2D cel and cartoon effects can easily be achieved with the V-Ray Toon Material. Use this material to make your scene get that hand-drawn look. Controlling the shadows and lights received by the material in combination with material transparency, gotten from Object or Material IDs, allows for fine-tuning the result. You can take advantage of the other standard V-Ray material options such as reflection, refraction, anisotropy, subsurface scattering, and bump/normal mapping to set up the render to your liking.

Base Color – Base texture blended with the color from the diffuse (Cell Shading) ramp. See the Diffuse Color with Cell Shading Ramp example below.

Roughness – Used to simulate rough surfaces or surfaces covered with dust (for example, skin, or the surface of the Moon).

The Cell Shading ramp controls the diffuse color based on the amount of light received. Position 0.0 maps to light intensity 0.0, position 1.0 maps to light intensity 1.0 and above. See the Cell Shading Ramp example below.

Bump Type – Determines how the Bump Map parameter is interpreted.

Amount – A multiplier for the bump map effect.

Opacity Mode – Controls how the opacity map works.

Normal – The opacity map is evaluated as normal: the surface lighting is computed and the ray is continued for the transparent effect. The opacity texture is filtered as normal.
Clip – The surface is shaded as either fully opaque or fully transparent depending on the value of the opacity map (i.e. without any randomness). This mode also disables the filtering of the opacity texture. This is the fastest mode, but it might increase flickering when rendering animations. 
Stochastic – The surface is randomly shaded as either fully opaque or fully transparent so that on average it appears to be with the correct transparency. This mode reduces lighting calculations but might introduce some noise in areas where the opacity map has gray-scale values. The opacity texture is still filtered as normal.

Opacity – Assigns opacity to the material where 1.0 is completely opaque and 0.0 is completely transparent.

Color – The self-illumination color of the material.

Multiplier – A multiplier for the self-illumination of the material.

Contribute to Global Illumination – When enabled, the self-illumination color affects GI computations.

The Shadows parameters control the shadow received by the material and not the shadow cast from the material.

Shadow Blend On – When disabled, the shadow is considered as negative light amount and used by the cell shading ramp for color selection. When enabled, the shadow is rendered separately and can be blended with the diffuse color.

Color – Texture that modifies the shadow color.

Opacity – Strength of the shadow when blending with the diffuse color. A value of 0 means completely transparent shadow (or no shadow), while a value of 1 gives full shadow result.

Replace Light Control – When enabled, the color for all lights illuminating an object with the current material is replaced by light Color.

Control – Replacement color for the original light color.

Blend Mode – Mode for blending the original light with the diffuse color.

None
Normal
Over
Add
Subtract
Multiply
Lighten
Darken
Saturate
Desaturate
Illuminate

Blend Intensity – Amount for blending the original light and the diffuse color. A value of 0 results in no light blending, while a value of 1 results in full light blending. A texture map can be used here.

Color – The reflection color dims the diffuse surface color.

Glossiness – Controls the sharpness of reflections. A value of 1.0 means perfect mirror-like reflection; lower values produce blurry or glossy reflections. Use the Subdivs parameter below to control the quality of glossy reflections.

Use Fresnel – When enabled, makes the reflection strength dependent on the viewing angle of the surface. Some materials in nature (glass, etc.) reflect light in this manner. Note that the Fresnel effect depends on the index of refraction (IOR) as well.

Lock Fresnel IOR to Refraction IOR – Unlocks the Fresnel IOR parameter for finer control over the reflections. When this is enabled, the Fresnel IOR is locked to the Refraction IOR.

Fresnel IOR – The IOR to use when calculating Fresnel reflections. Normally this is locked to the Refraction IOR parameter, but you can unlock it for finer control.

Specular Highlight Color – Controls the specular color based on the amount of light received. Position 0.0 maps to light intensity 0.0, position 1.0 maps to light intensity 1.0 and above.

Specular Highlight – Offers two modes to set the anisotropy highlight:

From Ramp – Using a curve and points to set the highlights.
From Texture – Textured highlight allows a greater degree of control over the final look. It uses the same V-Ray Material highlight anisotropy UV space to map a texture over the highlight.

Highlight Shape – A curve controlling the shape of the highlight.

Split U/Split V – Amount for highlight splitting in the U/V tangent direction.

Highlight Rotation – Amount for highlight rotation. A value of 0 means no highlight rotation and a value of 1 results in 360 degree rotation.

Advanced

Trace Reflections – Enables reflections for the material.

Max Depth – The number of times a ray can be reflected. Scenes with lots of reflective and refractive surfaces may require higher values to look correct.

