Materials

SketchUp materials map one-to-one to Rayscaper materials. Rayscaper materials offer a wider breadth of options to create beautiful visualizations. Every SketchUp material in your model has a corresponding Rayscaper material with the same name. Renaming the material in SketchUp will rename the related Rayscaper material.

When you create a new material in SketchUp, a corresponding Rayscaper material is made. The Rayscaper material will have the same color, texture, and opacity as the SketchUp material. This gives you a starting configuration in Rayscaper. Subsequent changes to the material are not synchronized to Rayscaper. The philosophy is that you create a more sophisticated material setup in Rayscaper and don’t want to destroy this setup with your changes from SketchUp. If you want to re-synchronize the changes from SketchUp, you can do this explicitly via the resync button. This overwrites the material configuration in Rayscaper.

How to resync the SketchUp material: Select the material (1), and click the resync button (2).

To correctly render your geometry in Rayscaper, every face in SketchUp must have a material painted on it. Using the default material won’t work. This material must be painted on the front face, not the back one. When a face does not have a material assigned to it, Rayscaper will try to use the material painted on the object that contains the face. When the face doesn’t have a material, it will render in clay color. So, clay-colored surfaces in the render are a warning sign that materials are not assigned in SketchUp.

Textures

We can only really talk about materials after discussing textures first. Textures are essential to get realistic-looking materials. All materials in Rayscaper are configured via input textures. Textures allow creators to vary the properties of the materials based on the surface position. For example, using image textures to make the material look like wood based on a wood grain image.

In Rayscaper, textures appear in two forms. First, as color inputs for materials—for example, each material has a base color. Second, as single values—for example, a material’s opacity is a single value. This will become clearer when we discuss the various texture types.

You can switch between texture types by clicking the arrow icon and then selecting a different texture type from the dropdown menu.

Changing the texture type via the dropdown menu.

Constant Texture

The simplest texture in Rayscaper is the constant texture. It’s either a constant color or a constant value. You can click the color in the user interface to display the color chooser. You can change a single value by sliding it.

Configuration of constant colors and values.

Image Texture

The texture you will likely use the most is the image texture. With image textures, you can vary a material property based on an image.

How does the render engine know which image pixel to apply where on the surface? For this, the render engine uses a technique called UV mapping. With UV mapping, every point on the surface has a two-dimensional coordinate value (e.g., (0.24, 0.54)), in addition to its three-dimensional coordinate. These two-dimensional coordinates are called UV-coordinates. The render engine uses these coordinates to map the surface position to the correct image pixel. SketchUp determines the UV mapping for every surface, but you can manipulate them in Rayscaper, as you will see later. For more information, look at this Wikipedia entry.

Mapping from 3D coordinates to pixel values via the UV-map. Source: Wikipedia.

Because image textures are so important, we made it easy in the UI to configure an image texture input for a material. You can configure the image texture by switching to the image texture type for the input via the dropdown menu, clicking on the icon after the input name, or dragging and dropping an image on this icon.

Different ways of creating an image texture. Either via the dropdown menu or the icon by clicking or dragging and dropping.

Image textures have various configuration options. We will go over them one by one.

The configuration widget for image textures.

Image Path: You can change the image file for a texture via the Open Image... button. If you edited the image in an external program, you can reload the image via the Reload Image button.

Wrap Mode: The wrap mode determines what happens for UV coordinates that fall outside the pixel boundaries of the image we use as a texture. Rayscaper supports the following wrap modes:

Black: Color values outside the pixel boundary are black, or zero for constant values.
Repeat (default): Repeats the image. This is how you create tiles of images. Note that the image must be _ seamless_, i.e., the left and right edges are symmetric, and the top and bottom edges of the image are symmetric. If the image is not seamless, you will see artifacts at the tile edges between repeated images.
Clamp: Clamps the outside value to the image’s pixel value at the edge.

