Allura GPU Renderer - Overview

Allura GPU for SketchUp - Powered by NVIDIA Iray® is a plugin renderer developed by Render Plus, using NVIDIA Iray+ from Lightworks , that creates physically accurate renderings by tracing light paths. It unleashes the full power of Iray's interactivity and scalability with an easy-to-use, intuitive workflow that maximizes productivity by providing immediate visual feedback during scene development.

Bedroom Interior rendered with IRay


Image: Bedroom Interior Rendered in Iray for 3ds Max

This document describes the concepts and features in the plug-in, as well as help and advice on how to use Iray for 3ds Max. This guide assumes a familiarity with the interface and concepts in 3ds Max.


We have been trying to find a GPU base rendering engine for a couple of years, and were pleased to find NVIDIA Iray+ in the state it is in. (Easy to interface to, good material interface and Interactive mode)

SketchUp does no rendering of their own, and leaves the creation of rendering interfaces up to third parties like Render Plus. There are several companies offering rendering solutions for SketchUp.

In general, SketchUp users are looking for a quick, but good rendering of their models which is much better than the OpenGL rendering provided by SketchUp, but not necessarily as good as the best renderings available with Iray and other good rendering products. Many people spend the hours necessary to create a good rendering. But most people would like to get a rendering in 5 or 10 minutes which is good enough for their immediate needs.

Iray+ lets us make good quality rendering quickly, and then make much better renderings by letting IRay+ continue to render additional samples in wither Interactive or Photoreal mode.

Render Plus, based on our current rendering products, has a good reputation for creating a simple user interface which makes it easy (relatively) to render SketchUp models.

What is Iray+?

An introduction to the plug-in Allura integrtates Iray+ into SketchUp. Iray is a physically based ray tracing renderer with accurate materials based on NVIDIA’s Material Definition (MDL) standard. This physically accurate engine allows you to create the highest quality images and animations with a real-world approach to materials, cameras and lighting. The lighting in an Iray+ rendered image is authentic to the real world, as all light interactions in your scene are represented accurately.

Iray+ is based on the NVIDIA technology, Iray, which is used in many professional high-end applications and by top design and visualization companies around the world. Iray+ boasts improvements including an easy to understand material structure and usability enhancements.

Iray+ extends the capabilities of the Iray implementation currently included in Allura, including new features such as full MDL support, interactive rendering, support for cloud or remote renderings and an improved approach to using and creating physically accurate materials.

The Allura plugin includes 2 renderers; Iray+ Photoreal and Iray+ Interactive. The Iray+ Photoreal renderer creates production images while the Iray+ Interactive renderer allows you to navigate models in real-time with results that are sometimes almost indistinguishable from the Photoreal renderer.

Allrra quickly assigns SketchUp materials to Iray Base Materials, which enables you to create the materials you need in minutes.

Our Light Liubrary and and physically accurate sky system mean all lighting is representative of the real world.

Why we Integrated Iray+

We had previously spent about a year integrating a GPU renderer from another developer, but ran into problem after problem. They had a SDK for developers, but hadn’t used the SDK for their own product. As a result almost every time we tried to implement a feature, the discovered that they need to expose it in the SDK so we could use it, and then after exposing it, we discovered bugs in it that they then needed to fix. After a year we abandoned the project.

However a couple months later we learned about Iray+, NVIDIA and Lightworks and decided to give the Iray+ rendering engine a try.

The Iray+ SDK was much easier to work with. We discovered a few problems, but have been able to work around most of them. Many, many features were already exposed in the SDK and worked when we implemented them. Lightworks provided sample code to use most of the features, and our liaison at Lightworks helped us find example code for more complicated needs.

We were able to start rendering SketchUp models in just a week or two, and have been very successful implementing the features we need for our first product. We are concentrating on the features SketchUp users will need first and will add additional features such as a full Material Editor, Animation, and Light Balancing in later versions.

Why use Iray+?

Allura and Iray are based on the fundamental concepts of the real world, with lighting physics, photographic settings and the structure of materials all true to life. We use real-world concepts and present the minimum necessary parameters needed to get stunning images and animations.

Interactive Rendering

The Allura Iray+ Interactive renderer uses advanced approximation algorithms to mimic realism while minimizing unwanted noise. This gives you greater speed in your workflow. The ability to use both renderers simultaneously means you can quickly preview your scene with Iray+ Interactive renderer on your workstation and then switch to the Iray+ Photoreal renderer for your production work.


We have designed Allura to complement your existing workflows, not disrupt them. We have kept the number of Iray+ specific UIs to a minimum and where possible we defer to SketchUp to accomplish most tasks. Where we do use our own objects and parameters we present them clearly and in the familiar formats used by 3ds Max. powerful


Iray+ is designed to make optimal use of GPU hardware to ensure that your rendering is as fast and as powerful as possible. We recommend using NVIDIA GPUs to enhance the performance of your rendering.

