[Imstk-developers] Clearing surface mesh data on intialization

[Alexis Girault]

Is `initialize` only used in the readers currently? I believe the goal of
that function was just to set vertices, triangles, or any other topology
information needed in a single function. It should only be used after the
constructor as a utility as far as I understand, so there shouldn't be data
already set in the mesh at that point.

When/where is this function currently called and creating an issue in your
case?

Also, I think the `clear `should only delete the derived data computed by
the initialization input. Is it doing more than that now which would
explain why it deletes your data?

I think having an `initialize` function that clears derived data fields and
set core parameters is good, we need to make sure it is called at a good
place and does not remove some unexpected fields (but I just think it
should be called before you try to set any data in it)

Alexis Girault
R&D Engineer in Medical Computing
Kitware, Inc.

http://www.kitware.com
(919) 969-6990 x325

On Thu, Jul 27, 2017 at 5:03 PM, Milef, Nicholas Boris <milefn at rpi.edu>
wrote:

> For now, I can just put the seam computation before the clear. However,
> this will break if the vertex order changes or something like that.
> Basically, what I'm trying to say is that I would want users to know
> explicitly if they're messing up their data. A reinitialize function
> doesn't convey this imo.
> ------------------------------
> *From:* Imstk-developers [imstk-developers-bounces at imstk.org] on behalf
> of Milef, Nicholas Boris [milefn at rpi.edu]
> *Sent:* Thursday, July 27, 2017 4:47 PM
> *To:* Sreekanth Arikatla
>
> *Cc:* imstk-developers at imstk.org
> *Subject:* Re: [Imstk-developers] Clearing surface mesh data on
> intialization
>
> I guess where I'm stuck at is why we have an initialize function to begin
> with. I still can't think of a use-case where we can't either 1) make a new
> mesh or 2) modify the components of the old mesh.
> ------------------------------
> *From:* Sreekanth Arikatla [sreekanth.arikatla at kitware.com]
> *Sent:* Thursday, July 27, 2017 4:37 PM
> *To:* Milef, Nicholas Boris
> *Cc:* imstk-developers at imstk.org
> *Subject:* Re: [Imstk-developers] Clearing surface mesh data on
> intialization
>
> Hi Nick,
>             If you want to preserve the normals, you can add normals to
> the Initialize function arg. If the normals are supplied, initialize clears
> the previous data before assigning.
>
> On Thu, Jul 27, 2017 at 4:01 PM, Milef, Nicholas Boris <milefn at rpi.edu>
> wrote:
>
>> No, I don't. I need to preserve the original normals that ASSIMP imports
>> because ASSIMP calculates the normals correctly. Otherwise, I can't
>> identify the UV seams.
>>
>> I can just do this computation in the SurfaceMeshRenderDelegate, but I'm
>> not sure if the normals are used elsewhere after reinitializing the meshes.
>> But isn't reinitializing a mesh dangerous in a multithreaded environment
>> anyway?
>> ------------------------------
>> *From:* Sreekanth Arikatla [sreekanth.arikatla at kitware.com]
>> *Sent:* Thursday, July 27, 2017 3:55 PM
>>
>> *To:* Milef, Nicholas Boris
>> *Cc:* imstk-developers at imstk.org
>> *Subject:* Re: [Imstk-developers] Clearing surface mesh data on
>> intialization
>>
>> It could be used in some cases depending on the scenario. Do you plan to
>> call this at every frame?
>>
>>
>> On Thu, Jul 27, 2017 at 3:53 PM, Milef, Nicholas Boris <milefn at rpi.edu>
>> wrote:
>>
>>> Is that a useful use case though? Why not just make a new mesh?
>>> ------------------------------
>>> *From:* Sreekanth Arikatla [sreekanth.arikatla at kitware.com]
>>> *Sent:* Thursday, July 27, 2017 3:52 PM
>>> *To:* Milef, Nicholas Boris
>>> *Cc:* imstk-developers at imstk.org
>>> *Subject:* Re: [Imstk-developers] Clearing surface mesh data on
>>> intialization
>>>
>>> Hi Nick,
>>>             This is cleared in case one wants to reinitialize the mesh
>>> with a different data. Initialize should only be called at initilization or
>>> at runtime if the mesh data itself changes.
>>>
>>> On Thu, Jul 27, 2017 at 3:31 PM, Milef, Nicholas Boris <milefn at rpi.edu>
>>> wrote:
>>>
>>>> I'm modifying the SurfaceMesh class currently, but why is all the data
>>>> cleared on initialization? Is this necessary? I ask because I need this
>>>> data to correct for the normals seams.
>>>>
>>>> _______________________________________________
>>>> Imstk-developers mailing list
>>>> Imstk-developers at imstk.org
>>>> http://public.kitware.com/mailman/listinfo/imstk-developers
>>>>
>>>>
>>>
>>>
>>> --
>>> Sreekanth Arikatla, Ph.D.,
>>> Senior R&D Engineer,
>>> Kitware, Inc. <http://www.kitware.com>, Carrboro, NC.
>>>
>>>
>>
>>
>> --
>> Sreekanth Arikatla, Ph.D.,
>> Senior R&D Engineer,
>> Kitware, Inc. <http://www.kitware.com>, Carrboro, NC.
>>
>>
>
>
> --
> Sreekanth Arikatla, Ph.D.,
> Senior R&D Engineer,
> Kitware, Inc. <http://www.kitware.com>, Carrboro, NC.
>
>
> _______________________________________________
> Imstk-developers mailing list
> Imstk-developers at imstk.org
> http://public.kitware.com/mailman/listinfo/imstk-developers
>
>
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