Hi guys - as a CRT enthusiast I've been pondering something that I haven't seen addressed on the forum yet. I thought I'd air my thought process to see if anyone knows of any leads..
When playing the Wii on a CRT, the very best image is achieved using 480p on a progressive scan CRT that can output true 480p with no upscaling or image processing of any kind. If the TV is properly set up and hasn't had too much use, the image is stunning - but these CRTs were never that common and are now quite hard to find.
There's one aspect to these displays that define the CRT look more than any other. It gives 480p games a wonderful texture - this is the unique quality of the 480p shadow mask. There are lots of great CRT shaders out there for 240p games, but I haven't seen any (at least for Dolphin), that are for 480p games. Of course a 240p shader would look totally wrong for these consoles.
Apart from the giving this unique textured look to the graphics, the 480p shadow mask has a couple of other qualities that really benefit the Wii and GC's image. One is that it smooths out jaggies - something that's not an issue for Dolphin, being able to run in higher resolutions. Another, though, is that the combination of the low 480p resolution image and the shadow mask eliminates the otherwise obtrusive edges and joins of polygons.
That brings me to the only unpleasant side effect of the otherwise amazing ability to run these games at high resolution on Dolphin. Around the edges of game elements and also sometimes where in game objects join other objects, the sharp edges emphasizes the polygonal makeup to these games enough to detract a little from the otherwise amazing visuals.
The 480p shadow mask mitigates these sharp edges just enough to make give the look of a fully contiguous image, rather than an image made up of lots of polygons. Combined with the texture of the mask, you get an image with a unique solidity and depth, almost more than a sum of it's parts.
Part of the issue that creates this overly polygonal look in Dolphin is that the games are normally rendered at such a high resolution. So as well as adding a shadow mask filter, a good idea might be to lower the resolution a little. 480p would be much too regressive and would not be a good look on non-CRT displays. I think that on a 1080p display you might want to go with a 2x resolution - so something like 1280 x 960. That's enough to soften the edges of the polygons without being too low res for modern displays. The key is that even though a little sharpness is lost, it is partially replaced by the added definition provided by the shadow mask. So you are taking away a touch of resolution based sharpness by reducing the resolution a touch, but to counter that you're adding back definition in a different way - so as to create a well defined image without overly sharp edges. Much better than simply reducing resolution. I haven't been able to experiment with this kind of thing so maybe a different resolution would suit better - it would be a case of trial and error.
Then a bit of anti aliasing could be applied to reduce the already minimal jaggies. With a slightly less sharp but anti-aliased look, you have the perfect image style to lay a 480p CRT shader over. If you're using a really excellent CRT shader, a few things will be resolved and enhanced. Firstly, the shader will finish the job of eliminating the jaggies. Then, paradoxically, the image will actually look a little sharper/cleaner than before - the fine shadow mask texture adds definition to the image.
There are other elements that a very good CRT shader can do as well that will add to this - A non-linear brightness curve and real-time true phosphor emulation with actual per-phosphor bloom for example. In CRT terms, this is much more complex and involved than a simple bloom effect and/or placing a static mask over the image.
On another note, one of the problems with 240p CRT filters is that people tend to overuse them, trying to make them blurry and overly saturated to simulate a perceived look of an old blurry CRT with the contrast driven too high. In fact, properly calibrated high end CRTs didn't have that look at all when they were new (and properly calibrated). So to get the clean image we want for Dolphin the CRT shader should be used with precision and with care not to overdo it.
Finally, the ideal shader would be highly customizable, so as to be able to control the brightness curve, level of phosphor bloom, size and intensity of the mask etc. Some 240p shaders do an excellent job of this.
All of this is a matter of taste of course, and there will be lots of people who don't mind the overly polygonal effect and just love the super sharp look. But it would be fascinating to see this implemented in Dolphin and I think it would give a beautiful image - and an alternative that is already proven to suit these console's extremely well on CRTs - but with the higher resolution and other benefits Dolphin brings.
I know a reasonable amount about gaming on CRTs with real hardware but not so much about Dolphin, so if anyone knows of a shader like this that could be adapted for use in dolphin, or has any other info about this I would be really interested to hear..
