Hi Jean, Thanks for the list of extensions that you test for in the ShadowMap. However, I have a graphics card that meets those requirements yet still does not render ShadowMap shadows. Can you tell me if any of these extensions look like the 'smoking gun' as to why this card does not display shadows?
Here is a list of extensions that ARE NOT supported on this graphics card. This list was extracted from a diff between a working graphics card that does display shadows and the current 'broken' one. I am sure there are more extensions that are not listed here that I am unaware of. GL_ARB_draw_buffers GL_ARB_fragment_shader GL_ARB_multisample GL_ARB_shader_objects GL_ARB_shading_language_100 GL_ARB_transpose_matrix GL_ARB_vertex_buffer_object GL_ARB_vertex_shader GL_ATI_draw_buffers GL_EXT_blend_equation_separate GL_EXT_compiled_vertex_array GL_EXT_Cg_shader GL_EXT_depth_bounds_test GL_EXT_framebuffer_blit GL_EXT_framebuffer_multisample GL_EXT_gpu_program_parameters GL_EXT_point_parameters GL_EXT_stencil_two_side GL_NV_fence GL_NV_fragment_program GL_NV_framebuffer_multisample_coverage GL_NV_half_float GL_NV_occlusion_query GL_NV_pixel_data_range GL_NV_point_sprite GL_NV_primitive_restart GL_NV_register_combiners GL_NV_register_combiners2 GL_NV_vertex_array_range GL_NV_vertex_array_range2 GL_NV_vertex_program GL_NV_vertex_program1_1 GL_NV_vertex_program2 GL_NVX_conditional_render This is the list of extensions are ARE supported by this 'broken' card that does not display shadows: GL_ARB_color_buffer_float GL_ARB_depth_texture GL_ARB_fragment_program GL_ARB_fragment_program_shadow GL_ARB_half_float_pixel GL_ARB_imaging GL_ARB_multitexture GL_ARB_occlusion_query GL_ARB_pixel_buffer_object GL_ARB_point_parameters GL_ARB_point_sprite 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_float GL_ARB_texture_mirrored_repeat GL_ARB_texture_non_power_of_two GL_ARB_texture_rectangle GL_ARB_vertex_program GL_ARB_window_pos GL_ATI_texture_float GL_ATI_texture_mirror_once GL_S3_s3tc GL_EXT_texture_env_add GL_EXT_abgr GL_EXT_bgra GL_EXT_blend_color GL_EXT_blend_func_separate GL_EXT_blend_minmax GL_EXT_blend_subtract GL_EXT_draw_range_elements GL_EXT_fog_coord GL_EXT_framebuffer_object GL_EXT_multi_draw_arrays GL_EXT_packed_depth_stencil GL_EXT_packed_pixels GL_EXT_pixel_buffer_object GL_EXT_rescale_normal GL_EXT_secondary_color GL_EXT_separate_specular_color GL_EXT_shadow_funcs 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_combine GL_EXT_texture_env_dot3 GL_EXT_texture_filter_anisotropic GL_EXT_texture_lod GL_EXT_texture_lod_bias GL_EXT_texture_mirror_clamp GL_EXT_texture_object GL_EXT_texture_sRGB GL_EXT_timer_query GL_EXT_vertex_array 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_float_buffer GL_NV_fog_distance GL_NV_fragment_program_option GL_NV_fragment_program2 GL_NV_light_max_exponent GL_NV_multisample_filter_hint GL_NV_packed_depth_stencil GL_NV_texgen_reflection GL_NV_texture_compression_vtc GL_NV_texture_env_combine4 GL_NV_texture_expand_normal GL_NV_texture_rectangle GL_NV_texture_shader GL_NV_texture_shader2 GL_NV_texture_shader3 GL_NV_vertex_program2_option GL_NV_vertex_program3 GL_SGIS_generate_mipmap GL_SGIS_texture_lod GL_SGIX_depth_texture GL_SGIX_shadow GL_SUN_slice_accum Thanks, -Ben -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jean-Sébastien Guay Sent: Monday, September 22, 2008 8:12 PM To: OpenSceneGraph Users Subject: Re: [osg-users] openGL extensions Hi Ben, > I would like to detect if the user has the appropriate openGL extensions > in order to do shadowing. However, when I do: > > glGetString(GL_VERSION) > glGetString(GL_EXTENSIONS) > > They return null. How can I get a list of the available extensions? Is > there an easy way to get this info from OSG? For the first part of your question, they return NULL if they were called from a thread that does not have a graphics context. The safest way to do this is to create a camera predraw/postdraw/finaldraw callback or a node cull callback or a drawable draw callback. In each of these points you will have a graphics context. What I generally do is assume support is present and start the viewer with a detection callback attached (camera predraw callback on the main camera) which will check extensions and then remove itself from the camera. Then after the first frame, if I see that some feature is not supported, I disable the relevant options. There are other valid strategies of course. As for detecting actual extensions, instead of calling glGetString(GL_EXTENSIONS) and parsing it yourself, you can use #include <osg/GLExtensions> #include <osg/GL2Extensions> osg::isGLExtensionSupported(contextID, extensionName) > Also, how do I know which extensions I need for the different shadow > techniques? I'm personally not sure which extensions are required for all of them, perhaps someone else will know (it might be good to add that info to the osgShadow page on the wiki). I can tell you what I test for in the case of osgShadow::ShadowMap: _shadowsSupported = osg::isGLExtensionSupported(contextID, "GL_EXT_framebuffer_object") && (osg::isGLExtensionSupported(contextID, "GL_ARB_fragment_program") || osg::isGLExtensionSupported(contextID, "GL_EXT_fragment_program")) && (osg::isGLExtensionSupported(contextID, "GL_ARB_fragment_program_shadow") || osg::isGLExtensionSupported(contextID, "GL_EXT_fragment_program_shadow")); Not sure if that's totally correct, but in most cases where shadow maps were not supported (they fell back to software and so were extremely slow) it was the first (GL_EXT_framebuffer_object) which was not supported. Hope this helps, J-S -- ______________________________________________________ Jean-Sebastien [EMAIL PROTECTED] http://www.cm-labs.com/ http://whitestar02.webhop.org/ _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
