Coming from Thea Render

If you render with Thea for SketchUp, this guide shows where everything you know from it lives in Rayscaper: the material presets and the layered editors, the Thea lights, the sun, sky and IBL, the Darkroom’s display settings and the render engines.

A lot will feel familiar. Like Thea, Rayscaper is a physically based renderer inside SketchUp: it starts from the colors and textures of your SketchUp materials, takes the sun from SketchUp’s shadow settings, places lights as SketchUp components, and lets you click a surface in the render to edit its material. The differences are in how much you have to decide before the first good image:

One way of rendering. There is no engine to pick (Presto, Nitro or an unbiased mode) and no switch between interactive and production rendering. The render in the Rayscaper window is the final render: it updates while you model, orbit and change settings, and gets cleaner the longer you leave it alone. You save it when it’s clean.
Fewer settings. A material is one of five types, each with presets and finishes, and the rest of its settings sit in a collapsed Advanced section. Lights start as real lamps, in lumen.
A photographic camera without the photographic homework. Exposure is one value in EV, or automatic, instead of ISO, shutter speed and f-number.

The workflow at a glance

In Thea for SketchUp you…	In Rayscaper you…
opened the Thea Tool window and the rendering window (Darkroom)	click Start Render: one window with the render and the Scene Editor next to it
chose an engine and started interactive or production rendering	render right away: there is one render method, see Rendering
picked a material with the Thea cursor or the crosshair in the render, and chose a preset in the Material tab	turn on Material Pick (Ctrl+M), click a surface in the render and choose a material type and finish
created a point, spot, IES or projector light from the Lights tab	pick a light tool on the Rayscaper toolbar and place it in SketchUp
set up the sun, sky and IBL in the Environment tab	choose a Sky, HDRI or Color environment
set the exposure, tone mapping and effects in the Display tab	use the Post Processing section, live on the render
set the channels, the animation and the batch in their tabs	render passes, scenes and animations from the File menu
dragged materials, models and skies from the content browser	drag materials and HDRIs from the Asset Manager onto the render

Your first render

Install Rayscaper next to Thea, and open your model. Both are SketchUp extensions and don’t get in each other’s way.
Click Start Render on the Rayscaper toolbar. The Rayscaper window opens and renders the current SketchUp view. Every SketchUp material gets a Rayscaper material with the same color, texture and opacity. Thea’s own material settings aren’t read, so this is where you start from.
Set up the light outside. A new model starts with Rayscaper’s sky, whose sun follows SketchUp’s Shadows panel, like Thea’s sun does by default. For other light, change the Environment or drag an HDRI from the Asset Manager onto the render.
Give the key materials a type: make the windows Glass, the fixtures Metal, and pick a finish for the rest. See Materials.
Place your lamps again with Rayscaper’s light tools, see Lights. Thea’s lights don’t light a Rayscaper render.
Save the render with File > Save… (Ctrl+S). Denoise on the toolbar is on for a new model and removes the last grain.

Rayscaper saves its settings in the model, next to Thea’s, so the next time you open it, it renders the same way. For a guided first render, watch the Quick Start video.

Materials

Thea for SketchUp has three ways to edit a material: the Presets, the layered Presto editor and the PBR Nitro editor. Rayscaper has one editor, closest to a Thea preset: you choose a material type, the color and texture come from SketchUp, and a Finish or preset sets the rest. Every setting a preset hides is still there, in the Advanced section of the type. Turn on Material Pick in the render window and click a surface, like with Thea’s crosshair, to open its material in the Materials section of the Scene Editor.

Thea's layered material editor with a Coating and a Basic layer — Thea Render

Rayscaper's Materials section with a Standard material — Rayscaper

A metallic paint in Thea’s layered editor, a Coating layer on a Basic layer, and Rayscaper’s Materials section: a material type, a finish and a few settings.

Thea	Rayscaper material	Notes
Preset: Default	Standard	Every new material is Standard with the Satin finish. Pick Matte for plaster and raw concrete.
Nitro: Standard	Standard	Both are metallic/roughness PBR materials, so the same color, roughness, metalness and normal maps fit.
Preset: Lacquer, Nitro or Presto Coating	Standard, Lacquered finish	A clear coat on a satin base. Tune the coat under Advanced > Coating.
Preset: Ceramic	Standard, Glossy or Lacquered finish
Preset: Mirror	Standard, Mirror finish
Preset: Metal, Colored Metal	Metal	Pick the metal (aluminium, chrome, copper, gold, brass, …); its color is measured. Raise Roughness for brushed metal, and Anisotropy under Advanced.
Preset: Car Paint	Car Paint	A base coat with metallic flakes under a clear coat.
Preset: Glass	Glass	For objects with thickness: bottles, glasses, aquariums.
Preset: Thin Glass, Nitro: Thin film	Glass with Thin on	For window panes modeled as a single face.
Preset: Thin Translucent	Standard, Sheer Fabric finish	Or set the Translucency of any Standard material, for lampshades and leaves.
Water materials	Water	For pools and ponds, with presets and a depth tint. Water in a glass is Glass with an IOR of 1.33.
Preset: Emitter, Emittance component	Any type, with Emission	Its Power is in Watts, its color a color or a temperature. Fake Emission glows without lighting the scene.
Clipping, Opacity	Opacity	Use the alpha channel of a PNG to cut out leaves and fences.

