I know you can create a rounded-corner rectangle; but, how do you create a triangle with rounded corners in Photoshop?
I am actually interested in making it from scratch, not basing it on a custom shape that is available in Photoshop. Thanks.
There are several ways to do this. You can use the pen tool draw it yourself.
My answer is based on the way I’ve been doing it over the years.
Draw a triangle in a new layer. hit cmd+a(select all) then cmd+c(copy)
switch to the Channels tab and create a new channel. It will be named “Alpha 1” by default. now paste the triangle you copied from before. Note the triangle will be white. The white area in the channel will become your select mask later.
now give the entire channel layer a Gaussian blur. note: the blur value here won’t translate exactly to the pixel border radius you want. you’ll just have to play with it a bit. I’m using 10px blur in my example.
After you’re done blurring, hit cmd+L(level). In the level menu, adjust input values. use the value I picked in my screenshot. The idea is to get the triangle “sharp” again. Doing so will create the circular tips on each end.
Now go back to the Layers tab, hide the triangle layer you drew from before. start a new layer, then to go “Select” -> “Load Selection.” In the popup, for “Source” choose “Alpha 1”
Now you’ll have the rounded cornered triangle outline selected, you then can fill it to whatever color you like.