hello I'm Marc Desgroseilliers from technical
support here at Pix4D and today i
will talk to you about orthofacades.
What do we mean by orthofacade well it's an
orthorectified image of the facade of a
building or any other object in your
project which is more or less planar and
this is a concept which is going to be
familiar to you if you know what
an orthomosaic is. If you don't know what
an orthomosaic is, then I encourage you
to have a look at one of our other
videos where we talk about the mosaic
editor. So basically your orthomosaic
is going to be generated always from the
top down whereas the auto facade, it
gives you the possibility to change this
orientation and so, to generate the
orthomosaic of the facade of the
building for example. You're going to be
able to change the orientation by
inserting and orthoplane object in
your project when you insert the ortho
plane you should make sure that the
green arrow is always pointing towards
the facade of the building, as in the
image that you see here you can also
adjust the size of the of the orthoplane
by adjusting the red blue and
green balls for the different directions
One tool that we have in the software to
improve the output and t o improve the
orthofacade is the annotation tool
this will allow you to remove some
background from your orthofacade so let
me give you an example: let's say
your project is a church and you
want to do a facade of the front of the
church we've got the main body and then
you have a bell tower at the top and
next to the bell tower you've got some
region which is not the facade of the
building which would want to
remove from your orthofacade. How would you do
this?
well first you have to make sure that
step 1 and step 2 have been
processed and then you would select an
image where you can see this background
that you want to remove from your orthofacade
then you can use the annotation tool
with the mask option and you can mark
the background in this image. You can do
this with several images to make sure
that all the background that you want to remove
has been annotated and then you can
generate the orthofacade to
get it without this background that you
want removed. Let's see in the software
step-by-step how to get this output and
how to use the annotation tool
here i am in in the project
this is the densified point cloud so
I'm going to start by inserting an orthoplane
object i just drop it and it
randomly in my project because what i
like to do is I like to align it to the
surface so i'm going to draw a new
surface object i'm going to draw it on
the side of the building that I want to
capture for this one here draw my surface
Great...
and now I can go back to the orthoplane and align it to the
surface and you see now it's in the
wrong direction so i can just flip it
there you go and now I can
can move it around a little bit
there we go...
now my orthoplane is on my facade and I
would be able to generate ...
the orthomosaic for the side of the building
Let me show you now how to
use the Annotate Tool so let me say that
in this region here i would like to
remove it from the orthofacade
so i'm going to click here and now
it's going to show all the images that
point to this feature. Going to zoom out
... a little bit and find an image that
works well where I can see the side of
the building quite well let's see: this one
and you can see here i can see this
region that I want to remove so i'm
going to use annotate it needs to
segment it, once it's ready
I can start clicking on the region that
I want to remove so you see i have to click
several times because what the software
does is that it breaks up the image into
sub regions and I have to select the
sub-region that I want to annotate out
of my orthofacade.
So like this requires a little bit of care
and here... So now i'm satisfied, i'm going to
mask it, click apply ...
...And now I can go back to my orthoplane here and I adjust
the side so that i can see this part
this and now I'm ready to go
I can generate the orthomosaic
and now it's running
I want to give you a few more tips to
make sure that you get good results with
this tool the first and maybe most
important thing to consider is that you
want to have good imagery of the side of
the building that you want to capture.
For example, if you only have nadir
images then the side of the building is
not going to appear in many images and
so there won't be many points generated.
If you want to capture this side of the
building and you know that you will want
to produce an orthofacade, we really
recommend to take some oblique imagery
and to make sure that you've got good
overlap and many images of the side of
the building and not just from above.
In your project you can check this by
looking at the side of the building and
making sure that you have enough points
and that you have enough images pointing
towards the side of the building.
We already mentioned that the green arrow
should be pointing towards the side of
the building that you want to capture
but it's also important for the orthoplane
to be parallel to the side of the
building. And finally to remove
background, we remind you that there's this
annotation tool that you've seen in the
software just previously.
That's all I wanted to say about orthofacades and
their generation i hope you found this
helpful and i'll see you in the next video!
For more infomation >> VIDEO - Duration: 4:52. 
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