A few things work differently:

Bump and displacement. Rayscaper uses normal maps for surface detail, see Normal Map. Most texture sites offer a normal map next to the color texture. Bump (height) maps and displacement aren’t supported.
Layers. Instead of stacking Basic, Glossy, SSS and Coating layers with weights, a Standard material has one layer for each of coating, sheen, translucency, transmission and anisotropy under Advanced. A mix of two materials across a surface is a Mix texture.
Procedurals. Thea’s procedural textures are Noise, Checkerboard and Mix textures, which work in every setting of a material.
Ready-made materials. The content browser and Thea’s online repository are the Asset Manager: Poly Haven’s scanned materials, Rayscaper’s own materials (paints, car paints, ceramics, fabrics, metals, gems, …) and the materials you save yourself. Drag one onto a surface in the render. Thea’s .mat.thea files can’t be loaded.
Changes in SketchUp. Once Rayscaper has created a material, later changes to the SketchUp material don’t overwrite your Rayscaper settings. Click Reload to take them over, see Working with SketchUp Materials.
Not available: subsurface scattering through thick objects (Thea’s SSS for wax, skin and marble), media and the Cloud preset, dispersion (the Abbe number), back-face materials, the shadow catcher, fur and the random color texture.

Lights

Thea’s lights are SketchUp components that you create from the Lights tab with two clicks, the light and its target. Rayscaper’s lights are SketchUp components too, with a tool per type on the Rayscaper toolbar: click a reference point, then the light’s position, then (for all but the point light) where it points. SketchUp’s inferences, arrow-key axis locks and the Measurements box all work. See How Light Placement Works. Rayscaper doesn’t read Thea’s light components, so place your lamps again. If the icons of Thea’s lights show up in the render, put them on a tag and hide it.

Rayscaper's Spotlight settings with the IES patterns — Rayscaper

Thea’s Lights tab with a point light, and Rayscaper’s Spotlight settings, here with a built-in IES pattern.

Thea light	Rayscaper light
Point light (omni)	Point Light
Spot light	Spotlight, with Distribution set to Cone
IES light	Spotlight, with Distribution set to IES. Import your `.ies` files with Import custom IES…, or use a built-in pattern.
Projector light	No counterpart. Use a Spotlight, or an Area Light for soft, even light.
Emitter material on a face	An Area Light, or a material with Emission. An area light renders with less noise.
Sun	The sun of the sky, and optionally a Directional Light that follows SketchUp’s sun too.

How the settings translate:

Power in lumen carries over: Rayscaper’s point lights, spotlights and area lights take their intensity in lumen too, and its presets (a 60 W bulb, an LED downlight, an LED panel, the sun) give you real values to start from. For a Thea light in Watts, multiply the Watts by its Efficacy to get its lumen: 100 W at 10 lm/W is 1000 lm. See Intensity Units.
Temperature (K) is the same: set Color to a temperature in Kelvin. 2700-3000 K is the warm white of most interior lights.
Soft shadow radius is Radius: a larger light gives softer shadows. A few centimeters is realistic for a bulb.
Hot spot and Fall off become Cone Angle (half the beam width) and Falloff (how soft the edge is, 0 to 1).
Attenuation has no setting: every light falls off with the inverse square of the distance, like real light.
Shadow and Evaluation have no counterpart: every Rayscaper light casts physically correct shadows and lights every material.
Relight has no counterpart, but changing a light takes effect in the live render at once. Keep the versions you like in the render history to compare them.
The shape of a selected light shows in the SketchUp viewport while Rayscaper renders: the cone of a spotlight, the radius of a point light. See Seeing a Light’s Shape in SketchUp.

Environment

Thea’s Environment tab is the Environment section of Rayscaper’s Scene Editor. See Environments.

Thea's IBL tab with the Illumination, Background, Reflection and Refraction slots — Thea Render

Thea’s IBL with its four image slots, and Rayscaper’s Environment section with the sky and its sun.

Thea	Rayscaper
Physical sky and sun	Sky, with a sun that follows SketchUp’s Shadows panel. Instead of the turbidity, it has a Haze slider.
Manual sun, or Use SketchUp Sun position off	Turn off Extensions > Rayscaper > Use SketchUp Sun for Sky and set Sun Elevation and Sun Rotation.
Sky presets (`.sky.thea`)	The presets of the sky, from a clear midday to a night.
IBL	HDRI, from an `.hdr` or `.exr` file, with Power and Rotation. The Asset Manager has the whole Poly Haven HDRI library. One image lights the scene and is the background, its reflections and refractions; Thea’s separate Background, Reflection and Refraction slots have no counterpart.
IBL with a color	Color.
Ground plane	Ground fills the view below the horizon. To catch shadows and reflections, model a ground surface.
Background removed, for compositing	Turn on Transparent: the environment still lights the scene, the background of the saved PNG is transparent.
Global medium, fog	Not supported.

