[vtkusers] Noise appears when extreme zooming in
Patricio Palma C.
patriciop at gmail.com
Tue Oct 18 13:24:04 EDT 2016
Hi Ken, experts
I have double checked and the case shown in previous email, do not have
coincident geometries.
Regarding the interactor, I'm using a custom interactor style (derived from
vtkInteractorStyle) that provides a rubber band zoom into the 3D scene. The
code shows Dolly() function in custom interactor is calling camera->Zoom().
Regards
Patricio
On Tue, Oct 18, 2016 at 9:49 AM, Ken Martin <ken.martin at kitware.com> wrote:
> Are you zooming using one of VTK's interactor styles? or are you
> explicitly calling zoom or dolly on the camera? Using dolly() the distance
> on the camera should be changing and as you noticed it isn't.
>
> Since you mentioned you have coincident geometry that can be an issue.
> When you have two polygons at the same location the rendering process can
> result in a random determination of which is on top. If the coincident
> geometry is in two different mappers you can use the
>
> void SetRelativeCoincidentTopologyPolygonOffsetParameters(
> double factor, double units);
>
> method to move one of the mappers slightly in front of the other.
>
>
>
>
>
> On Tue, Oct 18, 2016 at 1:01 AM, Patricio Palma C. <patriciop at gmail.com>
> wrote:
>
>> Hi Ken, experts,
>>
>> Thank you for the quick response.
>> Regarding point one, SetDiffuse(0.0) was applied to all actors, the
>> structure looks darker with no shadows, but the issue still occurs.
>>
>> About point 2:
>> - the actor we use is derived from vtkQuadricLODActor
>> - and there are some overlapping geometries
>>
>> Below is a image of the structure in the beginning. Clipping range,
>> position, focal point and distance are shown below
>> [image: Inline image 1]
>> Debug: Camera clipping range: 3.61282 4.44839
>> Debug: Camera position: -1.93487 2.37646 2.48559
>> Debug: Camera focal point: 0.0543755 -0.0598546 0.0492757
>> Debug: Camera distance: 3.97849
>> Debug: Bounds : [ -0.100974 , 0.296875 , -0.08 ] [ 0.08 , 0 ,
>> 0.05 ]
>>
>> After zooming in a bit, it appears a soft pattern of lines over the face
>> of the structure
>> [image: Inline image 2]
>> Debug: Camera clipping range: 3.61282 4.44839
>> Debug: Camera position: -1.92875 2.37186 2.4952
>> Debug: Camera focal point: 0.0604954 -0.0644594 0.0588774
>> Debug: Camera distance: 3.97849
>> Debug: Bounds : [ -0.100974 , 0.296875 , -0.08 ] [ 0.08 , 0 ,
>> 0.05 ]
>>
>> Finally after zooming in a couple of steps more, it appears noise/lines
>> over the face.
>> [image: Inline image 3]
>> Debug: Camera clipping range: 3.61282 4.44839
>> Debug: Camera position: -1.92882 2.37202 2.49498
>> Debug: Camera focal point: 0.0604254 -0.0643013 0.0586621
>> Debug: Camera distance: 3.97849
>> Debug: Bounds : [ -0.100974 , 0.296875 , -0.08 ] [ 0.08 , 0 ,
>> 0.05 ]
>>
>> It calls my attention that only position and focal point are being
>> updated after zooming in.
>>
>> Thanks
>> Patricio
>>
>> On Mon, Oct 17, 2016 at 8:21 PM, Ken Martin <ken.martin at kitware.com>
>> wrote:
>>
>>> It could be a few things, we would really need more details to narrow it
>>> down. Two things you can check
>>>
>>> 1) maybe a lighting issue, if you change your actors to be only ambient,
>>> no diffuse, do you still see the issue?
>>>
>>> 2) maybe a zbuffer issue, If you zoom too far you can end up with bad
>>> (not ideal) zbuffer clipping ranges. To narrow that down
>>> - are these Actors or Actor2D, what mapper are you using,
>>>
>>> do you have overlapping or coincident geometry?
>>> - when you see the problem what is the value of
>>>
>>> - the camera's clipping range
>>> - camera's position, and focal point, distance
>>> - the bounds of your data
>>>
>>> Generally you do not want any of those values to be really small or
>>> large relative to the square root of the range a float can normally hold.
>>>
>>>
>>>
>>>
>>>
>>> On Mon, Oct 17, 2016 at 5:28 PM, Patricio Palma C. <patriciop at gmail.com>
>>> wrote:
>>>
>>>> Hi experts, does anybody has any idea of what could causing the issue
>>>> described in the previous email?
>>>> Recently I have noted that something similar occurs on 3D
>>>> structures when zooming in extremely to the structure and then rotating it.
>>>> It appears a kind of pattern to generate the shadow of the face but as you
>>>> rotate the structure the face begin to get noisy.
