Hacker News

70 points by fredley 6 hours ago | 20 comments

This is great. I would love a way to simulate something like possible tree placement and how much shade that may generate over the years. There are some parts of my area that are, despite being cut out of a forest, devoid of trees but are supposed to be "outdoor shared spaces".

Full sun all day at a dog park in August, for example, just isn't a place I want to be.

tppiotrowski 2 hours ago

Site maintainer here. There is a polygon drawing tool in the upper right corner of the map. You can use it to draw polygons on the map and assign them a height. The shadows will update instantly. You can use it to add buildings that are missing from the map, simulate a tree placement or even simulate cutting down a tree if you set the height to 0.

illithid0 29 minutes ago

Wow! Can't believe I missed this. Thank you.

jborichevskiy 28 minutes ago

I've wanted something like this - in Boulder the foothills cast a shadow on the town considerably earlier than sunset provided by weather apps. So in theory, this should be possible to figure out when a park will actually see a sunset. Nice work!

culebron21 10 minutes ago

I see only a grey rectangle and a hand cursor.

deckar01 53 minutes ago

Trees should not cast shadows as if their foliage extends all the way to the ground.

tppiotrowski 29 minutes ago

Agreed. From current data it's not possible to know the type of tree, only their locations so the model is simplified.

foco_tubi 3 hours ago

This doesn't look particularly accurate, at least not relative to what I can see right now out my window.

tppiotrowski 2 hours ago

Website creator/maintainer here. Happy to try and diagnose the error if you elaborate on what the discrepancy is (tree, building, hill, etc)...

Gallows4574 2 hours ago

Very cool tool! It's generally accurate, but, there are spots showing shadows where there are no trees or anything at all to cast a shadow, and missing several spots where there are actually trees.

It's missing a 40' tall ash, a 40' tall maple, and all four 30' tall blue spruce. So they're not exactly small trees. Our septic field is showing as in shadow all day even though there are no trees near it. That shadow doesn't move at all like the rest so I'm not sure what it's detecting.

tppiotrowski 54 minutes ago

Sorry about that. The current tree estimate is done via computer vision but I am working on migrating to LiDAR backed data which should eliminate false positives.

Just waiting for the TBs and TBs of data to download and then this Macbook M4 is going to make some heat...

foco_tubi 2 hours ago

Hi there! My office window faces east and this morning, your map showed shade from the building across the street (correct), as well as shade from my building on the lawn below my window (incorrect).

tppiotrowski 2 hours ago

Thanks for the reply. Do you have a tree or bush outside your window? I estimate where tree shadows fall but it's not super accurate. In the settings dialog you can toggle, "below canopy", "above canopy" or disable tree shadows altogether.

pavon 3 hours ago

Be sure to check out the different layers. In addition to the default which shows shade at a given moment, there are also options for hours of sun in given day, and an a UI to quickly show shade at any day/time of year.

allthetime 51 minutes ago

https://app.shadowmap.org

Has has existed for many years

waterpowder 5 hours ago

It reminds me of this nice website for when you want to have a drink in the sun at a terrasse in Paris :D https://jveuxdusoleil.fr/#16/48.8551/2.3479

cactusplant7374 4 hours ago

This is interesting. Have you used it to find a nice place to have a drink?

waterpowder 4 hours ago

Yes, although those days I tend to prefer places in the shade, or inside with AC...

4corners4sides 4 hours ago

Does this handle eclipses

tppiotrowski 2 hours ago

Not specifically for eclipses but has been useful in finding places where the sun will be visible during the current eclipse since the eclipse will occur when the sun is quite low on the horizon.