The Lightflow Rendering Tools
FAQ


Q: How to produce fast previews with low quality ?

A: There are many ways, that may also be combined.
The first is to turn off antialiasing, that is to say to set "aa-threshold" to 3.0 (with pinhole cameras). This is probably the method that provides the fastest results.
The second is to use ray-tracing caches, by setting the "caching" parameter in the "default" interface. This method produces fuzzy reflections and refractions but works correctly with everything else.
The third is to turn off some features such as volumetric rendering, shadows or displacement mapping. This can be achieved by setting the corresponding attributes in the "default" interface.


Q: How to enhance rendering times ?

A:The first technique is to lower antialiasing. This may be achieved both by decreasing the "aa-samples" values, for example using 2 and 3 instead of 2 and 4, and by increasing the "aa-threshold".
Another important factor is the amount of memory used for caching textures, surfaces, volumes, etc.
Sometimes, if data is much larger than the corresponding cache, the rendering could be slower than what it might be. So you should always set the caches to be the largest possible.
For example, if you want to dedicate 200Mb of RAM to the renderer, good values for texture, surface-engine and volumetric-engine caches may be 30Mb, 110Mb and 60Mb respectively (but you may configure it differently for a particular scene if you know in advance what is its structure).


Q: How to view renderings in progress ?

A:Simply load the output image during rendering, with your preferred image viewer. The images are usually updated and rewritten to disk every few seconds.


Q: After I have activated the production of caustics, my image looks grainy. What do I have to do ?

A:Probably this is due to a low value for the second parameter in the "photon-clustering-count" attribute of the "default" interface. Try incrementing it, for example using a value of about 300.