Dark areas in paraview
2 Attachment(s)
Hi everyone,
I'm getting some strange dark patches when I view cases in paraview (see the attached images). From the front the patches appear dark, but from the back they are light. The patches do not seem to affect the cases as they run fine and checkMesh says the mesh is ok, so this seems to be more of an aesthetic problem! I've played around with the lighting in paraview and it appears as if the face normals are inverted, ie changing the backlight affects the dark patches on the front, while they are unaffected by chances to the front lighting. Does anyone know how this could have happened? I'm using snappyHexMesh to mesh the blades of the turbine, could it be something to do with this? If so it seems strange that the mesh passes checkMesh and solves fine. If anyone has any ideas it would be greatly appreciated! Alistair |
Greetings Alistair,
Mmm, this is interesting... OK, two possibilities come to mind:
Best regards, Bruno |
2 Attachment(s)
Hi Bruno,
Thanks for getting back to me, I'll answer all of the questions I can, the computer was set up and OpenFoam software installed by my supervisor so I'm not too familiar with the internal workings, he's away today and tomorrow so I won't be able to get any answers on that front for a little while unfortunately. The blue patches are indeed from an stl file, the case is 3D, the screenshots are just from a slice. I've attached two more screenshots from a case using the same stl file, but with better refinement, hopefully the screenshot of the wireframe will make it clearer what the mesh looks like. The edges of the blue patches are the boundaries of the mesh. As you can see in the more refined mesh the areas move and become smaller with the mesh, I've also played with the lighting in paraview so they appear less pronounced, but I still can't completely get rid of them. The files open in paraview with the extension .OpenFOAM and desktop animations are turned on. Is there anything I can do to test whether the drivers for the graphics card are installed properly? I haven't seen anything else that suggests they aren't, videos etc seem to play fine. Regards, Alistair |
|
I know this is an old thread but I'm posting for anyone who has had similar problems as I have......
If the problem is in fact due to the surface normals, there is a filter within paraview (GenerateSurfaceNormals) which allows you to flip them and which (for me at least) has solved the lighting problems! Hope that helps someone! plm |
Greetings to all!
I'm bumping up this thread to add some more information on this topic, which I discovered this week. When using an Intel HD GPU (one of those integrated with the CPU), there are some somewhat known issues with the OpenGL drivers, allegedly due to Intel not implementing a more recent version of OpenGL. Anyway, an example with a pretty extensive attempt at fixing a similar issue of "black triangles" on Windows: 'Black Triangles' in Tomb Raider II (Win7-64) Either way, plm's fixed partially the problem I had as well with said Intel HD GPU (on Windows!), namely by applying the "Generate Surface Normals" filter. Beyond this (and the reason for this post), I found the following details:
Bruno PS: For those confused by me mentioning VTK, this is because ParaView uses VTK. |
how can I correct this in paraview
1 Attachment(s)
Hi, just wondering if any of you know why paraview displays my solution with some patches like in the attached pic?...
Thanks |
Looks like multiple representations on top of each other. Blank all but one, and see if things change.
|
Quote:
When I run the script you mentioned I get following error: AttributeError: type object "RenderView" has not attribute "LightSwitch". I am using Paraview 5.6.0 (64 bit). When I comment this line it works. Is there a way to also execute the first line of the code which gives the error? Many thanks for your help! |
All times are GMT -4. The time now is 04:48. |