I am trying to work out shadows on a real life location but the settings in my Shadow panel seem more limited than normal. Depending on the date I set, the earliest and latest times in the day shifts. I would assume this is based off what sunrise and sunset is, but the shadows still look like they have some way to go before sunset at the latest time available.
I have geolocated my model to the correct world position, do I need to get rid of this to be able to extend the time range on shadows?
Make sure you have set the correct timezone.
Hi Box,
I have the correct timezone and the correct location, but when using terrain with hills it becomes very apparent that the shadows still have a way to go. In the scene that I have loaded, the shadows on one side of the valley are 8m lower than the other side of the valley at sunset, there seems to be no way for me to simulate the shadows in the time after that.
Perhaps if you added your model someone could see the problem.
I am not able to share the working model I have for work reasons, but the same issue can be replicated by bringing in a mountainous region’s geometry and adjusting the time and date settings.
The location I have been using is based in Gran Canaria, off the west coast of Western Sahara. I am interested in the shadows throughout November, so the time zone is GMT+0 at this date.
Ideally, I would like to be able to set the time of day to night time through to night time and get a full range motion of the sun.
It is possible that the heights of the mountains in the geolocation terrain were interpolated from a coarser grid. Have you cross-checked them against a known accurate topographic map? It could well be that the data SketchUp gets is not accurate enough for what you need to do.
One issue here with freely allowing time selection is that shadows on the ground won’t work correctly when the sun is below the horizon.
The time picker is therefore limited to sunrise-sunset, and if you get too close, SketchUp stops displaying shadows, to stop this from failing.
I tried in Gran Canaria, and with a 60m tall tower projecting shadows onto a 60m “cliff” 500m away, at sunrise I can see the shadow is 0.6m below the top of the cliff. Every second that the time is changed (using the ruby API), the shadow top moves by about 0.04m.
It would therefore seem that the time at which SketchUp stops showing shadows in this location is 15s after sunrise, which is the bit you are missing (the panel only lets you choose within 16s of sunrise there btw).
This is the ruby I used:
model = Sketchup.active_model
dt = model.shadow_info["ShadowTime"]
model.shadow_info["ShadowTime"] = dt + 1