We can see objects because of the reflection of light, and Photoshop's contours simulate all of this. The reflected light of objects with uneven surfaces allows us to feel the unevenness of the surface of the object, because the intensity of light reflected from each part is different, or the degree of whiteness is different, which makes the eyes feel brighter. (White is the bright part, black is the dark part) And if the object is black, it absorbs all the light and does not reflect any light to the human eye. In this way, the person cannot see the object, or cannot feel the object. The bump is just a black plane. White is the opposite.
Contour lines determine the unique material of an object. Where the object should be concave and where it should be convex are controlled by the contour lines. (Contours bring different brightness, and brightness determines the concavity and convexity of an object. Remember, the contours only control the brightness and not the material of the object itself) and a small part of it is related to the numerical parameters. .
The advantage of Photoshop layer styles is that they can be applied at any time. If you want to really use layer styles well, it is very important to be familiar with layer blending modes and correctly understand the contour principle.
A simple refutation of the section line theory of contours
1. We first use bevel relief style to make a three-dimensional button. The parameters are as follows:
2. We add a bevel relief subset contour effect to it.
To achieve this step, let us first understand that contour lines are section lines.
However, we reverse the settings of highlights and shadows, leaving the subset contours unchanged. The specific settings are as shown in the figure below:
What did you see?
Due to changes in external conditions, the three-dimensional feeling presented by the button is exactly opposite to the shape of the subset contour!
Therefore, it is not accurate enough to simply understand contour lines as section lines. It has considerable limitations. If we want to better control contour lines, we must understand its essence.
Understand the nature of contours
Below I use a few examples to try to establish my point of view. If you have any different opinions, please put them forward, thank you!
Use the bevel and embossing in the layer style to get a rough idea. To make the example more intuitive, we set both the highlight mode and the shadow mode to normal, and increase the transparency to 100%. The settings are as shown below. Draw a 100*100PX red square and apply a layer style on this layer.
Output 50
Highlights and shadows are balanced, and the material of the object is not affected in any way.
Output 100
High-gloss white covers the object itself, making the object "disappear" on the white canvas.
Enter 100
Dark-tone black covers the object itself, making it difficult to see the concavity and convexity of the object.
Linear
The brightness is distributed at 90 degrees, with highlights at the top and dark tones at the bottom.
Tapering
The top of the object is covered with white highlight
Taper row - invert the top of the object to be covered with a black shadow
The above text seems obscure and difficult to understand, but after continuous experiments through question and answer sessions with bluelink, let us now reveal the secret.
I only used bevel and embossing when making illustrations, and the "gloss" was the most basic condition, because the effect of bevel and embossing is the most obvious. Although inner shadow and shadow only have one color condition, they can also be explained.
Use inner glow as an example.
The active surface is 20 pixels and the color is black. Although there is only one color condition, it can be explained clearly.
The inner glow is distributed on the edge, and the linear contour determines the color distribution from high to low, so it produces a glow-like effect.
Circular contours also determine color distribution, and black distribution is also distributed according to circular contours.
bluelink: The contour lines of shadow and glow cannot be explained by hatching. . . . . . . .
It seems similar to curves, but the problem is a bit complicated. According to your experience, are the contours of shadow and glow the same as the gloss contours of bevel relief?
kamachen:: Leave aside the curve for now. Let’s talk about the contours of shadow and glow. Because there is only one contour condition for shadow and glow, which is the color next to the blending mode. We all experimented with the normal mode, a basic shadow mode with black under the object. Adjust the contour in the opposite direction, the black shadow becomes white, and the light and dark conditions are again affected by additional conditions.
It can also be combined with the contour option below Bevel Relief.
A default beveled relief contour gives the object a three-dimensional feel. Coupled with the contour conditions below the bevel relief, the default directions are the same, that is, the distribution of light and dark is the same. Adjust it in the opposite direction, and the light and dark distribution is also reversed.
At the same time, what I want to say is that gloss, outer glow, inner shadow, bevel and relief have different effects on objects. For example, the shadow only acts on the outer circle of the object, the inner shadow is on the inner circle, and the gloss is on most areas of the object's surface.
bluelink: If gloss contours are equivalent to contour lines (which according to you it should be, and the former covers the latter), then what is the purpose of setting contour lines?
kamachen: The advanced thing about layer style is that its parameters, angles, contours, blending modes and color-related settings may cause changes in the final effect.
