Pick a point, get a number

I was staring at a Forma terrain the other day, trying to eyeball whether a pad grade was close to code. The site was right there, turning in front of me, and it told me nothing about grade. Terrain you can see is not terrain you can check.

So I built the color. Then I built the number, because the color turned out not to be enough on its own.

What it actually does

Pick a point on the terrain. The extension casts a ray straight down from your pick. Wherever that ray lands, it reads the triangle's face normal and turns it into a slope percentage.

That's it. One point, one number, dropped back into the Forma viewport as a marker so you can see exactly where it was measured.

The marker does not have to report slope. Flip it and the same pick reports elevation instead, because the ray already knows where it landed. Same click, same marker, different question answered.

Two ways to paint the same surface

The same choice exists one level up, on the terrain itself. The surface can render as a slope heat map, a wash that runs warm where the grade steepens, or as an elevation banding map that groups the site into steps by height.

Neither of those was sitting there waiting to be switched on. Forma gives an extension the hook to lay a texture over the terrain, which is the part I did not have to build, and the map that goes into it is mine. No second model, no export, no round trip either. The triangles are already in memory from the pick work, so recoloring them costs almost nothing.

The two maps answer different questions. The heat map shows us where the grade breaks. The bands show us where the high ground is and how far the low corner really drops. We pick whichever one matches the question being asked in the room.

The same values, as a list

Both sides of that switch also have a table view. Slope or elevation, the values that drive the colors are listed out where we can actually read them.

A map is for scanning. A table is for checking. When someone asks which band a pad falls in, or wants the readings written down somewhere other than a screenshot, pointing at a color does not settle it. The list does.

Why the number matters more than the color

A heat map is good for spotting the steep corner of a site from across the screen. It is bad for telling you whether that exact corner is 4.9% or 5.1%, and code does not care about "close."

We already trust the color to say "look here." We should not trust it to say "you're fine." Those are two different jobs, and the extension keeps them apart on purpose. The map does the first one, in slope or in elevation. The marker does the second one, in slope or in elevation. Know which one you are looking at before you sign anything.

Be Better - Trust the number, not the color.