering realistic skin before, you’ll find it easy to use and will get great results with the default settings.

True 3D volume materials with “Inside Volume” mode

The Corona Volume Material offers an “Inside Volume” mode for true 3D volumetric materials. For example, by using a 3D noise map, you can have fog that varies in density in true 3D throughout the scene. Combined with the Corona Distance map, the possibilities are endless!

The example below compares the “On Surface” mode with the “Inside Volume” mode:

Fire, smoke, water, and more

Chaos Corona is compatible with most features of Chaos Phoenix, letting you use its simulations directly in 3ds Max – for example, a Phoenix explosion as the one shown below:

The equivalent of Chaos Phoenix for Cinema 4D users would be Maxon’s built-in simulation system called Pyro. You can now add an extra layer of action to your scenes with fire, smoke, and other Pyro simulations directly in Corona for Cinema 4D.

In both 3ds Max and Cinema 4D, you can also load and render the industry–standard OpenVDB format using the Corona Volume Grid object. This allows you to work with the results of simulations exported from Blender, Houdini, Chaos Phoenix, and more. The material settings in the Corona Volume Grid let you achieve a range of different looks and effects, even from the same OpenVDB data:

Dedicated hair shader

You can’t have a great skin shader without also having a great hair shader! Chaos Corona’s dedicated hair shader keeps with our philosophy of delivering physical realistic results, fast rendering, and a simple UI. Once again, even if you have never rendered hair or fur before, you will get great results even from the defaults.

Chaos Corona also supports native 3ds Max hair and fur, and Ornatrix and Hair Farm, so that the Hair shader will work for you, whatever plugin you use.

Bump Converter

By default, 3ds Max treats bump maps differently, so that some maps do not work as inputs to bump mapping. The Corona Bump Converter resolves this, allowing you to use any map as an input to the bump map channel in a shader. It also lets you use the 3ds Max native Output to apply adjustments to your bump map and get the results you would expect.

Corona Tile Map

Easily create stunning bathrooms, kitchens, walls, and floors with procedural tiles thanks to Corona Tile Map. You can now use bitmaps or procedural maps to define the colors of the tiles and repeat, randomize, or even tessellate an image onto the tiles, depending on your needs.

Many maps to choose from

Chaos Corona comes with many useful maps that you will soon find indispensable, such as Ambient Occlusion, Mapping randomization, Multimap, Triplanar mapping, Edge Map/Shader, and more. We’ll take a look at a few of them:

Curvature Map

Adding wear and tear or dirt into the nooks and crannies of an object is made easier thanks to the Curvature map. Here is an example:

Mapping Randomizer

This flexible map has two main functions. First, it lets you randomize the UVW positioning, rotation, and scaling of a texture across different instances, objects, material ids, etc.

Second, it lets you randomize UVW positioning, rotation, and scaling in just one object by dividing the UVW space into a series of tiles. This lets you avoid unwanted repetition and patterning which can be seen even with seamless textures when they are scaled to fit large surfaces such as floors, walls, ground surfaces, etc. It even works for procedural maps too, as seen in the image above.

Corona Distance Map

This flexible map can be used with Corona Scatter to easily achieve effects like keeping paths, roads, etc., clear of plants and trees. It can also be used for creative effects, like adjusting materials based on distance, creating ripples around objects in water, causing objects to glow as they approach each other, and more. It really is only limited by your creativity!

In the example below, the ground (with water included) and log were brought over from Quixel Megascans. The “Corona Distance map disabled” image looks a little unnatural, as the water appears completely still.

By using the Corona Distance Map to add extra displacement around the log, blended with the original displacement from Megascans, we can give the effect of ripples specifically around the log. Best of all, since this is procedural, if you move, scale, or rotate the log object in the scene, the displacement effect will update automatically.

Edge Map/Shader

Easily apply effects like weathering and staining to the edges of objects with Edge Map/Shader. This is particularly useful for objects with no thickness like leaves, photos, maps, paper, etc. The new Edge Map/Shader creates a color gradient based on how far away a point is from a geometric edge.

Material Overrides

For quick tests, or even for debugging a scene, it can be useful to override the materials with one simple material. This is easy to set up in Corona, with options that let you leave some materials (such as portals, glass, or light materials) unaffected by the override, in both 3ds Max and Cinema 4D.