Quote - Sub- Surface Scattering. Certain materials (skin, orange juice, wax) do not reflect all light on their surface. Light enters the object and is reflected inside the object. IMHO it is possible to fake SSS without Ray Tracing.
Well, it can be done without ray tracing, it's only an illumination model.

SSS is no illumination modell, it's more a volumetric shading system. SSS works with all light sources. Light enters the object and is reflected in various depths. That is a material property.

Quote - The difference between ray tracing and not is that in the second the rays of propagates in straight light and ends when hit the last not transparent object.
With ray tracing the rays can be reflected and then in another direction where can be reflected again and also the rays can bend due refraction.
But the method without ray tracing can be very fast and done in real time.
I don't know which renderers beside games that use this method.
Poser 4 I don't know what it is, it looks as some limited ray tracer because the scene appears slowly line by line and not in an instant with all whole scene rendered.

Poser 4 is a scanline renderer. FireFly is a scanline based renderer which uses ray tracing when needed.

Graphic adapters are capable of rendering certain scenes in real time. They use the scanline algorythm. Up-to-date graphic processors are comparable to your main processor in complexity, to make real time graphics possible. They are limited in the number of polygons they can handle, and the texture size. Since scanline needs a collision test for every polygon in every pixel, it looses its performance when the scene gets to large.

Graphic adapters render in real time, software renderers usually do not. Real time is good for games, the best graphic adapters can do a lot. But high-res textures, ambient occlusion, real reflection and refractions can only be faked. Obviously faked.

If you don't plan to do photorealistic work this can be enough. If you go for photorealism there need to be ray tracing. And no, it is not "slow", at least not if you have complex scenery. Compare it with cars: true, a Ferrari or Porsche is faster than a truck. But if you need to move a lot of stuff, it will not help.

DAZ Studio and Poser 7 IMHO both have a preview function which is done by your graphics adapter. This preview is probably the best you can get in real time. This is scanline, with all options your graphics adapter can show. Since I haven't spent that much money for mine, I do not use that. See what you can get, see if it is enough.

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