Physics/Science of Light (PART 15)

(How you could implement it + create dramatic compelling art scenes)

Render Styles

(A way of describing light and surface)

Compressed Range

Lighting effects attempt to approximate reality, but exposure effects are minimized by compressing the value range.

This type of render style is achieved by intensifying the shadows and decreasing the strength of the highlights more than what you would see in reality. This allows you to fit all the values in a balanced dynamic range. Rules aren't broken in terms of value relativity; however the range is considerably more compressed than what would be normally seen with the eyes or camera. This rendering style is similar to how HDR photography is produced.

Key Weighted

Separates lit areas from shadowed areas on the value spectrum to approximate strong exposure effects.

In this rendering style your compressing the shadow areas and compressing the light areas and separating them dramatically from each other to give you a strong exposure effect.

Value Distribution

Treats lit areas as high key and shadows areas as low-key. In this render style, you're amplifying the value ranges in extreme; the lit areas are dramatically increased in value and your shadows are considerably low key in value; there is very little middle ground.

Here's a good example, this painting has very bright values complementing the very dark values yet to a certain degree the details in the shadows and highlights are still present. The two opposing value ranges are contrasting dramatically amongst each other and there is not much distinction of anything in between ; little to non middle values are present.The fall-offs on the terminators are transitioning dramatically quick and the strong separation of contrasting values creates strong exposure effects. Saturating the edges that border the terminator and exposed areas are required to really pull of this render style and make it look realistic.

Cel Shading

Flattens out lit and shadow areas completely, turning the terminus into a hard edge.

Your pretty familiar with this type of rendering style if you've watched cartoons, it's pretty cheap to produce a bunch of frames with this style. Essentially what your doing is flattening out both the highlight and the shadow, and turning the terminator/terminus into a hard edge; that's going to be true of both cast shadows and form shadows.

Pros:

-very cheap, easy, quick to produce

Cons:

-a lot of dimension is lost; therefore it can only be suggested now through the shape of the terminus

-colours must be carefully chosen so that the limited amount of colours available are able to describe the forms effectively

Unless you're aiming for the extreme stylistic effect-you want to make sure your highlights and shadow colours are not too far from each other.

Hybrid cel shading

Simplifies lighting by either having a more hard-edged terminus, or by flattening the light in either lit or shadow areas.

In this type of rendering your completely flattening out either the highlight or the shadow, and allow one of the sides to have a little bit more dimension. You're still trying to get the feeling of the cel shaded image.

You'll probably get the same speed, convenience and simplicity of the simple cel shading rendering. This rendering style allows you to have a softer terminus (like 2nd ball) but you're not rendering it much in the highlight and shadow areas. You are flattening things out as you possibly can just to simplify the process. This can work in most cases because we're used to seeing this style in certain lighting situations where the shadows and highlights feel flat because of overexposure.

Hybrid Shading

Combines angled lighting with form-describing frontal lighting, so forms darken as they turn away from the viewer regardless of light source.

Its kind of a cheat, what it is iss its mixing the dramatic effects of light coming from an angle, or from various angles, depending on what your lighting scheme is. So the reason why this one works because its true to our experience because we have a great sense of depth in our world thats coming from the way our brains and our eyes are seeing things that we just dont have in a painting.

Great for character concepts, where interpreting forms in a painting may be important.Anyone who uses watercolour or other things over a pencil drawing thats rendered is going to have a little bit of this effect just because the pencil lines create an edge on both sides,

(this is arthur rack)

Wrapped Light Shading

Light is wrapped beyond the terminus and shadows are softer-edged, regardless of the type of light source.

This one kind of a cheat, it won't be true to our experience, but what it works in doing is creating an emotional effect. It's softer; making the scene more friendly. This one lacks a terminus separating the lights and shadows.

(so heres an example from muka)

(H.B. Lewis)

Under-rendered Shading

Diffuse light clusters around brightest area, ignoring realistic lighting fall-off. Including no terminus. Looks stylized-vaguely shiny.

In this one your concentrating your light source towards a highlight point, and there's no terminus; essentially it fades off abruptly from there. It ends up making everything feel vaguely shiny and it's approximating a soft diffused reflection, again, it's a stylistic statement.You don't want to use this rendering style on a complex image because it will quickly get convoluted.

Simplified Shading

Similar to cel-shading, but with less regard to form. Emphasis is on shape and texture. Light rakes across the shapes to maximize texture.Usually the light for these scenes, they kind of have it coming from the side and always raking across to emphasis those textural attributes.It generally tends to get pretty flat in the highlights. And a bit abstract in the shadow areas.

You may see this often used in the backgrounds, (this is from sleeping beauty),you'll notice the shadows being cast because of the light raking across the object catching the textures. The light is wrapping around the form more than it would realistically. The point and emphasis here is on the textural properties of the surface.

Minimal

This one is not in any way true to experience, these are totally stylistic decisions, they're not even accepted much culturally, you don't see these in art a whole lot. Unless you're looking back at old Persian art or stefan dulack. In this rendering style your letting everything remain flat-using the simplest way you can to describe the form. Your basically avoiding cast shadows, terminus, highlights and realistic textural details. There may be textural properties but it's primarily surface pattern like. There's no real surface properties here.

Non-Representational

This one you won't see often, it's all about the style-not about describing the forms,