Saturn's shadow

[Guest]

The saturn shadow cast on the rings doesn't look right, it should be much longer. Is there a way to make the shadow longer?

[granthutchison]

The shadow is correct. It's summer in Saturn's southern hemisphere at the moment, so the planet is tilted quite steeply away from the Sun, and sunlight can get past the southern hemisphere of Saturn to illuminate the outer edge of the rings.
Try going to the Sun, then tracking Saturn and zooming in on it - from the Sun, you'll be able see the far edge of the rings beyond Saturn's southern hemisphere. This shows you that sunlight is able to get to that part of the rings.

Grant

[JackHiggins]

Speaking of ring shadows... Is it possible to make the shadow of a planet onto it's rings smoother, and less "blocky" around the edges...? Saturn's shadow looks very pixelated around the edges to me...

[Guest]

Yep, granthutchison is right. I forgotten about the ring tilts. In the back of my mind I must've thought Celestia forgotten to include Saturn's ring tilts during its seasons.

[Kendrix]

Speaking of ring shadows... Is it possible to make the shadow of a planet onto it's rings smoother, and less "blocky" around the edges...? Saturn's shadow looks very pixelated around the edges to me...

Yes it's possible. In the "Renderer::init()" function change the :
shadowTex = CreateProceduralTexture(256, 256, ...

with

shadowTex = CreateProceduralTexture(1024, 1024, ...

Then all eclipse and ring shadow textures will be 16 times more precise !

I've never try beyond 1024 but it should work (depending on your graphic card of course).

[JackHiggins]

Kendrix,

Er.. Don't have a compiler, so can't actually change the code myself... I don't suppose you'd send me on an exe with that change made, would you?!!

Thanks!

[Kendrix]

Kendrix,

Er.. Don't have a compiler, so can't actually change the code myself... :( I don't suppose you'd send me on an exe with that change made, would you?!! :)

Thanks!

It's allright I can send you my version but I have made some other modifications...

CTRL + C switch the distance unit for all displays instead of copy the URL, you have a new option in the view menu : Choose constellation to render (to render only one constellation and see how it looks like from another star it's quite fun)
I have aded a progress bar in the eclipse finder dialog box.
My default FOV is 30 instead of 45 (you can easily change that with your starting script)
The rings are made of 1000 sections instead of 100...

I think that's all...

Do you still want my version ?

[JackHiggins]

Kendrix

That actually sounds better than what I was expecting!
a) I could never copy URL's before, so now Ctrl + C will actually do something for me
b) I like progress bars for things like the eclipse finder, when you have no idea how long it's going to take
c) I was going to ask about rings having 1000 sections also, but thought it might sound a bit pushy...!

Send it on so (zip it if you can too please) thanks!

[Kendrix]

Ok The exe is in your mailbox now

[JackHiggins]

Ok that looks SOOO much better than the standard version!!

I was actually more impressed by the 1000 section rings than I was by the better shadows (although they look great too) they stay completely round even when you're inside a ring following Pan around, etc.

The Ctrl + C feature is another great thing that I had never thought of before! One small feature request though- if you could get it to display radii as well, it'd have all the things that the "Go to" box has, as well as LT delay.

These features should definitely be in 1.3.2pre's!

[jim]

Kendrix or Jack,

can somewhere upload this 'exe' on the web or send a mail? This mods sound to good I must have it.

Thanks
Jens

[Kendrix]

Kendrix or Jack,

can somewhere upload this 'exe' on the web or send a mail? This mods sound to good I must have it. :D

Thanks
Jens

It's ok I've send it to you...

[JackHiggins]

I've also uploaded it to http://homepage.eircom.net/~jackcelesti ... lestia.zip for anyone else who wants it.

[Brendan]

Thank you for the new exe. Before, I could only see Saturn's shadow on the rings. Now I can also see the shadows of the rings on the planet. My card is:

Code: Select all

Vendor: ATI Technologies Inc.

Renderer: Radeon 7000 DDR x86/MMX/3DNow!/SSE

Version: 1.3.3036 WinXP Release

Max simultaneous textures: 3

Max texture size: 2048



Supported Extensions:

GL_ARB_multitexture

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_crossbar

GL_ARB_texture_env_dot3

GL_ARB_transpose_matrix

GL_ARB_vertex_blend

GL_ARB_window_pos

GL_S3_s3tc

GL_ATI_envmap_bumpmap

GL_ATI_texture_mirror_once

GL_ATI_vertex_streams

GL_ATIX_texture_env_combine3

GL_ATIX_texture_env_route

GL_ATIX_vertex_shader_output_point_size

GL_EXT_abgr

GL_EXT_bgra

GL_EXT_clip_volume_hint

GL_EXT_compiled_vertex_array

GL_EXT_draw_range_elements

GL_EXT_fog_coord

GL_EXT_packed_pixels

GL_EXT_point_parameters

GL_EXT_rescale_normal

GL_EXT_secondary_color

GL_EXT_separate_specular_color

GL_EXT_stencil_wrap

GL_EXT_texgen_reflection

GL_EXT_texture_env_add

GL_EXT_texture3D

GL_EXT_texture_compression_s3tc

GL_EXT_texture_cube_map

GL_EXT_texture_edge_clamp

GL_EXT_texture_env_combine

GL_EXT_texture_env_dot3

GL_EXT_texture_lod_bias

GL_EXT_texture_filter_anisotropic

GL_EXT_texture_object

GL_EXT_vertex_array

GL_KTX_buffer_region

GL_NV_texgen_reflection

GL_NV_blend_square

GL_SGI_texture_edge_clamp

GL_SGIS_texture_border_clamp

GL_SGIS_texture_lod

GL_SGIS_generate_mipmap

GL_SGIS_multitexture

GL_WIN_swap_hint

WGL_EXT_extensions_string

WGL_EXT_swap_control



But it is slow on my system with a 1.1 GHz AMD Athlon, 256mb memory, using 64 for the video and with WinXP. It would be nice if the numbers for the rings and shadows could be set in a place like celestia.cfg so we could experiment with what works best on our systems.

Brendan

[Kendrix]

The ring shadows you're seeing are not the pixel shader one.

It is a code replacement that Chris have done but deactivated since it doesn't draw the exact real thing.

I've activated it for a friend of mine...

[JackHiggins]

Funny- I couldn't get any ring shadows like Brendan... Must get a better graphics card...

[TERRIER]

Cheers for making the 'exe' available Kendrix, and to Jack for making it available on his site.
I'm mad on Saturn at the moment, and I've gotta take a look at this!

[Brendan]

Funny- I couldn't get any ring shadows like Brendan... Must get a better graphics card...

Ok, time to tense you. Here's what I see:

I can see them changing throughout the Saturn year. They look extreme because of how Saturn is tilted with respect to the sun now. Can someone post a picture of the pixel shader rings?
The picture is posted at http://www.rit.edu/~bjr5096/celestia/saturn.html

Brendan

[Kendrix]

Can someone post a picture of the pixel shader rings?
The picture is posted at http://www.rit.edu/~bjr5096/celestia/saturn.html

Brendan

I've send you a screenshot with Pixel Shaders so you can post it.

[Brendan]

Can someone post a picture of the pixel shader rings?
The picture is posted at http://www.rit.edu/~bjr5096/celestia/saturn.html

Brendan

I've send you a screenshot with Pixel Shaders so you can post it.

Thank you. I have posted the picture you sent me. The pixel shader shadows look better.

Brendan