I use sketchup to create landscape designs remotely.
One of the useful things about sketchup is that I can geolocate and cast shadows onto the model.
Plants need specific amounts of sunlight in order to thrive.
So this allows me to plan gardens without needing to do any site visits (they’d be impossible as my projects are all over the country) as I am able to distinguish the levels of sun that the different areas of the garden gets.
Someone told me that the sketchup sun isn’t accurate. Is this true? I need it to be accurate.
If not, is there some extension or plugin that would be helpful to me?
It’s not 100% accurate but it’s accurate enough to make a light analysis, you can use the solar north plugin also if you don’t want to rotate your model. You can also use pre design included with a pro subscription, it’s pretty useful for light and wind analysis.
they can be quite correct. more so for a “global” approach. if you want to know if your living room will see the sun in winter, it’s fine. if you want to know the exact precise shadow on may 17th at 16:18 then chances are you won’t have the actual real life shadows.
you need 3 things :
a proper location. latitude, longitude, north. well on that end, the new geo location tool allows you to rotate the north and show it to you as an orange line.
an environment. you need things that will cast shadows on your model. trees, buildings, signs…
a time zone. I find I get better results using the “solar” time zone and not the political one. France is below england and shares the same “slice” of earth. but uses east german time.
since you’re picking a time zone, you’ll have a imprecision there. time zones, even solar ones, are wide. it means that depending on where you are you can have a difference of sunrise/set of about 1h with other places.
I’m in Marseille, in south east France. my mum is in Guérande, north west. we have about 45min of difference when it comes to the sun. but for sketchup, we’re both in the same time zone.
My experience is that ‘Add Location’ has effect by roughly 2 minutes for two locations only 40 km appart. (checked for December 2025, where I live < v.s.> 40 km to the east)
Of course one can better check by using specific longitudes where 360 deg. = 24 houres.
I did a very simple test.
I created a model with a scene geolocated to my boat and saved that as model 01.
Then geolocated the model to my brothers house over the other side of Sydney, approx 45km as the crow flies, 70 or so by road, and did Save as to model 02.
2d output from each gives two images, when viewed as a gif watch the point of the shadow.
Were they both the exact same latitude ?
Variations on a north-south scale do matter, and make shadows shorter or longer (like in your gif). It’s the east-west I’m curious about.
changing the longitude, even by small increments, slightly changes the shadows.
still, I’m making changes of about 5-10km, and the changes are small enough to not really be relevant. chances are, the exactitude of your environment will matter more. But it’s a good thing to know.
today I learned.
I’m gonna stop there, too much learning for a saturday
