You will find the shortcode_portfolio_carousel method in includes/shortcodes.php
It is generally a more restrictive shortcode, in the method you will find it’s title: __(“Portfolio Items”, “Aqua”) and you can change it there.

It doesn’t allow category param out of the box.
Now you can use the posts_carousel instead where you would pass “portfolio” as post_type param and then you can pass the category_slug that you want to filter by and number of items etc. It looks a bit different though.
You can modify the portfolio_carousel to accept those params as well if you follow the pattern in the code from the shortcode_posts_carousel method and add it into the shortcode_portfolio_carousel if you know your way around some coding.
I could also give you a hand if you want to go that way. Good luck!

Also, is it possible to change the links of the post items? I was hoping to link them to pages instead of the portfolio posts pages.

I tried to copy and paste the html that the [posts_carousel] shortcode renders on the page, but the slider function would not work as well as the SPAN tag in the title. SPAN tags are dropped for some reason.

It’s always possible to use redirects in htaccess file, but I was hoping to avoid that.

Thank you,
Charlie

What would those pages be? Are you not going to use those portfolio items at all? Just for creating a carousel? Yes, I have done it similarly with redirects before, use a plugin instead of htaccess for easier management.

https://wordpress.org/plugins/quick-pagepost-redirect-plugin/

Another related issue…
How can I rename http://domain/portfolio_item/item/ to http://domain/products/item/?
Since I’ll be using portfolios as the product page I want the url to reflect that.

Than you!