https://bugs.dolphin-emu.org/https://bugs.dolphin-emu.org/favicon.ico?12022-12-04T22:02:56ZDolphin bug trackerEmulator - Emulator Issues #13119: Kirby Air Ride texture behavior does not match original hardwarehttps://bugs.dolphin-emu.org/issues/13119?journal_id=7456472022-12-04T22:02:56Zpokechu22
<ul><li><strong>Description</strong> updated (<a title="View differences" href="/journals/745647/diff?detail_id=180631">diff</a>)</li></ul><p>Can you record 3 fifologs of the ice scene at <a href="https://youtu.be/ApgM9UN1FJA?t=20" class="external">https://youtu.be/ApgM9UN1FJA?t=20</a>, one looking towards the ice, one looking towards the wall, and one looking away from the ice, and then attach them to this report? (Use 7-zip if they're too big to attach directly.)</p>
Emulator - Emulator Issues #13119: Kirby Air Ride texture behavior does not match original hardwarehttps://bugs.dolphin-emu.org/issues/13119?journal_id=7456482022-12-05T00:19:09ZLandfill7377
<ul><li><strong>File</strong> <a href="/attachments/9357">kirby fifo logs.7z</a> <a class="icon-only icon-download" title="Download" href="/attachments/download/9357/kirby%20fifo%20logs.7z">kirby fifo logs.7z</a> added</li></ul><p>FIFO logs</p>
Emulator - Emulator Issues #13119: Kirby Air Ride texture behavior does not match original hardwarehttps://bugs.dolphin-emu.org/issues/13119?journal_id=7456492022-12-05T07:19:04Zpokechu22
<ul><li><strong>Status</strong> changed from <i>New</i> to <i>Accepted</i></li></ul><p>Thanks. I can confirm that those render differently on real hardware compared to dolphin. As far as I can tell, the game <em>isn't</em> trying to do anything special here, though. They render one section that's all ice, and then touching it is one section that's all ground. Then, later on in the frame, they render a partially transparent object over the ice section using the ground texture, where alpha (transparency) is set to 0 for vertices on the ice side and 1 for vertices on the ground side, which produces the fade between the two textures. (They could have used a single object that fades between the two textures separately, but I guess they already had everything set up for transparent objects and both methods work.)</p>
<p>However, there's something weird about how vertex colors get interpolated for triangles that go off screen. I'm not exactly sure how it works, but it seems like the colors get changed if the triangle is behind the camera (and perhaps also off the screen to the side). I was linked to an example of this happening on a homebrew game a long time ago, but I can't find that anymore; it was somewhat similar to the example on the roof though where you can see one of the the triangles changing colors. I also feel like I've seen something similar in Super Mario 64, though I'm not sure if that's related or not.</p>
<p>It would be neat to handle this case correctly since the effect actually looks quite nice in the tunnels (and it would be nice for accuracy in general). However, it probably won't be a high priority.</p>
Emulator - Emulator Issues #13119: Kirby Air Ride texture behavior does not match original hardwarehttps://bugs.dolphin-emu.org/issues/13119?journal_id=7461482023-04-18T21:52:13Zpokechu22
<ul></ul><p>Probably related: <a href="https://web.archive.org/web/20160304190627/https://www.opengl.org/archives/resources/faq/technical/clipping.htm" class="external">https://web.archive.org/web/20160304190627/https://www.opengl.org/archives/resources/faq/technical/clipping.htm</a> section "10.040 When an OpenGL primitive moves placing one vertex outside the window, suddenly the color or texture mapping is incorrect. What's going on?"</p>