How to use the Photoshop custom shapes / settings panel options for the Photoshop custom shapes such as define, constrained, from center etc. You can select the custom shapes options / settings by selecting the shapes tool in the toolbar and then going up to the top bar and text to the shape dropdown you will see the shapes options / settings panel (little gears or cog). Click that and you will see the shape options / settings such as defined proportions, defined size etc. You can then select one and use all the shapes in that way. The fixed size sets the shapes all to a particular size (say 10cm by 10cm). Defined size is useful as a shape option if you have a set size for all your artworks (that they must be drawn at 10cm by 10cm etc say in technical drawings etc). You can use a defined proportion so everything is always 1:2 or 1:5 etc. You can also draw the shape from the center as a shape setting / option. This tutorial shows a number of ways of using the shape options / settings for Photoshop custom shapes
Select the custom shape tool
Go to the top bar of Photoshop (custom shapes options)
Go to the shapes (little gear) settings
Select fixed size (say) and set width and height for the shape
Apply the shape with a fixed size (and not unconstrained as default)
The Photoshop custom shapes are displayed via the presets panel (on selecting the CSH tool). The panel can hold a large range (though not every shape created on graphicxtras) as thumbnails. To use, simply select the shape. The presets panel can also be added to via the standard file menu and open command as well in later versions of Adobe ® Photoshop ®and Elements.
To use the Photoshop custom shape options / settings, you must go to the little gear
Click the gear option / settings button on top bar
Select unconstrained, defined proportions, defined size, fixed size etc
There are additional items associated with the custom shape tool such as apply the shape as
Select custom shape tool
Select defined size (set size as required)
Go to the document
Click and repeat click to add the fill over the entire document (great for a nozzle like effect for shapes)
The defined proportions applies the artwork as defined the proportions set by the original shape before being saved as a custom shape. Great for keeping the presets in proportion to one another.
So if you have a custom shape with a size of 10px by 10px, you can then set it as 100px and 100px or 200px and 200px or 2px and 2px etc and they will all be in that proportion.
If the custom shape was created with a size of 100px (horizontal) and 200px Vertical) then any created custom shapes using the panel options in Photoshop will be 10px / 20px or 30px / 60px etc
This just uses the custom shape as was originally set which may be of little use if the created size was quite small. Many of my custom shapes sets were created with documents sized about 300 x 300px which means that the defined size sets them to around that value.
Still, it is useful for adding the shapes with a set size that you may have defined for a particular project such as perhaps having a building size or architectural item or an engineering shape set to 1000px and 500px and then whenever you use it in your projects, the defined size command adds the artwork exactly to that size.
The fixed size panel option is useful for a nozzles like / brush apply of the shapes. You can set the fixed size to 100px by 100px etc and all the shapes will then be applied (whether in proportion or not) the same size over and over by a click of the document. You can also drag the shape into position. It is a pity there is no 'pressure sensitive setting' so the fixed size can be increased or decreased based on the pressure to the maximum set 'fixed size' (perhaps something for Photoshop CC 2020 ?)
The default option and possibly the easiest to use to apply the shapes as you want and in any position or proportion. The options work with all the shape types as well.
Go to the custom shapes settings / options panel
Apply the shapes and stretch and distort left and right and top to bottom
Probably the oddest one to work with as it just creates the artwork from the center (click) outwards.
A quick tutorial showing some of the Youtube video : panel options in Adobe ® Photoshop ® [Youtube]