[GRASS-dev] v.in.lidar return filter

[Anna Petrášová]

On Tue, Sep 23, 2014 at 8:19 AM, Newcomb, Doug <doug_newcomb at fws.gov> wrote:

> It looks like the same patch needs to be applied to r.in.lidar main.c
> before line 791. So modifying to the following for both v.in.lidar and
> r.in.lidar  main.c should fix both?
>
> if (n_returns == 1) {
>
> switch (return_filter) {
> case LAS_FIRST:
>     if (return_no == 1)
> skipme = 0;
>     break;
>               }
> if (n_returns > 1) {
>
> switch (return_filter) {
> case LAS_FIRST:
>     if (return_no == 1)
> skipme = 0;
>     break;
> case LAS_LAST:
>     if (return_no == n_returns)
> skipme = 0;
>     break;
> case LAS_MID:
>     if (return_no > 1 && return_no < n_returns)
> skipme = 0;
>     break;
> }
>
>
Thanks, I rewrote it but it should be hopefully the same logic:

	    switch (return_filter) {

	    case LAS_FIRST:

		if (return_no == 1)

		    skipme = 0;

		break;

	    case LAS_MID:

		if (return_no > 1 && return_no < n_returns)

		    skipme = 0;

		break;

	    case LAS_LAST:

		if (n_returns > 1 && return_no == n_returns)

		    skipme = 0;

		break;


Committed in r62055 and backported.


Anna


 }

> Doug
>
>
> On Tue, Sep 23, 2014 at 8:05 AM, Newcomb, Doug <doug_newcomb at fws.gov>
> wrote:
>
>> I don't think it was intentional to drop first and only returns, but if
>> it is the first and only return the filter for First and Last Return would
>> both match.
>> Putting another if statement in front along the lines of  if(n_returns ==
>> 1) set case LAS_FIRST should fix it.
>>
>> Doug
>>
>>
>> On Mon, Sep 22, 2014 at 6:54 PM, Anna Petrášová <kratochanna at gmail.com>
>> wrote:
>>
>>> Hi,
>>>
>>> I want to import first return points with v.in.lidar, but I get only
>>> points where the pulse had more then one return. So it gives me trees but
>>> not ground or buildings. I looked in the code and there is an 'if' which
>>> skips points with only 1 return:
>>>
>>> http://trac.osgeo.org/grass/browser/grass/trunk/vector/v.in.lidar/main.c#L672
>>>
>>> So the behavior looks intentional but what's the reason?
>>>
>>> Thanks,
>>>
>>> Anna
>>>
>>> _______________________________________________
>>> grass-dev mailing list
>>> grass-dev at lists.osgeo.org
>>> http://lists.osgeo.org/mailman/listinfo/grass-dev
>>>
>>
>>
>>
>> --
>> Doug Newcomb
>> USFWS
>> Raleigh, NC
>> 919-856-4520 ext. 14 doug_newcomb at fws.gov
>>
>> ---------------------------------------------------------------------------------------------------------
>> The opinions I express are my own and are not representative of the
>> official policy of the U.S.Fish and Wildlife Service or Dept. of the
>> Interior.   Life is too short for undocumented, proprietary data formats.
>>
>
>
>
> --
> Doug Newcomb
> USFWS
> Raleigh, NC
> 919-856-4520 ext. 14 doug_newcomb at fws.gov
>
> ---------------------------------------------------------------------------------------------------------
> The opinions I express are my own and are not representative of the
> official policy of the U.S.Fish and Wildlife Service or Dept. of the
> Interior.   Life is too short for undocumented, proprietary data formats.
>
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