 |
This chapter lists a few tips to align a cloud
with another cloud, or a cloud with surfaces. |
|
These recommendations apply to clouds or to a cloud and
surfaces that have similar shapes,
where the cloud to align will cover the reference cloud or the reference
surfaces. |
|
-
Do not modify the reference (cloud or surfaces).
-
To reduce the computation time, filter the cloud to align.
Use the homogeneous filtering (the
repartition of points is more suitable),
and choose a filtering value that leaves only a few thousand points.
-
You can either:
-
Select the whole cloud to align, and the whole reference
(cloud or surfaces).
-
or portions of the cloud and only some surfaces of a
model.
In this case, be careful that the selected areas/surfaces have similar
shapes.
This first step may take a few minutes. |
 |
-
Check whether the cloud has been aligned correctly.
-
Depending on what you see:
-
If the result is not correct,
-
Undo the alignment and start again.
-
This time, try to select a characteristic portion
of the cloud to align, and its counterpart on the reference:
for instance, if the shape is symmetrical, select a portion that
is not.
-
If the result is correct,
-
Hide the cloud to align and unfilter the output
cloud.
-
Select the whole output cloud and the reference,
-
Repeat this step if necessary.
-
If the cloud to align is large, you can filter it,
but keep more points than for the first step.
-
Now, the result seems correct:
- Use the
Deviation Analysis for the last controls.
- The first set is the cloud to align, the second set is the
reference cloud or the surfaces.
- Set the Discretization at 100, uncheck Min/Max Values,
Points and Spikes.
- Use the Limited color range with the values you
require.
- Faulty areas will appear in red, correct areas in green.
|
-
To remove faulty areas:
- Select the areas in red, and some areas in green, and launch
another computation.
- The areas in green will act as a fastener, while the areas in
red will be improved.
|
|
|
Altogether, aligning a cloud with another cloud or
surface should require 3 or 4 iterations.
If the result is not yet satisfactory after 4 iterations, you probably will
not be able to improve it. |
 |