Help! Screenshots are skewed!

[Celestia user in distress]

When taking a screenshot with Celestia, the first 640x480 portion (starting from top left) of the image seems to “Light up” for no apparent reason. The stars in the background are much brighter than they should be, and this anomaly is spread uniformly throughout what seems to be close to a 640x480 window, the screenshot looks normal outside of that boundary. In addition to this, if a planet with an atmosphere falls in this area, the atmosphere will become dark and unnatural looking.

In an effort to rule out my local software and hardware, I installed Celestia v. 1.3.0 on a remote machine and tested with the same results. I then obtained the latest versions of Direct X 9.0 and Windows Media Player on the original machine, and tested with the same results. I thought maybe the 1.3.1 pre 9 release would remedy this issue, but to no avail: same results. Maybe someone has experienced this same issue.

The primary machine as tested is running a 1GHz PIII with ~448 MB ram and an nVidia GeForce4 TI 4200 w/ 64 MB video ram. The remote machine is similar in hardware configuration, running a 1.4GHz P4 with 320 MB ram and an nVidia GeForceFX Ultra w/ 128 MB video ram.

I would like to be able to take realistic screenshots with Celestia, but do not have the time to figure out what is going on myself! Someone help! Thank you in advance for your considerate efforts.

- Celestia user in distress.

In an effort to be of more assistance I have included an example of a screenshot created by my system & Celestia. Please see the following image:

[selden]

Please read the 'preliminary User's FAQ' at the top of the Users Forum: http://63.224.48.65/forum/viewtopic.php?t=2291

Q8/A8
answers your question.

[Celestia user in distress]

This fix doesn't seem to work for me. I've tried Celestia v. 1.3.0 and 1.3.1 pre9 with the same results. Pressing "U" twice to disable and enable galaxy rendering, but produced identical results. I even tried disabling the rendering of everything except stars. But still produced the same results. I’m going to try and download Celestia v. 1.2.4. I know I’ve taken screenshots before with Celestia and not had this issue. I’m thinking it’s exclusive to the higher versions, but am not sure as of yet. Thanks again for your help!

[Celestia user in distress]

Ok. I tried 1.2.4 with the same results. Even pressing U twice as instructed in the faq did not resolve the issue. I ran a quick search of my hard drive and found several images that were taken with Celestia v. 1.2.4 around late November, 2002 in which this issue is not present. I have the most up-to-date graphics drivers for my video card. The next step (don’t know if this is right) is to remove all traces of installed Celestia from my system and reinstall 1.2.4, then test. If the issue persists, I’m thinking this is related to how Celestia works with the latest version of Microsoft Direct X 9.0. If, when I test Celestia after having removed the program completely from my system and the issue still exists, I’ll install 1.2.4 on a Windows XP machine that does not yet have direct X 9 installed, and see what happens from there…

Thanks again for you help.

[Celestia user in distress]

Ok. I was able to install 1.2.4 on a machine running DX v. 8.1 and take a successful, clean and correct snapshot.

Installed 1.3.1 pre9 and tested: was able to produce uniform image.

What do you think? I’m afraid to download the latest version of direct X on this machine, but I did download the latest video drivers and tested positively, the issue did not show up.

I apologize for being rather scant with the details. I’m very busy and do not have much time available.

[don]

As an outside possibility, have you tried resetting the card's OpenGL values to "default"?

-Don G.

[Celestia user in distress]

Yes. Same issue. Celestia seems to only capture images properly when ALL Direct3D and OpenGL acceleration settings are disabled.

[don]

Okay ...

Are your graphics card drivers current?

If yes, you might want to copy the info you get when using "Help / OpenGL Info" and paste it here for the developers to use.

Wish I could be or more help <sigh>.

-Don G.

[Celestia user in distress]

Yes, graphics drivers are current. Here is the info:

I hope you'll find the need for "All" the info. . .

