Planivolumetric

mitcorb

@Antonio83:
Yes, that is one of the images I saw in Google while looking for the word.

Openspaces

Hi, for the shadows, instead of the parallel projection, i think you should use the perspective and then put the shadow tab on in sketchup. You can then play with the time and period of year.

brodie

@unknownuser said:

Hi, for the shadows, instead of the parallel projection, i think you should use the perspective and then put the shadow tab on in sketchup. You can then play with the time and period of year.

The parallel projection is just to get the type of view portrayed in the image above. It has no affect on shadows. If you do the shadows by hand, I'd place the model on the equator via the Model Info window and set the date to June 21st. That should help get you pretty linear results as you adjust the time and North direction to get just the right shadow positions.

-Brodie

Antonio83

Let me explain.
I have to draw a floor plan with the shadows.
The shadows should be at 45 degrees and the length shall be equal to the height of buildings.
For example, if a building is 5 meters high, the shadow line of 45 degrees must be 5 meters long. In this way I can measure the height of a building by calculating its shadow line
I intend this to "planivolumetrico"

Now, there is a plugin that allows me to do this?
It 's strange that this plugin does not exist in SketchUp ...

Dave R

Anotonio, see if this will help.

Antonio83

I already know this plugin (Elev45Shadows.rb): it makes 45 degree shadows but lenght of shadow line is not equal to the height of building.

I tried to set up shadow settings, but happens that inclination of the shadow line changes

brodie

For what you're doing that plugin should be what you want. I'm a bit confused as to how, you've got 45 degree shadows, yet the shadows aren't the same height as the building. Could you post some screenshots so we can help you fix that issue?

-Brodie

Antonio83

@unknownuser said:

I'm a bit confused as to how, you've got 45 degree shadows, yet the shadows aren't the same height as the building.
-Brodie

I think you're right...
Using this plugin, I realized that shadows are not at 45 degrees.
Maybe I do not use it properly...

I click on isometric view and then click on View > Elevation 45 shadows

this is final result: shadows are not at 45 degrees (blue line is at 45 degrees. Its lenght is 5 meter and it is equal to the height of the solid)

This is my Model Info settings

brodie

Well, I've found part of the problem. Even when used properly the plugin doesn't do quite what you're wanting it to. It should do 45 degree angles but it makes your dimension the long side of the 45/45/90 triangle. The image below illustrates this along with illustrating the dimension that you WANT the shadow to be (sorry for the english units )

Here's my workaround. It's not a perfect solution, but it will probably be good enough for what you're doing and only works in plan view (because effectively what you're wanting to do is raise the sun higher in the sky so in elevation the shadows will point more towards the ground. Basically, just run the plugin normally and then change the shadow settings to match these.

As for how to run the plugin. you want to have parallel projection turned on (ie. don't be in perspective camera mode), and you want to be looking straight at one of your wall faces. You can just pick the standard views if your building is aligned square with the SU axis. Otherwise, select a face, right click, and select Align View to Face. Then run the plugin. If the shadows aren't pointing the right direction you can go to Model info -> Location and adjust the North direction of your model in 45 degree increments until you get them pointing correctly.

I should also note that I think the way the plugin is setup natively is the 'correct' way it should be represented architecturally (ie, you don't want the angled measurement to be the same as the building), at least as I learned it in school. You may just want to double check and make absolutely sure this is how you want to do it, if this is for school or something.

-Brodie

Dave R

What if the latitude is set to 45°, the time to noon and the date to 21 September or there abouts?

Antonio83

@unknownuser said:

Here's my workaround. It's not a perfect solution, but it will probably be good enough for what you're doing and only works in plan view (because effectively what you're wanting to do is raise the sun higher in the sky so in elevation the shadows will point more towards the ground. Basically, just run the plugin normally and then change the shadow settings to match these.

Ok, I did as you told me. I managed to solve this problem
I thought there was a more immediate solution, but that's okay

Thank you very much:)

Gaieus

@dave r said:

What if the latitude is set to 45°, the time to noon and the date to 21 September or there abouts?

That should not work as the shadow would point to North

Dave R

@gaieus said:

@dave r said:

What if the latitude is set to 45°, the time to noon and the date to 21 September or there abouts?

That should not work as the shadow would point to North

Of course. So what time is half way between sunrise and noon at on 21 Sep at 45° N latitude? That ought to give the right shadow.

Gaieus

That would give longer shadows though. So ideally you should have the shadows at 9 am or 3 pm (15:00) - depending which direction you wish them to see) and have to fiddle either with the date or with the latitude (or keep it at the equinox to have an easy starting point) and only change the latitude to something I am not really willing to count now.

Gaieus

No, this is not working. It's either not the same length or not at 45 degrees. I'll leave it to someone more knowledgeable.

Dave R

Oh come on. You can do it.

I wonder how hard it would be to create a plugin that would

A. Copy the footprint of the selected building(s)
B. Move the copy of the footprint 45° say to the northeast or northwest and place it some small distance above the ground plane to prevent Z-fighting.
and
C. Fill the outline of the foot print with a transparent gray face.

In order for what Antonio wants to do to be useful, the ground must be flat so there'd be no need to make allowance for terrain. The image output would be a 2D top view so the resulting faces could be at any height above the ground. Perhaps they would be placed at the height of the tallest building so that it appears that they are casting shadows on lower things. Or maybe each "shadow" face could be placed at the top of its building.

It's easy for me to do all this free thinking and come up with ideas since I have no idea if they could even be implemented.

Dave R

@gaieus said:

No, this is not working. It's either not the same length or not at 45 degrees. I'll leave it to someone more knowledgeable.

It's probably due to the Earth being round instead of flat. We could blame Christopher Columbus. He's not here to defend himself anyway.