How do I make an object's shadow length same as its height

We know, if the altitude angle of the light source to an object is 45°, then the shadow length gets equal to the object’s height, we follow this when we draft shadows in 2D, but how do i customize shadow like this in sketchup? ive tried manually changing time and season but it doesnt give the exact result, ive tried getting info from chatgpt (like the altitude, longitude, azimuth, altitude angle, time and season) but there’re no options to input all those values in sketchup, also tried with the curic sun plugin but this too doesnt let the azimuth and altitude angle to customize. Can anyone help?

How accurate do you need it to be?
Here’s a simple way to deal with it and zoom in on the spot where you can manipulate the shadow sliders to create the shadow touching one of the two circles (or the dashed tangent guide in between). Multiple options depending on time of the year and the day.

p.s. the block height is 3000 mm

Maybe TIGs 45° Shadow Plugin.

2.skp (317.8 KB)
uh, i could zoom in and draw the shadow the way you showed, but uh, i provided the skecthup file, can you take a look? the way we draw shadows in 2D,i drew the shadow plane there and they DONT MATCH, and i cant zoom in to manipulate the shadow sliders to match the shadow plane i drew, i dont know why.

You’re using the web version of SketchUp for school children? That’s what your profile says, anyway. In that case it’ll be a bit of trial and error to get the shadow placed exactly where you want it. If you were using the desktop version, I think Mike’s suggestion is good.

i tried the plugin, uh in some way, it doesnt work still, the shadow the plugin generates fall short, you can check the file above

Is there a reason it must match ‘the old way we did it in 2d?’

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not the way, but the shadow should be identical, right? Im just trying to make the shadow be the same as it’s height, how come i cant do it!

I think because you haven’t set the correct latitude.

Since you aren’t actually using SketchUp for Schools, please correct your forum profile.

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Sorry for late and uh for that, here ,
2.dwg (121.1 KB)
can you kindly open the cad file, this is what i exported as 2D shadow plane from sketchup, all the hassle for this, now if you look at the cad this isnt accurate, the top one is the actual shadow done in cad(you can see both lines in x and y axis are 100’) , but the bottom one (the way you told to do) isnt really accurate, thats the problem, its not accurate. Just any way to make this accurate so I can just export to CAD and ease out my workflow?

Well, I set up to do this by making a cube and deleting all but three sides. Match the shadow from the upper left near corner to the lower back corner by playing with the shadow sliders. There’s a slight imperfection, but maybe less than an inch in 8 feet.

Edit: I did a post on this back in 2018 here.


Thanks, i wish there was a way to do this fast, in a complex model its gonna consume a lot of time(with imperfections), i think i’ll just head over to CAD and do the shadows there, thanks everyone:)

I used to make a component out of my building, and have copies on their own special Tags each with the face in question facing negative green direction, but since then, I’ve learned to control north with scenes IF animation is turned off. Now I have a template I made that has 45° shadows for every plan, section, and elevation drawing all set up.

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