<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - [SKL] Improper rendering in Europa Universalis IV" href="https://bugs.freedesktop.org/show_bug.cgi?id=96958#c5">Comment # 5</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - [SKL] Improper rendering in Europa Universalis IV" href="https://bugs.freedesktop.org/show_bug.cgi?id=96958">bug 96958</a> from <a class="email" href="mailto:jakub+mesa@streamcomputing.eu" title="Jakub Szuppe <jakub+mesa@streamcomputing.eu>"> Jakub Szuppe</a> <pre>There are two different bugs/issues here: 1) Artefacts looking like stretched textures (for example, between mountains and plains) 2) Low detail of the terrain 1) Artefacts looking like stretched textures (for example, between mountains and plains): <a href="https://drive.google.com/open?id=0B1fY17pW39ZecW5DeWhnaGtrNHc">https://drive.google.com/open?id=0B1fY17pW39ZecW5DeWhnaGtrNHc</a> These artefacts are visible only when anisotropic filtering is turned on (for example, maxanisotropy=4 in ~/.local/share/Paradox Interactive/Europa Universalis IV/settings.txt). The reason is the same as in "95530 - Stellaris - colored overlay of sectors doesn't render on i965" (see <a class="bz_bug_link bz_status_REOPENED " title="REOPENED - Stellaris - colored overlay of sectors doesn't render on i965" href="show_bug.cgi?id=95530#c11">https://bugs.freedesktop.org/show_bug.cgi?id=95530#c11</a>): The shader needs exact (unfiltered) values from a special texture with terrain type ids. But i965 driver disables GL_NEAREST filtering (and enables anisotropic) when GL_TEXTURE_MAX_ANISOTROPY_EXT > 1. The patch <a href="https://bugs.freedesktop.org/attachment.cgi?id=123400">https://bugs.freedesktop.org/attachment.cgi?id=123400</a> fixes this: <a href="https://drive.google.com/open?id=0B1fY17pW39Zea1JfN09wa24xVEU">https://drive.google.com/open?id=0B1fY17pW39Zea1JfN09wa24xVEU</a> It also improves UI rendering slightly, because it uses GL_NEAREST too. 2) Low detail of the terrain First, we used a trace created using i965 driver (the "ugly" trace). This trace works same for i965, radeonsi, llvmpipe: low details, artefacts between tiles (vertical and horizontal lines). Then we used the trace created using radeonsi (the "good" trace) and noticed that it works same for i965, radeonsi, llvmpipe: high details, bump-mapping, no artefacts. Th only difference between "good" and "ugly" traces is in shaders code: The "ugly" has: #define NO_SHADER_TEXTURE_LOD (texture2D is used in this case) The "good" has: #extension GL_ARB_shader_texture_lod : enable (texture2DLod is used) For some reason the game does not enable texture_lod extension for Intel driver. But GL_ARB_shader_texture_lod is supported by the i965 driver! We "hacked" gfx/FX/defines_glsl.fxh by adding these code: #undef NO_SHADER_TEXTURE_LOD #extension GL_ARB_shader_texture_lod : enable This forces the shader to use the "good" variant. Everything looks ok (high details, bump-mapping, no artefacts): <a href="https://drive.google.com/open?id=0B1fY17pW39ZeRWJlbWlXbXpyZFU">https://drive.google.com/open?id=0B1fY17pW39ZeRWJlbWlXbXpyZFU</a> Perhaps the game developers encountered some issues with Intel drivers before or there are issues in some other places of the game (but I can't see them). Kind regards, Stream HPC Team <a href="https://streamhpc.com/">https://streamhpc.com/</a></pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>