p2ce includes a new clustered renderer[p2ce.org], you can access the documentation to further understand it here: https://wiki.stratasource.org/lighting/clustered

the clustered renderer allows for dynamic lighting, which means moving light sources, real-time shadows, better specular, and light_dynamic can be completely forgotten (good riddance)

clustered is also fairly performant on older computers. of course, you'll still need to upgrade if your pc can barely run portal 2, but you won't need an expensive pc.

an example of clustered in use is Gentle Hum. shameless plug, deal with it.

light_rt // a new light entity to be used with clustered

light_rt_spot // light_rt but a spotlight

path_vphysics // works as an invisible funnel connected by a path. used for the vactubes in revo.

prop_testchamber_sign // info signs which are entirely editable in hammer, no longer requires editing a script on a per map basis.

info_portal_gamerules // changes various rules for gameplay.

schrödinger's cube (part of prop_weighted_cube) // the teleporty laser cube also used in revo.

give_paintgun // gives you a paint gun

upgrade_paintgun // gain all the paintgun paints (impulse 101 will also do this, along with the dual portal gun)

nextpaint / prevpaint // toggles between paints

paintallsurfaces 0-5 // paints all paintable surfaces in the map

+alt1 // swap between paint gun and portal gun

sv_force_enable_paint_in_map 1 // self explanatory, make sure to restart the map before it works.

ent_create_paint_bomb_reflect // spawns a reflection gel bomb

ent_create_paint_bomb_stick // spawns an adhesion gel bomb

cl_portal_alternate_colors // enables alternate portal colours (for next 2 commands)

cl_portal_sp_primary_color // changes the primary portal colour, format is rgb

cl_portal_sp_secondary_color // same as previous command, but with the secondary portal.

r_portal_use_dlights // not new but has been improved with clustered

r_portal_light_intensity // changes portal light intensity

cl_portal_use_new_dissolve // set to 0 to use p1 and hl2's old prop fizzle effect. set to 1 to use p2's

cl_dynamic_light_* // a range of commands to control the dynamic lights produced by energy pellets and turrets.

cl_portal_crosshair_mode // toggles between p1 and p2 crosshair behaviour.

sv_portal_legacy_compat // enables portal 1 legacy compatibility

player_throwenable // enables throwing props with +attack

player_throwforce // changes how hard you can throw props with +attack

cl_mirror_world // flips world rendering horizontally.

mv_duckjump // allows the player to jump while crouched

v_view_height // changes the player's view height (def. 64)

v_view_height_ducked # // changes the player view height while ducked (def. 28)

v_view_height_dead # // changes the player view height while dead (def. 14)

the player renders in water reflections now

parallax corrected cubemaps

you can colour lasers and funnels

you can mount other source games, just use mounts.kv in
you can now use panorama ui

new pbr shader

dx11 is now here, dx9 has been removed. vulkan is only available on linux.

engine tools have re-implemented

new (half-baked) physics engine, use -jolt launch command.

hammer is overall much more stable

hammeraddons is automatically included

mouse3 allows you to move the 3d camera in hammer

light preview exists but is currently broken

when rotating an object, an x will appear. you can change the rotation point of the object by moving it around.

there is a nodraw button on the small textures window to the right of the screen, this sets the current texture to nodraw.

some windows have been ported to qt, most notably the options and texture browser windows.