Taking the above picture as an example, the light and dark distribution of different contour lines are opposite. Then adding an angle condition, to put it more purely, we have reversed the contour line again, and the effect is the same.
If you adjust the parameters, blending modes, colors, etc., I don't think I can explain it clearly at such an advanced level. The more conditions are included, the less clear the explanation becomes. All parameters are relevant to the final effect. So you said the role of contour lines, I think it is to match these additional conditions to create a light and dark distribution to achieve the final effect.
But what if there are no contours? Other additional conditions will have no effect. Because they don't know where the most primitive conditions are. It can also be said that the default linear contour creates the most basic relief effect for us.
You can then adjust the angle, height, etc. to influence how the contours work.
bluelink: Well, for contour lines, it is certain to use positioning brightness to reflect the three-dimensional sense of an object. This is also the essence of contour lines, so under the same external conditions, the contours of shadow, glow, and bevel relief The effect achieved by lines is similar. The only difference is that the bevel relief contours have more external conditions and are affected by the gloss contours, so the expression methods are relatively rich, but this does not affect its essence.
As for the section line, it can only be said to be a means to help understanding, because there is only two dimensions in PS. Where does the section line come from? It is just a simulation of light and shadow, which deceives the three-dimensional sense of the human eye.
kamachen: Well, that’s right. Draw a simple diagram
The gloss contours of bevel and relief have two conditions, high light and dark, making it easy to simulate a three-dimensional effect. There is only one condition for in-image luminescence. For example, in the example above, the contour determines the distribution of black within 20 pixels.
In fact, using layer styles is nothing more than creating a three-dimensional effect. While the contour lines are vertical, the image is flat. Not understood as hatching. It's simpler to not imagine it, but to put the contour lines down, or to put our flat canvas up. This also corresponds to the upper contour line.
Now we should all understand that gloss contours, inner shadow contours, inner glow contours, etc. are all the same.
Contour subset
So let's take a look at whether the subset of contour lines under the slope and relief are the same as other contour lines?
First, we add a texture pattern to the bevel and relief. This pattern material is also given a relief effect.
We then change the gloss contour direction to see if this texture is affected by the gloss contour.
It looks like this texture subset is also affected by gloss contours, which is nice.
We add a subset of contours below the bevel and relief. In order to make the effect more obvious, we use a reverse direction to display it.
What did you see? This subset of contours follows its own distribution pattern, but does not affect the function of the gloss contours. It can be seen that the relief effect of the texture pattern has not changed.
The reason why Adobe sets up such a subset in bevel and relief is actually to use subset contours to build a more complex three-dimensional sense to achieve richer details. In other words, this subset is an enhancement of bevel and relief. Is that so? It is more convincing to look at examples.
We adjusted the highlight and shadow colors to green and blue to highlight whether the bevel and embossing had any effect on the subset contours.
What did you see? Highlights change in bevels and reliefs, highlights and shadows change in texture patterns, and subsets of contours also change.
We know this subset cannot be used alone, but the Bevel and Emboss Glossy Contours alone can simulate a three-dimensional effect. Therefore, the subset of contour lines under the bevel and relief are also governed by the gloss contours of the bevel and relief. An additional contour line control is only added to express the texture effect of complex words, but the light and dark changes used also come from the bevel. and relief.
Finally, we can conclude that gloss contours are contour lines. There are only two light and shadow conditions in bevel and relief, which can easily simulate a three-dimensional effect. However, inner shadows only have one condition, which is not enough to simulate complex light and shadow effects.
Finally, it can be concluded that the height of the contour line determines the brightness of the mapped color (that is, the color set in the external conditions). The shape of the contour line corresponds to the distribution position of the mapped color. The distribution of different color brightness ultimately creates a visual three-dimensional sense (illusion). ).
Remember, in the process of understanding contours, do not be influenced by too many external conditions. Use the least conditions, the most basic environment, and the smallest scope of action to experiment. Also, the default linear simulates a most basic style for us, such as a linear relief effect.