In addition to the settings of diameter and hardness, Photoshop also provides very detailed settings for brushes, which makes the brushes rich and colorful, rather than just the simple effects we saw earlier. The shortcut key 〖F5〗 can bring up the brush palette. Note that this brush panel has no dependency on the brush tool. This is the detailed setting palette for the brush. In fact, it should be more appropriately named the Brush Palette.
Click "Brush Tip Shape" on the left side of the Brush palette. If any of the following options (such as Shape Dynamics) are checked, uncheck them all first. Then select the 9 pixel brush in the brush preset list. As shown below. From this we see the familiar diameter and hardness, which serve the same purpose as those we have encountered before, controlling size and edge feathering.
The wavy line at the bottom is a preview of the brush effect, which is equivalent to the effect of drawing a stroke in the image. Whenever we change the settings, this preview will also change.
In fact, the brush we used earlier can be seen as being made up of many dots arranged. If we set the spacing to 100%, we can see the dots arranged end to end, as shown on the left below. If it is set to 200%, you will see that there is a clear gap between the dots, and the gap is just enough to place another dot. As shown below on the right. It can be seen from this that the distance is actually the distance between the centers of each two dots. The larger the distance, the greater the distance between the dots.
That's because the spacing value is a percentage, and the reference for the percentage is the diameter of the brush. When the diameter itself is small, the distance between the dots calculated by this percentage is also small and therefore not noticeable. When the diameter is large, the distance calculated by this percentage is also large, and the effect of the dots becomes obvious.
We can do a comparison experiment, maintain a spacing of 25%, set the diameter to 9 pixels and 90 pixels respectively, and then draw a straight line in the image, and then compare their edges. As shown below on the left. You can see that the edge of the first straight line is smooth, while the edge of the second straight line clearly has arcs. These arcs are composed of the outer edges of many dots, as shown in the right picture below.
Because of this, the spacing should be appropriately reduced when using larger brushes.
But the spacing distance is minimum 1%, and the brush diameter can be up to 2500 pixels. Then when the brush diameter is 2500 pixels, the minimum spacing between the dots reaches 25 pixels, which looks very obvious. If you encounter such a situation, just draw a large rectangle instead.
It should be noted that if the spacing option is turned off, the distance between the dots will be based on the speed of mouse dragging. The dots will be denser in slow places and sparse in fast places.
The brush we used before was a perfect circle. Now with an additional roundness control, we can set the brush shape to an ellipse. Roundness is also a percentage, representing the ratio of the length and diameter of an ellipse. At 100%, it is a perfect circle, and at 0%, the ellipse has the flattest shape. The angle is the tilt angle of the ellipse. When the roundness is 100%, the angle is meaningless, because a perfect circle will look the same no matter how it is tilted.
In addition to entering numerical values to change, you can also drag two control points (red arrows) in the schematic diagram to change the roundness, and click and drag anywhere in the schematic diagram to change the angle.
After using Flip X and Flip Y, although the angle and roundness remain unchanged in the settings, the shape of the brush will change in actual drawing. As shown in the left picture below, the horizontal direction is the effect of flipping X, and the vertical direction is the effect of flipping Y.
It seems that the two flipping effects are the same, both are rotated by a certain angle, but in fact they are not. Flip and rotation are two completely different concepts. As shown in the picture on the right below, if you carefully observe the positions of the three red, green, and blue points on the edge of the ellipse after flipping, you will understand that this is not something that rotation can do. Flip is also called mirroring. Draw the ellipse in the upper left corner of the picture above on paper, then take a mirror and place it at the two thin lines in the picture. The scene you see in the mirror is a mirror image. You can do it yourself and see if the image looks like the picture above.
We talked about the brush spacing issue before, and this spacing is somewhat special under ellipses. We set a brush with a diameter of 20 pixels, an angle of 15, a roundness of 50%, and a spacing of 200%. Hold down the SHIFT key to draw an effect similar to the picture on the left below. I see that the distance between the two straight line brushes is different. Why is this?
Because the ellipse has two standard drawing radii (diameter), one is the longest and the other is the shortest, which are called the long radius (diameter) and the short radius (diameter). The brush spacing is the distance between the centers of the two dots before and after, and this distance is based on the short radius (diameter) as the standard. Note that the spacing we set is 200%. If the long diameter of the ellipse is 10 pixels and the short diameter is 5 pixels, the distance between the centers of the brush dots is 5x200%=10 pixels. At this time, if you draw along the long diameter of the ellipse, you will see that the origins are connected head to tail, because the 10-pixel center distance between the dots is equal to the 10-pixel long diameter of the ellipse itself. Only when drawing along the short diameter direction can you really see the 200% spacing effect. As shown in the middle picture below, the two straight lines in the preview are the long and short diameters of the ellipse, and the left picture is drawn roughly along the direction of these two straight lines.
If the roundness is set larger, such as 60%, then it will be impossible to draw connecting or overlapping dots with a spacing of 200%. As shown below on the right.
If they are to be connected end-to-end along the long radius, then the roundness multiplied by the spacing must equal 1. If it is greater than 1, it will be separated. If it is less than 1, the brush dots will overlap.
Therefore, when the brush is an ellipse, the actual spacing drawn may be smaller than the set spacing size. When the brush is a perfect circle, since the length and diameter are equal, this situation will not occur. To ensure that the brush spacing is equal in any direction, it must be a perfect circle brush.
