topic Shadow diagrams plan in Visualization

Shadow diagrams plan

eddy007 — Mon, 08 Sep 2025 01:49:28 GMT

Hi, I have a problem with the shadow diagram study in plan.

I want to show both the existing building shadows and the proposed building shadows on the same plan, but the elements I plan to demolish don’t cast shadows.

Can you suggest why this happens and also make a video showing a more modern way to do it? I have the impression I’m doing it in a very old-fashioned way.

Thank you!

Operating system used: Mac Intel-based

Re: Shadow diagrams plan

eddy007 — Thu, 11 Sep 2025 05:41:29 GMT

Any advice?

Re: Shadow diagrams plan

Barry Kelly — Thu, 11 Sep 2025 05:44:43 GMT

If you can't see an element, it won't cast a shadow.

You would have to show the demolished elements, cast a shadow and copy it and then paste into your plan.

Barry.

Re: Shadow diagrams plan

graava — Fri, 12 Sep 2025 02:21:47 GMT

You need 3 drawings (views) to achieve this.

First, create a floor plan view. For this desired diagram a rooftop view would be the most suitable.

Then create a 3D document from a top view with the parallel projections. Save two views with different settings for this 3D document. You'll need to assign the "Planned status" renovation filter for one view and the "Existing plan" to another. Be sure that the scale for these 3D documents is the same to your rooftop plan.

Here's a screenshot of my 3D document settings for the shadow display:

The white pen will make sure you won't have any undesired lines in your final plan.

If you need to move the shadows position, adjust them on the 3D model and redefine the 3D document.

Finally, create a new layout and place your 3 views in this order: (top to bottom):

Rooftop floor plan view
3D document with "Planned status" renovation filter
3D document with "Existing plan" renovation filter

Adjust the drawings position so they get aligned correctly.

Re: Shadow diagrams plan

eddy007 — Mon, 15 Sep 2025 05:26:59 GMT

Hi Barry,

The problem is that I create the shadow with the demolish and existing model, but then when I copy and paste it as a fill onto the new model plan, the shadow from the demolished elements doesn't appear. An error window then notifies me of a problem.

Thank you heaps

Re: Shadow diagrams plan

eddy007 — Mon, 15 Sep 2025 05:27:56 GMT

Hi Graava,

Thanks you heaps for your detailed reply. The problem is that I create the shadow with the demolish and existing model, but then when I copy and paste it as a fill onto the new model plan, the shadow from the demolished elements doesn't appear. An error window then notifies me of a problem.

Thanks

Re: Shadow diagrams plan

Barry Kelly — Mon, 15 Sep 2025 06:09:23 GMT

So you do a 3D view of your building with the shadows on and all reno status showing.

You 'look to perpendicular' to get a plan view.

Change the 3D style to 'Basic" so you can place a marques and 'Copy' the shadows.

Now you can paste the shadows into your plan and align them with your building.

You will want to make sure all of the fills are pasted as 'Existing' or a reno status that is showing for the plan that want to show the shadows on.

You could change the fill colour for new, existing demo if you want.

Barry.

Re: Shadow diagrams plan

graava — Mon, 15 Sep 2025 16:06:40 GMT

You don't need to copy and pase anything. What you've got with the 3D documents is a live view from your shadows that will update with any change.

Here's a video:

Final result (blue - new construction, red - demolition):

Re: Shadow diagrams plan

smaarchviz1 — Mon, 22 Sep 2025 14:15:40 GMT

The reason your demolished elements don’t cast shadows is that once they’re marked for demolition, the software excludes them from calculations like shadows. To show both existing and proposed shadows, either duplicate the existing building on a separate layer/design option so it still casts shadows, or create two shadow diagrams (existing and proposed) and overlay them with different colors or line weights.