These look interesting. From LineSpecialGameInfo.vc:

	
	CEILING_VERTEX_HEIGHT_TYPE = 1505,
	SLOPE_FLOOR_POINT_LINE_TYPE = 9500,
	SLOPE_CEILING_POINT_LINE_TYPE = 9501,
	SET_FLOOR_SLOPE_TYPE = 9502,
	SET_CEILING_SLOPE_TYPE = 9503,
	COPY_FLOOR_PLANE_TYPE = 9510,
	COPY_CEILING_PLANE_TYPE = 9511;

Anyone have any thoughts on this? I'll try these out myself and report back.

Found something. [quote="someone at doomworld forum":302elvg2] Things 9500 and 9501: The first argument to these things is a line id. For each matching line, the sector on the same side of the line has its floor or ceiling sloped so that it passes through this thing. The thing does not necessarily need to be in the sector(s) being sloped. 9500 slopes the floor, and 9501 slopes the ceiling. Things 9502 and 9503: Set the plane equation for the sector they are in directly. The first argument determines how far it tilts from horizontal and is measured in degrees. 90 degrees is perfectly horizontal. Values close to 90 have less slope than values further from 90. The thing's angle is used to determine what direction the slope faces. The floor or ceiling will be adjusted so that it passes through this thing. 9502 slopes the floor, and 9503 slopes the ceiling. Things 9510 and 9511: The first argument to these is a sector tag. The plane equation from the first sector with a matching tag will be copied to the sector that this thing is in. 9510 copies the floor plane, and 9511 copies the ceiling plane. Things 9500-9503 are processed after slopes created with linedef specials, so they can be used to further adjust the resultant slope. Things 9510 and 9511 are processed after all other slopes are set up, so they override any slopes that might have been created in their sectors already. Should this be added to the wiki?

All of these things work. If nobody objects, I'll add this info to the wiki. edit: added to wiki.

Nice, I didn't knew these were supported <!-- s:D --><img src="{SMILIES_PATH}/icon_biggrin.gif" alt=":D" title="Very Happy" /><!-- s:D -->.