how to show flood height?

[juliamachin]

I am hoping to show the simplified impact of different flood heights in my scene. I have a polygon that covers the extent, and I would like to be able to extrude it to a specified water height. However, I'm not sure how to make my polygon sit flat at 0 metres to start. The terrain in my scene starts at -1.5m, and I don't know if my polygon is starting from here or zero elevation or something else.

Right now my code looks like this:

Start -->

    alignScopeToAxes(y)

    s('1,0,'1)

    extrude(floodheight)

    color (watercolour)

Is this correct? Do I need to add/change/remove anything? Thanks!

[Anonymous User · Accepted solution]

You said you are "not sure how to make my polygon sit flat at 0 metres to start". Don't use the rule for this part. Just select your polygon. Right-click and select "align shapes to terrain". Choose "Project All", and heightmap "y = 0". That makes your polygon sit flat at 0 meters.

Then your rule becomes:

Start -->

    alignScopeToAxes(y)

    s('1,0,'1)

    extrude(floodheight)

    color (watercolour)

And rather than extrude, you could alternately use translate() to just move the polygon up.

Also, you can add this for transparency:

set(material.opacity, 0.5)  # use value between 0 and 1.

[juliamachin]

Thank you!