How does Craft know when to generate an Image Transform

Question

I created an image transform called teamImage. My template code is below.

I want this transform to be created when I upload an image within a Team entry.

Team has it's own asset folder.

My questions is how does craft know when to create this transform and where in the directory does it create it?

{% for asset in entry.teamImage %}
    <a href="{{ entry.url }}">
         <img src="{{ asset.getUrl('teamImage') }}" alt="{{ asset.title }}" />
    </a>
{% endfor %}

Answer 1

Craft will make the image transform the first time the template is loaded in the browser and the getUrl() is called. The image will at first be saved in a temporary directory, then moved into a sub-directory in your assets folder. The subdirectory will be descriptively named according to the type of transform. For example, if my template calls for a 500 x 500 center-center crop at 75% quality, it will be saved in /uploads/_500x500_crop_center-center_75/img.jpg.

This works similarly when using a CDN like S3 or Google Cloud.