[vtkusers] Problem with shadows

[David Gobbi]

Can you attach a screenshot?  My own experience with VTK tells me that it
is very, very unlikely that you are seeing shadows.  Whenever I see dark
areas in VTK rendering, it is almost always due to the scalars, the
normals, or the winding of the polydata.  It could be that some of your
polygons are wound incorrectly.

On Fri, Jul 21, 2017 at 12:37 PM, abcd efgh <adarshdesai.dsp at gmail.com>
wrote:

> previously forgot to add VTKusers list.. forwarding same mail.
>
> Hi,
>
> Thank you for the input. I have tried with new Normals, its the same.
> I dont think there is an issue with normals. When Poly data appears on
> screen, it will be in darkness(shadow).
> I need to turn off every shadow in the renderer. I am using
> Renderer->UseShadowsOff(), still no use.
>
> Please someone guide me to turn off all shadows in the scene. Just like
> how the Cube source appears in the renderer.
>
> Thanks
>
> On Thu, Jul 20, 2017 at 3:52 PM, abcd efgh <adarshdesai.dsp at gmail.com>
> wrote:
>
>> Hi,
>>
>> Thank you for the input. I have tried with new Normals, its the same.
>> I dont think there is an issue with normals. When Poly data appears on
>> screen, it will be in darkness(shadow).
>> I need to turn off every shadow in the renderer. I am using
>> Renderer->UseShadowsOff(), still no use.
>>
>> Please someone guide me to turn off all shadows in the scene. Just like
>> how the Cube source appears in the renderer.
>>
>> Thanks
>>
>> On Mon, Jul 17, 2017 at 12:06 PM, David Gobbi <david.gobbi at gmail.com>
>> wrote:
>>
>>> If it isn't the scalars, then it is probably the normals.  If the data
>>> has bad normals, then lighting of the data will be incorrect.
>>>
>>> You can try generating new normals for the data with
>>> vtkPolyDataNormals.  Make sure that you read the documentation for this
>>> class, it has lots of options.
>>>
>>>  - David
>>>
>>>
>>> On Mon, Jul 17, 2017 at 12:31 PM, abcd efgh <adarshdesai.dsp at gmail.com>
>>> wrote:
>>>
>>>> Thanks,
>>>> if  I turn off scalars then I see only white color, by the way even
>>>> after that I see the shadow effects, how can I turn off the shadows in the
>>>> scene completely.
>>>> I think the problem is with respect to shadows.
>>>>
>>>> Thanks again.
>>>>
>>>> On Sun, Jul 16, 2017 at 5:21 AM, David Gobbi <david.gobbi at gmail.com>
>>>> wrote:
>>>>
>>>>> Clipping a data set adds scalars to the data set. These scalars are
>>>>> probably causing the strange coloring that you are seeing. You can tell the
>>>>> mapper to ignore the scalars, and use the vtkProperty color instead:
>>>>>
>>>>> mapper->ScalarVisibilityOff();
>>>>>
>>>>>  - David
>>>>>
>>>>> On Sun, Jul 16, 2017 at 2:15 AM, abcd efgh <adarshdesai.dsp at gmail.com>
>>>>> wrote:
>>>>>
>>>>>> Hello,
>>>>>>
>>>>>> I am new to vtk. I have a 3D polydata, I cut it using vtkClipPolydata.
>>>>>> Now there are some shadow kind of thing, I have called functions to
>>>>>> turn off shadows
>>>>>> as well as backface culling as off. But still shadow kind of effect
>>>>>> remains and the Poly data is sometimes dark due to this.
>>>>>>
>>>>>> Thanks
>>>>>>
>>>>>
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