is there a way to get a world texture to affect the objects but not show in the background of the render?
Well, if you use an image format that supports alpha, then just rendering to ‘premul’ and ‘rgba’ will allow you to render an image containing only the objects, not the world. The reflections, etc. should still affect the objects.
no idea what any of that means, hah! not quite sure how to change the format to be honest, I just know how to save render as jpg which is super easy.
In your Render Panels under ‘Format’ (F10), choose PNG from the image format drop down where it defaults to saying ‘jpeg’, then click ‘rgba’ underneath that. Over to the left you’ll see another panel marked ‘Render’ and you can choose ‘Premul’ ther to use Premultiplied Alpha. If you then press F12 to render, you will see a render containing only your objects, not the background world space. This you can save with F3 and open in the image editor of your choice (easiest is Blender’s UV Image editor) and see that the background is rendered transparent.
Hope that helps.