Rendering

Thea makes you choose first: Presto or Nitro, interactive or production, and the tracing depth, time limit and passes of the engine. Rayscaper has one way of rendering, physically based global illumination, and it handles interiors, exteriors, sunlight, IES lights and emitting materials alike.

Rayscaper's Render section with the samples per pixel — Rayscaper

The settings of Thea’s Presto engine, and Rayscaper’s Render section: one method, rendering until it reaches the samples per pixel.

Engines and devices. There is no engine to choose. Rayscaper renders on the CPU, or on an NVIDIA GPU that you turn on in File > Settings…; on a Mac it renders on the GPU.
Interactive and production rendering are the same render. It runs until it reaches the Samples per Pixel you set (1024 by default), like Thea’s pass limit, and you can save it at any moment before that. With Denoise on, a render is often clean after a few hundred samples. See Samples per Pixel.
Tracing depth, diffuse depth and clamp level are the Diffuse, Reflection and Transmission Bounces, Transparent Layers and Highlight Clamp under Advanced. The Quality presets set them for you; raise only what a scene needs.
Interactive rendering in the SketchUp view isn’t needed: the Rayscaper window follows the SketchUp camera, so you frame the shot in SketchUp and see the render next to it. Click Lock Camera on the Rayscaper toolbar to keep the shot while you look around. While Rayscaper renders, an orange rectangle in the SketchUp view shows what’s in the render, with an optional composition guide like Thea’s rule of thirds.
Region rendering isn’t available: zoom in on the render window to judge the details.
Network rendering (Thea Node) isn’t available: Rayscaper renders on one computer.

Camera

Thea’s camera tab is the Camera section of the Scene Editor. See Cameras.

Thea	Rayscaper
Resolution, aspect ratio	Resolution
Depth of field: f-number or sharpness	Depth of Field: Blurriness sets the amount of blur
Auto focus, focus distance with Set	Autofocus, or Focal Distance with Camera Focus Pick (Ctrl+F): click what should be sharp
Standard projection, perspective or parallel	Perspective and Orthographic
Spherical projection	Panoramic, see the 360° Panoramas guide
Z-clipping, near distance	Near Clip Depth, or Near Clip Depth Pick (Ctrl+J) to click the distance in the render
Section cuts	Not rendered yet. Use Near Clip Depth to look into a room, or hide the walls in front with a SketchUp tag.
Cylindrical projection, stereoscopic rendering, motion blur	Not available.

Post processing

Thea’s Display settings are the Post Processing section, and like the Darkroom they work on the high-dynamic-range render, so you can change them after the render is done without rendering again. See Post Processing.

Thea's Display Settings with ISO, shutter and f-number and the exposure presets — Thea Render

Thea’s exposure with ISO, shutter and f-number, and Rayscaper’s Post Processing section.

Thea	Rayscaper
ISO, shutter speed and f-number	Exposure in EV stops, or Auto Exposure, which is on for a new model and keeps the image readable while you change the lights
Standard and Filmic tone mapping, highlights and shadows	Tone Mapping: PBR Neutral, ACES Filmic, Filmic and more, and Contrast under Color
White balance	Temperature and Tint under Color
Vignetting	Vignette under Lens Effects
Glare	Bloom & Glare
NVIDIA and Intel denoisers	AI Denoise

Channels, animation and batch rendering

Channels. Rayscaper’s passes are the diagnostic render methods: Albedo, Ambient Occlusion, Geometric and Shading Normals, Material ID, Object ID and more. File > Render Scenes… saves them next to every render, see Passes. With a license, save the render as an HDR EXR for compositing.
Batch rendering is File > Render Scenes…: it renders the SketchUp scenes you check one after the other, each with its own tags, hidden objects, shadows and camera, and names each image after its scene. See Render Several Scenes.
Animation: Rayscaper renders animations from your SketchUp scenes, including the sun moving between scenes, and on Windows encodes the frames into a video. See the Animation Guide. It also renders the clips of Fredo6 Animator.
Proxies and scattering: Rayscaper has no proxies. Its Scatter covers terrain with grass, plants and trees, which render in full while SketchUp shows a light preview, and it renders Skatter compositions like Thea does.

Licensing

Thea for SketchUp is a lease, renewed every year or every three years. A Rayscaper license is a one-time payment for a perpetual license, with a year of updates, and it keeps working after that. The free version has no time limit: its renders inside SketchUp are limited to 1280 pixels on the longest edge, carry a watermark and can’t be used commercially, so you can try Rayscaper on your own projects before you buy. See the Licensing FAQ, and Rayscaper vs Thea Render for a side-by-side comparison.

Missing something you relied on in Thea? Let us know, it helps us decide what to build next.

Credits

The Thea for SketchUp screenshots come from the Thea for SketchUp v3 documentation, as archived by the Internet Archive. Thea Render is a product of Altair, part of Siemens.