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.
there are some very easy steps to make such triangle with round corner with the help of pen tool, and its from scratch too
add additional anchor point at the bottom corner right and left both side according to attached screen shot.
after that press A / or select (path selection tool)and move it slightly to the right side you can bend it according your desired round shape, apply the same thing at the top corner there you have to add only one anchor point and do the same as you did in bottom.
turn on the grid (Ctrl/Cmd-,) it will help you for placing anchor points for exact round corner/radius for both side, you can increase/decrease your radius just by dragging anchor points.
check this SS....
(left click and view big image in new window)....
Hope this will help...
Create a triangle with the pen tool. Using effects, put an outside stroke on it, making it as large as you need for how rounded you want your corners. Now you will need to smooth any points in your stroke by following the next steps.
Right click on your triangle layer and choose Convert to Smart Object. Holding Ctrl, click on the thumbnail of your triangle in the Layers panel to select it. Go to Select in main menu and choose Modify, then in dropdown choose Contract. Contract by 3px. Go back to Select in the main menu and again choose Modify, this time choosing Smooth, and enter 10px. Hit the mask button at the bottom of your Layers panel. Go back to your layer and right click, choosing again to Convert to Smart Object.
Depending on the size of your triangle, you might have to change how many px you contract and smooth when making your selection.