Color Space: Configures the color space of the image. Rayscaper needs to know this to correctly convert the image to the linear color space used for rendering. The options are:

sRGB: The image uses the sRGB color space. This is typical for low-dynamic range image formats like PNG and JPEG. Rayscaper converts the image from sRGB to linear color space before rendering.
Linear: The image is already in linear RGB color space. This is typical for high-dynamic range formats like EXR and HDR. No conversion is needed.
Auto (default): Automatically detects the color space based on file format. Rayscaper assumes sRGB for low-dynamic range formats and linear for high-dynamic range formats. Normal maps are always treated as linear regardless of format.

Invert: Inverts each color in the texture.

No Invert
Invert

Texture Transformation: It’s possible to transform the texture in Rayscaper. This modifies the texture’s placement on the surface. We support the following transformations:

Rotation: Rotates the image around its center by the specified angle in degrees.
Scale: Scales the image in the X and Y directions.
Translate: Translates the image in the X and Y directions.
Shear: Shears the image in the X and Y directions.

The images below show the texture transformations:

Checker Texture

Checkerboards are classic textures in computer graphics—people have been rendering spheres on checkerboards since the early days of 3D graphics. Rayscaper includes a procedural checker texture.

An all-time classic in rendering, a glass sphere on a checkerboard.

The below image shows the configuration of the checks texture:

Configuration options for the checks texture.

Even Texture: The texture applied to the even squares of the checkerboard.

Odd Texture: The texture applied to the odd squares of the checkerboard.

Texture Mapping/UV Transformation: Controls the placement of the checkerboard on the surface by transforming the UV-coordinates. The exact meaning of each transformation is explained in the image texture section.

UV Texture

The UV texture is a utility texture that you can use to display the UV coordinates of your surface. This can help in debugging problems caused by invalid UV coordinates.

The red channel visualizes the U-coordinate, and the green channel visualizes the V-coordinate. Values are displayed in the 0–1 range, so negative UV coordinates appear black, as do coordinates exceeding 1. Here’s how to interpret some common coordinates:

(0, 0) black
(1, 0) pure red
(0, 1) pure green
(1, 1) pure yellow

UV texture applied to a cube.

The below image shows the configuration of the UV texture:

Configuration options for the UV texture.

Texture Mapping/UV Transformation: Transformation applied to the visualized UV coordinates. The exact meaning of each transformation is explained in the image texture section.

Mix Texture

The name says it all: you can mix two textures with the mix texture. This can be handy for creating complex textures based on simple input textures.

Mixing a leaf and noise texture.

The below image shows the configuration of the Mix texture:

Mixing texture configuration options.

Texture A: The first input texture.

Texture B: The second input texture.

Blend Amount: Controls the mix between textures A and B. A value of 0 uses only texture A, 1 uses only texture B, and 0.5 blends them equally.

Perlin Noise

The Perlin noise texture is procedural. This means that it calculates the noisy look of the texture at render time.

The below image shows the configuration options for the Perlin noise:

Perlin noise configuration options.

Type: Specifies the Perlin noise flavor to use. Currently, Rayscaper supports:

Fractal
Perlin
Turbulence

Color A: The first color/texture used in the noise calculation.

Color B: The second color/texture used in the noise calculation.

Frequency: The noise frequency controls the noise grain.

Roughness: Controls the roughness/smoothness of the noise.

Texture Mapping/Transformation: Controls how the noise is applied to the surface. Unlike other textures, noise uses a three-dimensional transformation.

The below images show a couple of noise variations generated by modifying the transformation.

Global UV Edit

Sometimes you want to position multiple textures at once with the same transformation. For this, you can use the Global UV Edit tool. You can activate the tool by selecting Global UV Edit in the Quick Edits menu.

Activating the Global UV Edit tool.

Once activated, every edit you make to the UV transformation will update all selected textures. The tool closes after clicking the Done button.

Global UV Edit tool.

Common Material Settings

Every material in Rayscaper shares four common properties: Color, Opacity, Normal Map, and Emission. These settings work identically across all material types.

