Editing Property transfer linedef types
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=== New to MBF === | === New to MBF === | ||
271 Ext -- Transfer sky texture to tagged sectors | |||
272 Ext -- Transfer sky texture to tagged sectors, flipped | |||
These linedefs transfer wall textures to skies. F_SKY1 must still be used as the floor or ceiling texture in the sectors for which sky is desired, but the presence of a 271 or 272 property-transfer linedef can change the sky texture to something other than a level-based default. | |||
Every sector with F_SKY1 floor or ceiling which shares the same sector tag as the 271 or 272 linedef will use a sky texture based on the upper texture of the first sidedef in the 271 or 272 linedef. Sectors with F_SKY1 floors or ceilings which are not tagged with 271 or 272 linedefs, behave just like Doom. | |||
Horizontal offsets or scrolling in the transferred texture, is converted into rotation of the sky texture. Vertical offsets or scrolling is transferred as well, allowing for precise adjustments of sky position. Unpegging in the sky transfer linedef does not affect the sky texture. | |||
Horizontal scrolling of the transferred upper wall texture is converted into rotation of the sky texture, but it occurs at a very slow speed relative to the moving texture, allowing for long-period rotations (such as one complete revolution per Doom real-time hour). | |||
Effects other than sky-transfer effects are not excluded from the affected sector(s), and tags can be shared so long as the effects are unambiguous. For example, a wall-scrolling linedef can share a sector tag with both its affectee linedef (the one being scrolled), and with the sector that the latter controls. There is no ambiguity because one effect (scrolling) applies to a linedef, while the other effect (sky transfer) applies to a sector. | |||
If a sector underneath a special sky needs to be set up to have a different purpose (for example, if it is a lift or a stairbuilder), then two tags will need to be created, and the transfer linedef and any scrolling linedefs will need to be duplicated as well, so that the same effect as far as the sky goes, is duplicated in two separate sector tags. This will not affect sky appearance, but it will allow a special sector which needs a unique tag, to sit under such a sky. | |||
Animated textures may be transferred to skies as well. | |||
In Doom, skies were flipped horizontally. To maintain compatibility with this practice, the 272 linedef flips the wall image horizontally. The 271 linedef does not flip the wall image, and it is intended to make it easier to take existing non-flipped wall textures and transfer them to skies. | |||
Sky textures which are different must be separated by non-sky textures, or else the results are undefined. | |||
Note for Eternity Engine v3.31 public beta 6 and later: Sky textures will be rendered using the maximum of the texture height and the height of the tallest patch in the texture, in order to properly support tall skies that do not require stretching for mlook. Because of this, textures which are meant to cut off a taller patch at the texture height will not appear as expected when used as sky textures. Avoid using sky textures which contain patches taller than the texture to avoid this problem. | |||
==Constant pushers== | ==Constant pushers== | ||
