Generate masks from polygon drawn in the orthophoto

[Guillaumeb89]

Hi,

I would like to know if its possible to generate a mask for each photo in my chunk, from a polygon that is drawn on the orthophoto.

The idea is to mask every watered zone then regenerate clean models with my photos and a mask applied for each of them

regards,

[Paulo]

Guillaume Bonjour,

I think this can be done by developing a script. From the polygon on ortho you would need a DEM to apply the altitudes to each polygon vertex. Then find its  projection on each corresponding camera and generate a mask...

You can send me a PM for more details...

[Guillaumeb89]

Hi Paulo,

Thank you for your answer

That's exatly what I tried to do.

I'm using a DEM for polygon projection.

I managed to write a script but I'm blocked when I have to reproject the polygon, especially when the polygon appears in partially on the picture ..

I'll send you a PM

regards,

[Alexey Pasumansky]

Hello Guillaumeb89,

As a possible workaround, if you already have DEM: build mesh model using DEM as a source surface, crop it by the shape that you need to use as a mask (set as boundary, then duplicate model with "clip by boundary shapes" option enabled), then run Generate Masks process using "From Model" option.

Probably, before clipping the model by shape you can also smooth it using high Strength value (like 50 or even 100) to make the surface almost flat, if it is related to the water only.

[Guillaumeb89]

Hi Alexey,

Thanks a lot for this useful answer. You solved my problem !