Enable Dim Distance – Enables the Dim Distance parameter which allows you to stop tracing reflection rays after a certain distance.

Dim Distance – Specifies a distance after which the reflection rays are not traced.

Dim Fall-off – A fall off radius for the dim distance.

Affect Channels – Specifies which channels are going to be affected by the reflectivity of the material.

Color Only – The reflectivity affects only the RGB channel of the final render.
Color+alpha – Causes the material to transmit the alpha of the reflected objects, instead of displaying an opaque alpha.
All channels – All channels and render elements are affected by the reflectivity of the material.

Color – Refraction color. Note that the actual refraction color depends on the reflection color as well.

Glossiness – Controls the sharpness of refractions. A value of 1.0 means perfect glass-like refraction; lower values produce blurry or glossy refractions.

Index of Refraction – Index of refraction for the material, which describes the way light bends when crossing the material surface. A value of 1.0 means the light does not change direction.

Affect Shadows – Causes the material to cast transparent shadows to create a simple caustic effect dependent on the Refraction Color and the Fog Color. For accurate caustic calculations, disable this parameter and instead enable Caustics in the V-Ray Renderer. Simultaneous usage of both Caustics and Affects Shadows can be used for artistic purposes but does not produce a physically correct result.

Enable – Enables the calculation of true light wavelength dispersion.

Abbe – Increases or decreases the dispersion effect. Lowering it widens the dispersion and vice versa.

Color – The attenuation of light as it passes through the material. This option helps simulate the fact that thick objects look less transparent than thin objects. Note that the effect of the fog color depends on the absolute size of the objects and is therefore scene-dependent. 

Multiplier – The strength of the fog effect. Smaller values reduce the effect of the fog, making the material more transparent. Larger values increase the fog effect, making the material more opaque.

Bias – Changes the way the fog color is applied. Negative values make the thin parts of the objects more transparent and the thicker parts more opaque and vice-versa (positive numbers make thinner parts more opaque and thicker parts more transparent).

Enable – Enables sub-surface scattering for the material.

Color – Normally the color of the sub-surface scattering effect depends on the Fog color; this parameter allows you to additionally tint the SSS effect.

Fwd/Bwd Coeff – Controls the direction of scattering for a ray. A value of 0.0 means a ray can only go forward (away from the surface, inside the object); 0.5 means that a ray has an equal chance of going forward or backward; 1.0 means a ray is scattered backward (towards the surface, to the outside of the object).

Scatter Bounces – Controls how many times the rays bounce inside the object.

Scatter Coeff – The amount of scattering inside the object. 0.0 means rays are scattered in all directions; 1.0 means a ray cannot change its direction inside the sub-surface volume.

Thickness – Limits the rays that are traced below the surface. This is useful if you do not want or don't need to trace the whole sub-surface volume.

Environment Fog – When enabled, V-Ray traces direct lighting into the material.

Trace Refractions – Enables refractions for the current material.

Max Depth – The number of times a ray can be refracted. Scenes with lots of refractive and reflective surfaces may require higher values to look correct.

Affect Channels – Specifies which channels are going to be affected by the transparency of the material

Color Only – The transparency affects only the RGB channel of the final render.
Color+Alpha – This causes the material to transmit the alpha of the refracted objects, instead of displaying an opaque alpha. 
All Channels – All channels and render elements are affected by the transparency of the material.

Transparency ID From – Source for IDs used by the material transparency list. Currently supported sources are Object ID and Material ID.

ID count – Specifies the number of ID sources.

Cutoff Threshold – A threshold below which reflections/refractions are not traced. V-Ray tries to estimate the contribution of reflections/refractions to the image, and if it is below this threshold, these effects are not computed. Do not set this to 0.0 as it may cause excessively long render times in some cases.

Double-sided – When enabled, V-Ray flips the normals for back-facing surfaces with this material assigned. Otherwise, the lighting on the "outer" side of the material is computed always. Can be used to achieve a fake translucent effect for thin objects like paper.

Reflect On Back Side – When disabled, V-Ray calculates reflections for the front side of objects only. Checking it makes V-Ray calculate the reflections for the back sides of objects too.

Use Irradiance map – When enabled, the irradiance map is used to approximate diffuse indirect illumination for the material. If disabled, Brute Force GI is used in which case the quality of the Brute Force GI is determined by the Subdivs parameter of the Irradiance Map. This can be used for objects in the scene which have small details that are not approximated very well by the irradiance map.

Fix Dark Edges – When enabled, fixes the dark edges that sometimes appear on objects with glossy materials.