by Enjay » Thu Jul 19, 2018 2:12 pm
Part of the problem is that the skin sprites are in Doom format. This format does not contain its own palette but, rather, each point in the image is mapped to a location on the game palette. Change the palette and the appearance (colour) of the image displayed will change. That's what happens when you load the skin in Heretic, it's using Doom palette references, but these are being mapped against the Heretic palette and these are mostly not suitable 1 for 1 replacemsnts with regards to palette order etc.
If you convert the sprites to PNG format (Slade can do this reasonably simply), then GZDoom will do a better job of displaying them because it will use the colours in the PNG and try to map them to the game palette*. This can be a bit hit or miss for an image intended for another game but usually it works out quite well. The biggest concern in this situation is that Doom player skins with a lot of green often don't work out very well in Heretic and certain player colour options can look quite bad. However, on this particular skin, the colour-adjustable green area is limited to the narrow bands of colour on the shoulder pads, so it will probably work out reasonably well.
*Non-player PNG sprites do not get mapped at all in GZDoom - they just use their own colours, but the player sprites are handled differently to accommodate the ability to adjust colours.
For illustration - a Doom skin, in Doom graphics format, in Heretic:
Spoiler:
The same skin converted to PNG format, still in Heretic:
Spoiler:
Messing with the colour sliders to make the green problem less obvious (also still in Heretic):
Spoiler:
[edit] Oh, and of course, what it looks like in Doom - it's a very green sprite:
Spoiler:
Part of the problem is that the skin sprites are in Doom format. This format does not contain its own palette but, rather, each point in the image is mapped to a location on the game palette. Change the palette and the appearance (colour) of the image displayed will change. That's what happens when you load the skin in Heretic, it's using Doom palette references, but these are being mapped against the Heretic palette and these are mostly not suitable 1 for 1 replacemsnts with regards to palette order etc.
If you convert the sprites to PNG format (Slade can do this reasonably simply), then GZDoom will do a better job of displaying them because it will use the colours in the PNG and try to map them to the game palette*. This can be a bit hit or miss for an image intended for another game but usually it works out quite well. The biggest concern in this situation is that Doom player skins with a lot of green often don't work out very well in Heretic and certain player colour options can look quite bad. However, on this particular skin, the colour-adjustable green area is limited to the narrow bands of colour on the shoulder pads, so it will probably work out reasonably well.
*Non-player PNG sprites do not get mapped at all in GZDoom - they just use their own colours, but the player sprites are handled differently to accommodate the ability to adjust colours.
For illustration - a Doom skin, in Doom graphics format, in Heretic:
[spoiler][img]https://i.imgur.com/RdAMgpg.png[/img][/spoiler]
The same skin converted to PNG format, still in Heretic:
[spoiler][img]https://i.imgur.com/pPWK7zs.png[/img][/spoiler]
Messing with the colour sliders to make the green problem less obvious (also still in Heretic):
[spoiler][img]https://i.imgur.com/u1sMX2c.png[/img][/spoiler]
[edit] Oh, and of course, what it looks like in Doom - it's a very green sprite:
[spoiler][img]https://i.imgur.com/qRKyy2M.png[/img][/spoiler]