Ever thought of a craggy rock entrance to the cave....Kinda like going in and out of a mine?
Regards,
~B

Yes, that is kind of what i tried with the existing image, but it didn't really turn out good :)
also i want a smaller entrace too, maybe it could look like that, haven't really decided yet.
probably i need some more practice though :)

Organic shapes are hard! Here is a more rocky mine entrance, releasing image under same UNLICENSE as this mod for use however.

https://www.dropbox.com/s/yj333mqbgc3dnsu/Screenshot%202017-07-17%2003.32.14.png?dl=0

https://www.dropbox.com/s/luceio8gg6q12nw/mine-entrance.png?dl=0

I have this as a blender project so can re-export at any resolution or change colors/shape easily.

Edit: Blender Project Link https://www.dropbox.com/s/r5296pqo1vb0r94/CaveEntrance.blend?dl=0
Credit: blender project contains some base game belt sprites, and is derived from some mish mash of this forum thread: https://forums.factorio.com/viewtopic.php?f=34&t=5336, some issues with shadow generation, I need to reorganize the project.

Looks quite a bit better :) i like the wood beams, makes more sense than straight up rock. Also i tried to have a non-flat surface, but the material made didn't really show that. Yes the project might be helpful (i would tweak the sizes a few pixels so it aligns to the grid)

thanks for sharing, i probably take a look over the weekend to put together another version.
for shadows, all i can say is that it depends on how far you want to go.
for another mod idea i was playing with i needed better lighting in general so i switched to the cycles renderer (and sticked to that since it works now). out of the box, shadows then don't work correctly.
i was using a patched version (https://developer.blender.org/D1788) where you can set up a plane to be a show catcher, so all the shadows are rendered into it.
maybe it is part of the experimental builds by now, but i am not sure; the 2.78c version probably still doesn't have it.
just fyi :)

Yep, shadow catcher is in daily builds!

https://www.dropbox.com/s/q4ggkx6cjp3bdt3/mine-entrance2.png?dl=0

Slight tweak to alignment / colors / shadows:

Updated game graphic: https://www.dropbox.com/s/4uwv2pf12iecj8w/mine-entrance.png?dl=0

Updated Blender Source: https://www.dropbox.com/s/uefci874rd5srao/CaveEntrance2.blend?dl=0

Thanks, looks quite nice :)
i have integrated it into 0.1.5; sorry for the delay
unfortunately didn't have as much time as i hoped to get more into blender