When playing the Wii on a CRT, the very best image is achieved using 480p on a progressive scan CRT that can output true 480p with no upscaling or image processing of any kind. If the TV is properly set up and hasn't had too much use, the image is stunning - but these CRTs were never that common and are now quite hard to find.
There's one aspect to these displays that define the CRT look more than any other. It gives 480p games a wonderful texture - this is the unique quality of the 480p shadow mask. There are lots of great CRT shaders out there for 240p games, but I haven't seen any (at least for Dolphin), that are for 480p games. Of course a 240p shader would look totally wrong for these consoles.
Apart from the giving this unique textured look to the graphics, the 480p shadow mask has a couple of other qualities that really benefit the Wii and GC's image. One is that it smooths out jaggies - something that's not an issue for Dolphin, being able to run in higher resolutions. Another, though, is that the combination of the low 480p resolution image and the shadow mask eliminates the otherwise obtrusive edges and joins of polygons.
That brings me to the only unpleasant side effect of the otherwise amazing ability to run these games at high resolution on Dolphin. Around the edges of game elements and also sometimes where in game objects join other objects, the sharp edges emphasizes the polygonal makeup to these games enough to detract a little from the otherwise amazing visuals.
The 480p shadow mask mitigates these sharp edges just enough to make give the look of a fully contiguous image, rather than an image made up of lots of polygons. Combined with the texture of the mask, you get an image with a unique solidity and depth, almost more than a sum of it's parts.
Part of the issue that creates this overly polygonal look in Dolphin is that the games are normally rendered at such a high resolution. So as well as adding a shadow mask filter, a good idea might be to lower the resolution a little. 480p would be much too regressive and would not be a good look on non-CRT displays. I think that on a 1080p display you might want to go with a 2x resolution - so something like 1280 x 960. That's enough to soften the edges of the polygons without being too low res for modern displays. The key is that even though a little sharpness is lost, it is partially replaced by the added definition provided by the shadow mask. So you are taking away a touch of resolution based sharpness by reducing the resolution a touch, but to counter that you're adding back definition in a different way - so as to create a well defined image without overly sharp edges. Much better than simply reducing resolution. I haven't been able to experiment with this kind of thing so maybe a different resolution would suit better - it would be a case of trial and error.
Then a bit of anti aliasing could be applied to reduce the already minimal jaggies. With a slightly less sharp but anti-aliased look, you have the perfect image style to lay a 480p CRT shader over. If you're using a really excellent CRT shader, a few things will be resolved and enhanced. Firstly, the shader will finish the job of eliminating the jaggies. Then, paradoxically, the image will actually look a little sharper/cleaner than before - the fine shadow mask texture adds definition to the image.
There are other elements that a very good CRT shader can do as well that will add to this - A non-linear brightness curve and real-time true phosphor emulation with actual per-phosphor bloom for example. In CRT terms, this is much more complex and involved than a simple bloom effect and/or placing a static mask over the image.
On another note, one of the problems with 240p CRT filters is that people tend to overuse them, trying to make them blurry and overly saturated to simulate a perceived look of an old blurry CRT with the contrast driven too high. In fact, properly calibrated high end CRTs didn't have that look at all when they were new (and properly calibrated). So to get the clean image we want for Dolphin the CRT shader should be used with precision and with care not to overdo it.
Finally, the ideal shader would be highly customizable, so as to be able to control the brightness curve, level of phosphor bloom, size and intensity of the mask etc. Some 240p shaders do an excellent job of this.
All of this is a matter of taste of course, and there will be lots of people who don't mind the overly polygonal effect and just love the super sharp look. But it would be fascinating to see this implemented in Dolphin and I think it would give a beautiful image - and an alternative that is already proven to suit these console's extremely well on CRTs - but with the higher resolution and other benefits Dolphin brings.
I know a reasonable amount about gaming on CRTs with real hardware but not so much about Dolphin, so if anyone knows of a shader like this that could be adapted for use in dolphin, or has any other info about this I would be really interested to hear..