When attempting to create 3D renders that mimic the artistic style that is so typical in Japanese anime, there are many choices to make.  The primary choice is whether to go the photorealistic path or the cel-shaded path, but this not as simple of a choice as it sounds.  There are many options available for cel-shading as well as how you can combine cel-shading and photorealism.  I have created some comparison renders in Carrara 8 using Toon! Pro, a popular cel-shading plugin.  These renders demonstrate four different ways to render the same scene, each having its own appeal and being a viable option:

 

Photorealistic

AnimeDoll in Grass 3D Photorealistic

This first image is a fully photorealistic 3D render.  It is interesting that, even though this model is primarily designed for cel-shaded rendering, it still looks good rendered photorealistically.  If you start paying attention to her hair, which is just a solid object, then you may think it is kind of strange to see on a character in a 3D world, but it still works.  There is precedent for rendering solid hair photorealistically in CG television and movies, not to mention the fact that stop motion puppets often have solid hair.

Fully Cel-shaded with Outline

AnimeDoll in Grass Cel-shaded

In this render, everything is cell shaded and AnimeDoll has an outline.  This is the most similar to traditional anime.  I have never been able to get it to look exactly that same as a 2D drawing, but I think its pretty close.

The outline has been carefully optimized by shading domain.  Toon! Pro allows you to set the outline parameters for the entire scene in one place, but then override them by shading domain.  For instance, the hair has a much thinner outline than her dress or body.  This is because the hair has a lot of detail, and the outline was adding too much black.  Reducing the thickness allows us to benefit from the added detail that the outline brings, but without loosing too much of our color.

Cel-shaded without Outline

AnimeDoll in Grass Cel-shaded No Outline

This render is the same as the last one, but without the outline.  The outline is not always necessary for cel-shading.  The right lighting can bring out the detail in your models with shadows instead of outlines.  Sometimes the generated outlines don’t look quite right or make the render a little messy, so if you can accomplish a sharp result without the outline, you can avoid those problems.  It definitely produces a different look, but that is not necessarily a bad thing.  This scene may not be the best example, however, since I did not adjust my lighting to attempt to optimize my detail shadows.

Cel-shaded with Photorealistic Background

AnimeDoll in Grass Character Cel-shaded

In anime, the background is always a different art style from the foreground.  It is either more detailed, or it is totally abstract, so you should not get hung up on trying to make your background render in exactly the same way as your foreground.  Usually photorealistic elements produce such a stark contrast against cel-shaded elements or 2D animation that it looks out of place, and that is normally not appealing.  Sometimes, it can work, however.  Since backgrounds are often more detailed than the foreground elements in anime, a photorealistic background is not so different in concept.  The photorealism in the background is not nearly as distracting and disturbing as a photorealistic character, like a robot, would be amongst cel-shaded elements.

In this scene, the grass is photorealistic, and I think it looks good.  In fact, I feel it lends it a unique artistic element, not to mention that the grass looks pretty sweet in my humble opinion.