<function name="TraceLine" parent="util" type="libraryfunc"> <description> Performs an infinitely thin, invisible ray trace (or "trace") in a line based on the input and returns a table that contains information about what, if anything, the trace line hit or intersected. Traces intersect with the physics meshes of <page text="solid">enums/SOLID</page>, <page text="server-side">States</page>, <page text="entities">Entity</page> (including the <page text="game world">game.GetWorld</page>) but cannot detect client-side only entities unless <page text="hitclientonly">Structures/Trace#hitclientonly</page> is set to true. See <page>ents.FindAlongRay</page> if you wish for the trace to not stop on first intersection. See <page>util.TraceHull</page> for a "box" type trace. Traces do not differentiate between the inside and the outside faces of physics meshes. Because of this, if a trace starts within a solid physics mesh it will hit the inside faces of the physics mesh and may return unexpected values as a result. You can use `r_visualizetraces` set to `1` (requires `sv_cheats` set to `1`) to visualize traces in real time for debugging purposes. </description> <realm>Shared</realm> <args> <arg name="traceConfig" type="table{Trace}"> A table of data that configures the trace. See <page>Structures/Trace</page> for available options. </arg> </args> <rets> <ret name="" type="table{TraceResult}"> A table of information detailing where and what the trace line intersected, or `nil` if the trace is being done before the <page>GM:InitPostEntity</page> hook. For the table's format and available options see the <page>Structures/TraceResult</page> page. </ret> </rets> </function> <example> <description>Using a function callback as filter.</description> <code> concommand.Add( "testTrace", function( ply ) local tr = util.TraceLine( { start = ply:GetShootPos(), endpos = ply:GetShootPos() + ply:GetAimVector() * 10000, filter = function( ent ) return ( ent:GetClass() == "prop_physics" ) end } ) print( tr.HitPos, tr.Entity ) end ) </code> <output>The trace will only hit prop_physics or world.</output> </example> <example> <description>Visualizes a trace.</description> <code> local color_red = Color( 255, 0, 0 ) local color_blu = Color( 0, 0, 255 ) local mins, maxs = Vector( -24, -3, -2 ), Vector( 24, 3, 2 ) hook.Add( "PostDrawTranslucentRenderables", "trace_visualize", function() local eyePos = Entity( 1 ):EyePos() + Entity( 1 ):GetRight() * -5 local eyeDir = Entity( 1 ):GetAimVector() local tr = util.TraceLine( { start = eyePos, endpos = eyePos + eyeDir * 10000, filter = Entity( 1 ) } ) render.DrawLine( eyePos + LocalPlayer():GetRight() * -5, tr.HitPos, color_red, true ) -- Show that the traceline is a line, not a hull render.DrawWireframeBox( tr.HitPos, Angle( 0, 0, 0 ), mins, maxs, color_red, true ) eyePos = Entity( 1 ):EyePos() + Entity( 1 ):GetRight() * 5 local tr2 = util.TraceHull( { start = eyePos, endpos = eyePos + eyeDir * 10000, filter = Entity( 1 ), mins = mins, maxs = maxs } ) render.DrawLine( eyePos, tr2.HitPos, color_blu, true ) render.DrawWireframeBox( tr2.HitPos, Angle( 0, 0, 0 ), mins, maxs, color_blu, true ) end ) </code> <output><upload src="70c/8dbdae6fcf05200.png" size="5612891" name="image.png" /></output> </example></example>⤶ ⤶ <example>⤶ <description>Example code that would hit clientside-only entities when ran on client.</description>⤶ <code>⤶ if ( CLIENT ) then⤶ concommand.Add( "test_cl_trace", function( ply )⤶ local tr = util.TraceLine( {⤶ start = ply:GetShootPos(),⤶ endpos = ply:GetShootPos() + ply:GetAimVector() * 10000,⤶ mask = MASK_ALL, -- This is needed to hit ragdolls of dead NPCs/players, since they are considered "debris"⤶ filter = ply, -- Don't this the player doing the trace⤶ hitclientonly = true -- Hit clientside only entites⤶ } )⤶ ⤶ -- Display trace results⤶ PrintTable( tr )⤶ ⤶ -- With "developer 1" enabled, draw the hit position⤶ -- The timer is necessary because debugoverlay won't work when the game is paused (such as when the console is open)⤶ timer.Simple( 0.0, function()⤶ debugoverlay.Cross( tr.HitPos, 16, 10 )⤶ debugoverlay.Text( tr.HitPos, "Hit: " .. tostring(tr.Entity), 10 )⤶ end )⤶ end )⤶ end⤶ </code>⤶ <output></output>⤶ </example>⤶