Color

The base color of the material. You can set this to a constant color or use an image texture for more realistic results. For PBR workflows, this corresponds to the albedo or diffuse map.

Opacity

Opacity controls how opaque or transparent the material is. A value of 0 means fully transparent, and 1 means fully opaque.

Normal Map

Normal mapping is a technique to fake surface detail without adding geometry. It works by modifying the shading normals used in lighting calculations. A normal map encodes XYZ normal directions in the RGB channels of an image. The dominant Z direction gives normal maps their typical bluish color.

Example normal map.

With Normal Map
Without Normal Map

Normal map configuration options.

Normal Map Type: Enables or disables normal mapping.

Texture: The image texture used for normal mapping. The image must be a tangent-space normal map.

Flip Red: Inverts the red channel.

Flip Green: Inverts the green channel.

Swap Red and Green: Swaps the red and green channels. Useful when converting between DirectX and OpenGL normal map conventions.

Emission

Every material in Rayscaper can emit light. Rayscaper supports two emission modes: Color and Temperature.

Color Emission

Color emission emits a constant color in all directions. By default, emission only occurs on the front face of the surface.

Configuration options for color emission.

Enable Emission: Turns emission on or off.

Color: The emission color.

Power: The intensity of the emitted light in watts.

Two Sided: Emits light from both sides of the surface.

Fake Emitter: Makes the material appear bright like an emitter, but the geometry won’t actually light the scene. This option can reduce render times.

Fake Emission On
Fake Emission Off

Temperature Emission

Temperature emission (blackbody emission) simulates physically accurate light emission based on temperature. Lower temperatures produce red/orange light, while higher temperatures produce blue/white light. The sun and stars are examples of blackbody emitters.

Configuration options for temperature emission.

Enable Emission: Turns emission on or off.

Temperature: The blackbody temperature in Kelvin (K).

Power: The intensity of the emitted light in watts.

Two Sided: Emits light from both sides of the surface.

Fake Emitter: Makes the material appear bright like an emitter, but the geometry won’t actually light the scene.

Material Types

Coated Material

The coated material models a diffuse base layer with a glossy coating. Use this material to create laminated flooring, glossy paint, car paint, and similar surfaces.

Configuration options for the coated material.

Coating Color: The reflection color of the glossy top coating.

Roughness: Controls the blurriness of reflections in the coating layer. A value of 0 produces sharp reflections, while higher values create increasingly blurry reflections.

Diffuse Material

The diffuse material is the simplest material in Rayscaper. It models matte, non-shiny surfaces that scatter light equally in all directions. This material has no additional properties beyond the common settings.

Diffuse material configuration options.

Example of a red diffuse material.

Glass Material

The glass material models transparent dielectric (non-conducting) materials like glass, water, crystal, and quartz.

Glass material configuration options.

Index of Refraction (IOR): Controls how much light bends when passing through the material.

The table below shows the IORs of some common materials:

Material	Index of Refraction
Air	1.0
Ice	1.31
Water	1.33
Glass	1.5 to 1.7
Ruby	1.77
Sapphire	1.77
Crystal	2.0
Diamond	2.42

Roughness: Controls the surface roughness. Lower values create a smoother surface, while higher values create a rougher, more frosted appearance.

Thin: Treats the glass as a thin sheet without internal refraction. Use this option when glass is modeled as single planes. Roughness is ignored for thin glass. This mode can look incorrect on curved surfaces due to the lack of refraction.

Thin Glass - Off
Thin Glass - On

Transparent Shadows: Makes the glass transparent to shadow rays. This can improve the rendering of indoor scenes by allowing direct light to pass through glass surfaces. Also known as architectural glass.

The image below shows a metal inner cube surrounded by a glass outer cube. Notice how there’s more light in the inner cube when turning on the transparent shadows option.

Glass Transparent Shadows Off
Glass Transparent Shadows On

Metal Material

The metal material creates physically accurate metallic surfaces. The appearance of different metals is determined by their index of refraction (IOR) and absorption coefficients. You can select from presets or enter custom values.