In addition to perfect circles and ellipses, we will also learn to use arbitrary shapes as brushes in the future.
Now let's take a look at the shape dynamics in the brush settings. First set the spacing to 150% in the nib shape settings. Then click the "Shape Dynamics" option, set the size jitter to 100%, control selection off (you can also select pen pressure if you don't have a drawing tablet device), and select 0% for minimum diameter, angle and roundness. As shown below on the left. You will see the effect as shown in the middle picture below. The so-called jitter means randomness, and the so-called randomness means irregularity. For example, if it is a random single digit, then this number may be 1, 8, or 3, which is completely irregular. Just like when you drop the sand in your hand on the ground, the landing point of the sand grains is random, and the random numbers are unpredictable.
Then the size jitter means the size is random, which means that the diameter of the brush changes irregularly. Therefore, we see that some dots are large and some are small, and there is no change pattern. If you use this brush to draw multiple times, the effect will not be exactly the same each time.
Here we set the spacing to 150% in order to better see the effect of the change in brush dot size. If the spacing is set to the standard 25%, then the effect will be as shown on the right below. Looks a bit like a frayed seal edge.
The larger the value of size jitter (random), the more obvious the effect of jitter (random) is. The greater the size contrast between the brush dots. This percentage is the ratio of the numerical difference between the brush diameter and 1 pixel.
The minimum diameter calculation formula for large and small jitter is: brush diameter - (brush diameter × jitter percentage). If the answer is 0, add 1, and if it is a decimal, round it up.
If the diameter of the brush is 10 pixels and the size jitter is 100%, the range of change is 10 to 1 pixel. If the size jitter is 50%, the range of change is 10~5 pixels.
If the diameter of the brush is 12 pixels, the range of size jitter at 100% is 12 to 1 pixel, and at 50% it is 12 to 6 pixels. 30% of the time it is 12~8 pixels.
The above calculation process is relatively boring, and it may be difficult for everyone to think clearly in a short time. It doesn't matter. Here we just demonstrate a derivation process and control principle. In actual use, such precise calculations are rarely needed. As long as you feel comfortable with it, it's OK.
Note that there is also a minimum diameter option under the size jitter, which is used to control the smallest dot diameter in the size jitter. If the size jitter is 100% and the minimum diameter is 30%, the drawing effect is equivalent to a simple size jitter of 70%. If both are 100%, it is equivalent to no size jitter. However, we have just learned how to calculate the minimum diameter through the formula. You can also use the size jitter value to control the minimum diameter. So why is there this "superfluous" option?
Let’s put this question aside for a moment and let’s draw three straight lines.
First line: Set the brush diameter to 10 pixels, spacing 150%, roundness 100%, and size jitter 0%. Control off.
Second straight line: Based on the first setting, enable the "Control" option under the size jitter, select "Fade", fill in the following number with 20, and the minimum diameter is 0%. As shown below on the left.
The third straight line: Based on the second setting, set the minimum diameter to 20%. As shown in the middle picture below. The drawing effect of three straight lines is as shown on the right, arranged from top to bottom.
What is going on? First understand what fade out is.
Fade means "gradually fading", which refers to the process of change from large to small, or from more to less. It is a state transition. Just like drinking a drink from a cup, the process of drinking is equivalent to the fading process of the drink.
Now looking at the first line, that setting actually makes the entire Shape Dynamics option useless, since it doesn't have any effective controls.
The second straight line turns on the fade control, which means that it "gradually fades" starting from the size of 10 pixels. To what extent? to 0 pixels. So we see the brush dot gradually shrink until it disappears completely.
So how to control the length of this fade? It is the value 20 filled in later. This 20 represents the step size, which means passing through 20 brush dots. You can count them carefully.
The third straight line turns on the minimum diameter control. 20% of 10 pixels is 2 pixels. At this time, the fade option cannot completely hide the brush. The minimum value of blanking is 2 pixels. The step size is still 20 steps, so the transition from 10 pixels to 2 pixels is 20 brush dots. After 20 brush dots, the size of 2 pixels is maintained, and these 2 pixels will never fade.
You and your lover dine at McDonald's and buy a can of drink, then:
If you are not interested in this can of drink, you have never touched it from beginning to end. That's like the first straight line.
If you are salivating over the can of drink, drink it quickly while she or he goes to the bathroom, leaving only an empty glass. That's like a second straight line.
If she (he) carves a mark on the cup to tell you that the level of the drink cannot be lower than this mark when she (he) comes back, it means that your lover knows you too well, and you can only be like the third straight line. Control your own limits because of the other person's foresight.
The process of you drinking a drink is the fade-out, the time you take to drink the drink is the step length, and the mark carved by your lover on the cup is the minimum diameter.
In addition to fading, you can also use pen pressure, pen tilt, pen wheel, and rotation to control size. These three options require additional hardware. The picture on the left below is the effect of drawing with pen pressure. The so-called pen is an input device called a digital drawing tablet. Use an electronic pen to move on the matching base plate instead of a mouse. As shown below on the right.
The bottom plate can sense the strength of the pen tip contact (in layman's terms, it is the difference between the light and heavy strokes), and advanced drawing tablets can also sense the tilt of the electronic pen and the rotation angle of the pen tip. These effects cannot be simulated by ordinary mice. The light pen wheel refers to the thumb wheel attached to some electronic pens. Without this device these controls have no effect.
Note that the pen mentioned here is completely different from the vector drawing tool pen we will use in future tutorials.
