Biased or UnBiased Rendering Engine? Why Choose When You Can Have Both!

If you're unsure which type of rendering engine is right for your business, IRender nXt users have both! Our rendering extension for SketchUp includes a biased rendering engine and an unbiased rendering engine. Either can be selected at any time to render your SketchUp models. With a little experimentation you'll find that it's easy to select the engine that meets the requirements for each project.

• Use biased when you want a high-quality rendering quickly.
• Use unbiased for even better renderings which take a little longer.

Look for the IRender nXt toolbar and open the Rendering Options dialog

Click the "Render" tab to display the available rendering engines. IRender nXt provides biased and unbiased methods for creating photo-realistic renderings from SketchUp models.

What is your priority?

• I need to finish my rendering as quickly as possible

A biased rendering engine will produce a high quality image from fewer passes than an unbiased engine. You'll have a rendering that is ready to share sooner when you select the biased engine.

• I need to make the best rendering possible

An unbiased rendering engine will produce a more accurate solution. When you require an image with mathematically perfect lighting and time isn't as important, select the unbiased engine.

• I need to make an animation

Biased rendering engines are the standard for computer generated animations, and although either IRender nXt engine can be used, you'll probably complete the video faster using the biased engine.

What's the difference?

In the simplest language, biased engines are built for speed, unbiased engines are built for accuracy.

When Speed is the Priority - Select the IRender nXt Biased Rendering Method

Statistics:
Rendering Method: Biased
Image Size (pixels): 2000 x 1000
Iterations (Rendering Passes): 10
Processing Time: 9 minutes, 10 seconds

Notes:
The IRender nXt biased rendering engine requires fewer iterations to produce a solution. When time is the priority, the biased engine will deliver a solution for your presentation rendering faster.

Statistics:
Rendering Method: Biased
Image Size (pixels): 2000 x 1000
Iterations (Rendering Passes): 150
Processing Time: 2 hours 15 minutes, 18.7 seconds

Notes:
The IRender nXt biased rendering engine, like the unbiased engine will continue to solve lighting, and improve the quality of the rendering with each successive pass. The benefit of biased rendering is that a solution is achieved with fewer passes and therefore biased is the faster of the two methods.

When Accuracy is the Priority - Select the IRender nXt Unbiased Engine

Statistics:
Image Size (pixels): 2000 x 1000 pixels
Rendering Passes: 20
Processing Time: 1 minutes, 14 seconds

Notes:
During early passes the unbiased rendering engine produces noisy images that appear grainy, not unlike underexposed photographs. As more passes are completed, the unbiased engine will eventually eliminate the noise resulting in a mathematically correct solution.

Statistics:
Image Size (pixels): 2000 x 1000 pixels
Rendering Passes: 1000
Processing Time: 2 hours 20 minutes, 36 seconds

Notes:
This rendering was stopped after 1000 passes. If allowed to continue, the unbiased engine can improve on the solution indefinitely.

Rendering Lingo - Biased and Unbiased

Biased rendering methods emphasize efficiency over accuracy. A sample bias is introduced early to achieve a solution quickly.

Although the accuracy of the image will not match unbiased methods, presentation quality renderings can be produced with fewer rendering passes and so are typically available sooner. With IRender nXt the artist can intervene at any time (even while the rendering is processing) and can produce an image that is thoroughly accurate.

Unbiased rendering methods emphasize accuracy over efficiency. Each light path for each pixel in the image is calculated as accurately as possible.

Image quality is improved incrementally during each pass and although early passes will produce noisy images, the unbiased method will eventually deliver a correct solution. Technically speaking, unbiased renderings are never fully solved and if allowed will continue to improve the solution indefinitely.