The utilization of customers GPUs is a powerful fator for Allura. SketchUp itself is very GPU intensive while editing and viewing your model, so many SketchUp users already have a good GPU. Put your GPU to use for your renderings. You will be pleased to see how it can improve their rendering speeds.

NVIDIA’s Iray is already used by professionals in many industries including automotive, jewelry, architecture, product, interior design and many more. Now you can use this power for your SketchUp Renderings.

Download and Installation

Download Allura

Download a the latest version of Allura from this page: Allura Downloads

After downloading the .ZIP file, click on the file name inside to install Allura.

Start SketchUp

Download SketchUp if you don't have it yet. (Allura works with both the free, make version of SketchUp and the professional version of SketchUp.)

Start Allura

Select Allura Load from the SketchUp Extensions menu.

Test Results

One of our best and oldest clients, who tried Allura GPU said:

It is very fast in interactive which would probably be fine for me, not really tried Photoreal, but it works... and I can tell already you get a lot better images and lot quicker and there seems less of the jagged edges you got with high contrast edges....compared to other products even on my laptop.
The navigation is mind blowing and I am able to obit etc. and pick and choose view angles in real time even with my older video card.
Glass looks really good.
Overall very, very impressed.

Concepts and Features


Rendering Process

A Canon 5D Mk II SLR rendered in Iray+

The preceding sections described the input, process, and output that map to the phases of the rendering process:

  • Input — The scene, which contains the description of the world and a position and direction from which it is viewed. The more comprehensive and detailed the description, the more realistically light interaction with surfaces and volumes can be modelled.
You will create your scene in SketchUp.
  • Rendering Process — The renderer, which processes the scene description. The algorithms the renderer implements determine its abilities to record and render the behavior of light and its interaction with objects.
  • Output — The output of the rendering process, which is an image — the record of what the camera "saw". The quality of the image is determined by the sophistication of the file storage format and the capabilities of the output device used to display the image.

Material Concepts

In Allura you are presented with a wide variety of base materials, which form starting points that can be adapted to represent almost any material with accuracy.

You assign a base material - such as metal, plastic, ceramic, etc. to your SketchUp materials, and the base material is used to define the rendering characteristics.

Still Life with Rendered Materials

Lighting Concepts

Allura has no slow down from adding additional light sources

Lighting in an Allura scene can come from three sources: global illumination from the environment, emissive materials or artificial lights within the scene. A scene can be lit entirely by one of these sources, or by a combination of the three. These three broad categories can be further subdivided into more specific light sources or light types. The environment lighting can come either directly from an IBL (image-based lighting), or from a procedural sun & sky simulation environment called PhysicalSky. The artificial lights come in various types, some of which are controlled by Allura light types.

The lighting systems in Iray+ and Allura are all physically correct; if you put data from the real world in to a model or simulation you will get accurate lighting out. This is perfect for studying light in simulation, and for creating realistic animation. The PhysicalSky environment is ideal for daylight studies and will give accurate luminance levels in any model.

Interior scene lit with Iray+ Lighting

Environment lighting

Allura uses the concept of environments to describe the world around the scene. These serve to provide the visible background to the image (in the absence of a backplate) and also to light the scene. The IBL environment can be specified as either a sphere or hemisphere, and additional parameters that allow you to control the dome size and various ground plane effects.

Allura also provides a powerful procedural environment called PhysicalSky. This generates a physically realistic, high dynamic range sky dome around a scene. You can control many aspects of this dome including the overall intensity, as well as the sun's position and appearance in the sky (the sun position can be set either directly with an altitude-azimuth coordinate system, or by using the comprehensive date/time/location panel). As this is physically accurate, you will see realistic halo effects around the sun disk, haze in the atmosphere, sky color etc. artificial lighting

Allura has several types of artificial light which can be used to partially or fully illuminate a scene. These light types integrate seamlessly into your existing workflow.

Feature List


Utilizes all supported GPUs and CPUs within the machine, with user control of resources

Physically based path-trace rendering in its own Window provides accurate preview of final results while adjusting scenes

Super-fast Iray+ Interactive ray tracing provides immediate feedback on view and lighting edits

Optimized sampling for accurate caustics and highly indirect lighting

Supports SketchUp Section Plane slices through entire max scene for interior visualization


Physically based materials which use Base Materials and layering

SketchUp Textures are automatically mapped to materials.


No slow down from adding additional light sources

Interactive updates while adjusting tone and lighting parameter.

Image based lighting for fast photographic environment lighting

Supports standard and IES lights

Real-world units of lighting attributes for accurate simulation

Lighting from emissive (self illuminated) materials & geometry (Photoreal mode only)

Physical Sun and Sky System for lighting simulation based on date, time, and location

Continual feedback with progressive rendering of final results after scene adjustments

Effortless switching between fast ray tracing (Iray+ Interactive) and accurate path tracing (Iray+ Photoreal)

Interactive tone mapping for quickly achieving desired exposure, white balance, and contrast adjustments


See: Allura Tutorials


Using Materials

Allura will automatically create materials from your SketchUp materials, utilizing SketchUp settings for Transparency, Texture and color.