Vendor: NVIDIA Corporation
Renderer: GeForce4 Ti 4200 with AGP8X/AGP/SSE
Version: 1.4.0
Max simultaneous textures: 4
Max texture size: 4096

Supported Extensions:
GL_ARB_depth_texture
GL_ARB_imaging
GL_ARB_multisample
GL_ARB_multitexture
GL_ARB_point_parameters
GL_ARB_shadow
GL_ARB_texture_border_clamp
GL_ARB_texture_compression
GL_ARB_texture_cube_map
GL_ARB_texture_env_add
GL_ARB_texture_env_combine
GL_ARB_texture_env_dot3
GL_ARB_texture_mirrored_repeat
GL_ARB_transpose_matrix
GL_ARB_vertex_buffer_object
GL_ARB_vertex_program
GL_ARB_window_pos
GL_S3_s3tc
GL_EXT_abgr
GL_EXT_bgra
GL_EXT_blend_color
GL_EXT_blend_minmax
GL_EXT_blend_subtract
GL_EXT_compiled_vertex_array
GL_EXT_draw_range_elements
GL_EXT_fog_coord
GL_EXT_multi_draw_arrays
GL_EXT_packed_pixels
GL_EXT_paletted_texture
GL_EXT_point_parameters
GL_EXT_rescale_normal
GL_EXT_secondary_color
GL_EXT_separate_specular_color
GL_EXT_shadow_funcs
GL_EXT_shared_texture_palette
GL_EXT_stencil_wrap
GL_EXT_texture3D
GL_EXT_texture_compression_s3tc
GL_EXT_texture_cube_map
GL_EXT_texture_edge_clamp
GL_EXT_texture_env_add
GL_EXT_texture_env_combine
GL_EXT_texture_env_dot3
GL_EXT_texture_filter_anisotropic
GL_EXT_texture_lod
GL_EXT_texture_lod_bias
GL_EXT_texture_object
GL_EXT_vertex_array
GL_HP_occlusion_test
GL_IBM_rasterpos_clip
GL_IBM_texture_mirrored_repeat
GL_KTX_buffer_region
GL_NV_blend_square
GL_NV_copy_depth_to_color
GL_NV_depth_clamp
GL_NV_fence
GL_NV_fog_distance
GL_NV_light_max_exponent
GL_NV_multisample_filter_hint
GL_NV_occlusion_query
GL_NV_packed_depth_stencil
GL_NV_pixel_data_range
GL_NV_point_sprite
GL_NV_register_combiners
GL_NV_register_combiners2
GL_NV_texgen_reflection
GL_NV_texture_compression_vtc
GL_NV_texture_env_combine4
GL_NV_texture_rectangle
GL_NV_texture_shader
GL_NV_texture_shader2
GL_NV_texture_shader3
GL_NV_vertex_array_range
GL_NV_vertex_array_range2
GL_NV_vertex_program
GL_NV_vertex_program1_1
GL_NVX_ycrcb
GL_SGIS_generate_mipmap
GL_SGIS_multitexture
GL_SGIS_texture_lod
GL_SGIX_depth_texture
GL_SGIX_shadow
GL_WIN_swap_hint
WGL_EXT_swap_control

[bh]

mmm...must be frustrating. I have no probs with screen capture (v 1.3.0). Maybe Chris should come in here.

bh.

[don]

Thanks for the OpenGL info Guest.

Hey Chris, are you out there?

What's next on the check-list here?

What does Celestia use to capture a screen shot? DirectX, OpenGL, Windows API, or???

Hope you can help.

-Don G.

[selden]

When it's happened to me, the bright areas are usually where the snapshot file-requestor or other wndows overlapped with Celestia's main window.

One way to work around the problem is not to run Windows full-screen. Then you can push the other windows out from in front of Celestia's window.

Also, most Ti4200 cards have both digital and analog video outputs. You might consider getting a very inexpensive CRT and using it as a second screen. (The digital connector includes an analog output. Adaptor cables or connectors are cheaply available if your card didn't come with one.) You can run Celestia full screen on the primary screen and push the menus onto the secondary screen.

FWIW, I'm not seeing this problem on my system:
256MB 500MHz P3, Windows XP Pro SP1
128MB GF4 Ti4200, Detonator 44.03 (Microsoft WHQL driver), OpenGL 1.4.0
Celestia 1.3.1pre9
Directx9.0a (4.09.0000.0901)

[Celestia user in distress]

When it's happened to me, the bright areas are usually where the snapshot file-requestor or other wndows overlapped with Celestia's main window.

One way to work around the problem is not to run Windows full-screen. Then you can push the other windows out from in front of Celestia's window.

Hey, wow! It works! Thanks for the workaround!
[/quote]

[selden]

You're quite welcome. I'll update the FAQ to include this.

[don]

Thanks for nailing this one Selden, and adding it to the FAQ!

[Relieved Celestia user]

Again, I still don't have the time to figure out the reason behind this issue, but I highly suspect this directly related to Celestia's handling of changes made with Microsoft's revamp of DirectX. (Probably not worded very well, but you know what point I'm trying to make, though (I hope)).