Configuration options for the metal material.

Metal Presets: Select from common metals like gold, silver, copper, etc. The preset automatically sets the correct IOR and absorption coefficient values.

Metallic IOR: The index of refraction for the metal (RGB values).

Absorption Coefficient: Controls how the metal absorbs light at different wavelengths (RGB values).

The table below shows values for common metals:

Metal	Metallic IOR	Absorption Coefficient
Aluminium (Al)	(1.35, 0.97, 0.62)	(7.47, 6.40, 5.30)
Brass (Cu-Zn)	(0.44, 0.53, 1.09)	(3.70, 2.77, 1.83)
Copper (Cu)	(0.27, 0.68, 1.32)	(3.61, 2.62, 2.29)
Gold (Au)	(0.18, 0.42, 1.37)	(3.42, 2.35, 1.77)
Iron (Fe)	(2.91, 2.95, 2.58)	(3.09, 2.93, 2.77)
Nickel (Ni)	(1.99, 1.92, 1.73)	(4.21, 3.62, 2.94)
Platinum (Pt)	(2.38, 2.08, 1.85)	(4.27, 3.72, 3.14)
Silver (Ag)	(0.16, 0.15, 0.14)	(3.93, 3.19, 2.38)
Titanium (Ti)	(2.74, 2.54, 2.27)	(3.81, 3.43, 3.04)

Roughness: Controls the surface roughness. A value of 0 creates a mirror-like finish, while higher values produce increasingly blurry reflections.

Mirror Material

The mirror material creates a perfectly smooth, reflective surface. The Color property tints the reflection.

Configuration options for the mirror material.

PBR Material

The PBR material is Rayscaper’s most versatile material. It uses Physically Based Rendering principles and can emulate a wide range of real-world materials. In other render engines, this is often called the principled material.

Layers for the PBR material.

The PBR material uses a layered approach. The base layer blends between metallic and diffuse reflection. On top sits an optional glossy coating and a sheen layer for cloth. The material also supports transmission for translucent effects.

Configuration options for the PBR material.

Metallic: Controls the metallic appearance. A value of 0 creates a dielectric (non-metal) surface, while 1 creates a fully metallic surface. Use a PBR metal map for complex materials.

Roughness: Controls the roughness of the surface. Zero means perfectly smooth and one means very rough. Highlights become blurrier with increased roughness. A PBR roughness map can be used as the input.

Index of Refraction: Index of refraction (IOR) of the material. This controls at which angles reflection and refraction occur on the material surface.

$Index of Refraction 1$

Anisotropic: Controls the amount of anisotropy for specular highlights. Higher values elongate the highlights in the tangent direction.

Sheen: Sheen (fuzz) can be used to model cloth. This subtle effect creates a white shimmer near the edges and folds of the cloth, caused by dust particles and small fibers.

Transmission: Controls the amount of light that passes through the material. 0 makes the material completely opaque, and 1 makes it fully transmissive like glass. This is useful for creating translucent materials.

Coating Strength: Adds a coating layer on your material, such as adding varnish on floors. 0 turns off the coating layer, and 1 configures it at full strength. For the best effect, you should apply the coating layer to a rough surface.

Coating Roughness: Controls the roughness of the coating layer. A value of zero produces sharp highlights, and a value of one produces blurry highlights.

Plastic Material

The plastic material models a diffuse base layer with a glossy specular layer on top. It’s similar to the coated material but allows a colored specular reflection. Use this material for plastics, glossy painted surfaces, or any material where the specular highlight has a distinct color.

Glossy Color: The color of the glossy specular reflection layer.

Roughness: Controls the roughness of the glossy layer. A value of 0 produces sharp highlights, while higher values create increasingly blurry highlights.

Index of Refraction (IOR): Controls the intensity of specular reflections at different viewing angles. Typical values for plastic are around 1.5.