Using a right click and Allura/Edit Material you can add Rendering Parameters such as Reflection, Index of Refraction and special base material types.

[[File:Iray materials.png|frame|left|Right click anf load the Allura Material Wizard

See: Allura Material Wizard

Material Libraries

Iray+ Materials

Material Components

Noise Maps


Physical Sky

PhysicalSky generates a physically realistic, high dynamic range sky dome around a scene so you can create stills and animations for any time of the day at any location in the world.

An alternative is to use an HDRI Image for lighting and the sky.

HDRi - Image Based Lighting

An HDRi Image (Image Based Lighting) gives you the use of HDRI type environments for scene lighting. This can also be used as a background for your scene, or purely for lighting purposes.

An alternative is to use the built-in high dynamic range sun and sky system: Physical Sky.

To achieve realistic lighting results it is important to ensure that the chosen HDRI or IBL has a realistic dynamic range. For example, HDRIs of exteriors often do not show the sun as being sufficiently bright compared to the rest of the image. The sun (unobscured by cloud) should be of the order of 100,000 times brighter than the surrounding sky. If the sun is significantly fainter than this, the final image may be unrealistic. Typical results are an overly blue tint to the scene (due to the relatively stronger contribution from the sky), soft shadows, and a general lack of contrast.

Allura Lights

You can place artificial lights, (light bulbs or fixtures), into SketchUp using the Allura Light Wizard on the AlluraToolbar

Allura Emission

Iray+ Emission, (Glow), allows any geometry to have emissive properties, which lets you create objects such as screens, LEDs, light bulbs and projections. Emissive materials can use textured emission through bitmaps or use standard light profiles.

Glow or Emission can be set using the Glow tab of the Allura Material Wizard'' .

  • Note: The Allura Interactive Renderer will not display illumination of the scene; the object itself will be shown illuminated, but will not emit light.


The Camera is automatically defined by the Camera and FOV settings in SketchUp.

Tone Mapping

The tone mapper allows various controls over the look of your scene. These can be used during rendering without interrupting progress. These can be found in the Tone tab of the Allura interface.

Tone Ribbon.png


Render Setup

Allura has two renderers, Photoreal and Interactive.

The Phororeal renderer delivers the best results, and is a good choice as your production renderer.

Interactive mode allows easier movement with your scene, and images resolve faster.

See: Allura Rendering Modes


Section Planes

Allura will locate and you your SketchUp Section Plane.

Object outside the section plane will be invisible, but will still block light and cast shadows.

This lets you, for example, section out a wall and window, but still see the light and shadows as effected by the window.


Compatibility with other SketchUp Renderers

Some rendering settings you may have make with IRender nXt or ArielVision will carry over to Allura. But there may be differences in their interpretation.

System Requirements

Minimum Requirements

  • Windows® 7 64-bit Professional operating system;
  • 64-bit Intel or AMD multi core processor;
  • 4GB Ram;
  • 2GB free disk space for installation;
  • NVIDIA GPU with the following minimum specifications:
  • CUDA compute capability 2.0 or higher;
  • Driver needs to support CUDA 8.0 or higher. For Windows, this depends upon having NVIDIA Quadro driver version 367 or later;
  • Note: Iray+ Interactive requires these specifications.

NOTE: CPU-only mode

Iray+ will run without a compatible GPU, but for best performance we recommend using GPUs. If your GPU does not meet the minimum requirements then Iray+ will automatically use CPU rendering.

Recommended Requirements

  • Windows® 8 or Windows® 7 64-bit Professional operating system;
  • 64-bit Intel or AMD multi core processor;
  • 8GB Ram;
  • 2GB free disk space for installation;
  • 2x NVIDIA GPUs (one dedicated to Iray+) with the following minimum specifications:
  • CUDA compute capability 2.0 or higher;
Driver needs to support CUDA 8.0 or higher. For Windows, it is recommended to use NVIDIA Quadro driver version 372 or later;

Interactive Mode

Note: Iray+ Interactive requires these specifications.

  • Iray+ Interactive (IRT) Requirements
  • GPUs with CUDA Compute Capability 2.0 or above are supported by Iray+ Interactive, i.e. of the Fermi, Kepler, Maxwell and Pascal generations. The following device configurations are supported:
  • Arbitrary combinations of Compute Capability 2.x devices;
  • Compute Capability 3.0 devices only;
  • Compute Capability 3.5 devices only.

Note: The following device configurations are not supported:

  • Mixing devices between generations;
  • Combining Compute Capability 3.0 and Compute Capability 3.5 devices;
  • Switching between different GPU generations at runtime, for example, switching from a Compute Capability 3.0 to a Compute Capability 2.0 device.

Driver requirements

  • The driver needs to support CUDA 8.0.


A list of compatible GPUs can be found here.