Difference between path tracer and packet mode

What is the difference between Packet mode and path tracer .

When to use packet mode and when to use path tracer Engine.

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Permalink Reply by Render Plus on May 23, 2011 at 6:43am

The Path Tracer is a new, alternate rendering engine for IRender nXt.

You can render with either nXt Packet Mode or nXt Path Tracer mode.

Packet Mode vs Path Tracer

nXt Packet Mode processes packets of rays, while nXt Path Tracer processes individual light paths.

The Path Tracer can provide a better quality finished product for many models (with a simpler setup), but does so at the expense of a more complex and time-consuming calculation. The Path Tracer begins by displaying a very grainy or “noisy” image which gradually refines and becomes smooth. This process is known as convergence. Some scenes will converge very quickly, others will take many hours.

Additional Notes

In general, images rendered using the Path Tracer will take longer to converge than images rendered using the Standard method. Interior daylight simulations, particularly those scenes where the windows are relatively small, may take much longer. On the other hand, the Path Tracer is less sensitive to instancing, plants, and displacement maps. Models which rely heavily on these features may actually converge faster using the Path Tracer.
The standard Packet Tracer algorithm produces a very high-quality simulation. For many models, the difference in quality between the Packet Tracer method and the Path Tracer can be very subtle, particularly if indirect lighting is enabled. The difference in quality may not be worth the extra processing time.
The Path Tracer is almost always easier to configure and set up than the Packet Tracer method. Advanced settings such as reflection shaders, daylight portals, and ambient lighting, are not used when the Path Tracer engine is selected.
Certain advanced effects, such as caustics or blurry transmission, can be calculated with better accuracy using the Path Tracer.