>>>>
>>>> My current setup is VTK git development branch using OpenGL2 as
>>>> rendering backend. mesa 12.0.1 with AVX. I have also tried using mesa 11.2
>>>> and the results are the same.
>>>>
>>>> Thanks!
>>>> Regards
>>>> Patricio
>>>>
>>>> El Monday, October 3, 2016, Patricio Palma C. <patriciop at gmail.com>
>>>> escribió:
>>>>
>>>>> Dear Experts
>>>>>
>>>>> I'm using VTK 7.1 (latest Git version) and Mesa 12.0 with AVX. I have
>>>>> an application that display a 2D structure and some data on it. After
>>>>> zooming in a couple times in the same spot of the structure it begins to
>>>>> appear some noise over the 2D structure that increase after continuing
>>>>> zooming in.
>>>>>
>>>>> Is this a known issue? is there a way to solve/avoid this?
>>>>>
>>>>> I've attached some pictures showing how the noise appears while
>>>>> zooming in.
>>>>>
>>>>> [image: Inline image 2]
>>>>> [image: Inline image 3]
>>>>> [image: Inline image 5]
>>>>> [image: Inline image 6]
>>>>>
>>>>> --
>>>>> Patricio Palma Contreras
>>>>>
>>>>
>>>>
>>>> --
>>>> Patricio Palma Contreras
>>>>
>>>>
>>>> _______________________________________________
>>>> Powered by www.kitware.com
>>>>
>>>> Visit other Kitware open-source projects at
>>>> http://www.kitware.com/opensource/opensource.html
>>>>
>>>> Please keep messages on-topic and check the VTK FAQ at:
>>>> http://www.vtk.org/Wiki/VTK_FAQ
>>>>
>>>> Search the list archives at: http://markmail.org/search/?q=vtkusers
>>>>
>>>> Follow this link to subscribe/unsubscribe:
>>>> http://public.kitware.com/mailman/listinfo/vtkusers
>>>>
>>>>
>>>
>>>
>>> --
>>> Ken Martin PhD
>>> Chairman & CFO
>>> Kitware Inc.
>>> 28 Corporate Drive
>>> Clifton Park NY 12065
>>> 518 371 3971
>>>
>>> This communication, including all attachments, contains confidential and
>>> legally privileged information, and it is intended only for the use of the
>>> addressee. Access to this email by anyone else is unauthorized. If you are
>>> not the intended recipient, any disclosure, copying, distribution or any
>>> action taken in reliance on it is prohibited and may be unlawful. If you
>>> received this communication in error please notify us immediately and
>>> destroy the original message. Thank you.
>>>
>>
>>
>>
>> --
>> Patricio Palma Contreras
>>
>
>
>
> --
> Ken Martin PhD
> Chairman & CFO
> Kitware Inc.
> 28 Corporate Drive
> Clifton Park NY 12065
> 518 371 3971
>
> This communication, including all attachments, contains confidential and
> legally privileged information, and it is intended only for the use of the
> addressee. Access to this email by anyone else is unauthorized. If you are
> not the intended recipient, any disclosure, copying, distribution or any
> action taken in reliance on it is prohibited and may be unlawful. If you
> received this communication in error please notify us immediately and
> destroy the original message. Thank you.
>
--
Patricio Palma Contreras
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://public.kitware.com/pipermail/vtkusers/attachments/20161018/42dbbd59/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: step0.jpg
Type: image/jpeg
Size: 3073 bytes
Desc: not available
URL: <http://public.kitware.com/pipermail/vtkusers/attachments/20161018/42dbbd59/attachment-0007.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: zoom2.jpg
Type: image/jpeg
Size: 46634 bytes
Desc: not available
URL: <http://public.kitware.com/pipermail/vtkusers/attachments/20161018/42dbbd59/attachment-0008.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: step1.jpg
Type: image/jpeg
Size: 2217 bytes
Desc: not available
URL: <http://public.kitware.com/pipermail/vtkusers/attachments/20161018/42dbbd59/attachment-0009.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: zoom1.jpg
Type: image/jpeg
Size: 37655 bytes
Desc: not available
URL: <http://public.kitware.com/pipermail/vtkusers/attachments/20161018/42dbbd59/attachment-0010.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: step2.jpg
Type: image/jpeg
Size: 5141 bytes
Desc: not available
URL: <http://public.kitware.com/pipermail/vtkusers/attachments/20161018/42dbbd59/attachment-0011.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: step3.jpg
Type: image/jpeg
Size: 8251 bytes
Desc: not available
URL: <http://public.kitware.com/pipermail/vtkusers/attachments/20161018/42dbbd59/attachment-0012.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: zoom3.jpg
Type: image/jpeg
Size: 66880 bytes
Desc: not available
URL: <http://public.kitware.com/pipermail/vtkusers/attachments/20161018/42dbbd59/attachment-0013.jpg>
More information about the vtkusers
mailing list