<function name="SetStencilPassOperation" parent="render" type="libraryfunc"> <description>Sets the operation to be performed on the stencil buffer values if the compare function was successful.</description> <realm>Client</realm>⤶ <realm>Client and Menu</realm>⤶ <args> <arg name="passOperation" type="number">Pass operation function, see <page>Enums/STENCILOPERATION</page>.</arg> </args> </function> <example> <description>This uses the pass operation to blank out everything but what we just drew (from [Lex's Stencil Tutorial](https://github.com/Lexicality/stencil-tutorial)).</description> <code> hook.Add( "PostDrawOpaqueRenderables", "Stencil Tutorial Example", function() -- Reset everything to known good render.SetStencilWriteMask( 0xFF ) render.SetStencilTestMask( 0xFF ) render.SetStencilReferenceValue( 0 ) render.SetStencilCompareFunction( STENCIL_ALWAYS ) render.SetStencilPassOperation( STENCIL_KEEP ) render.SetStencilFailOperation( STENCIL_KEEP ) render.SetStencilZFailOperation( STENCIL_KEEP ) render.ClearStencil() -- Enable stencils render.SetStencilEnable( true ) -- Set the reference value to 1. This is what the compare function tests against render.SetStencilReferenceValue( 1 ) -- Only draw things if their pixels are NOT 1. Currently this is everything. render.SetStencilCompareFunction( STENCIL_NOTEQUAL ) -- If something draws to the screen, set the pixels it draws to 1 render.SetStencilPassOperation( STENCIL_REPLACE ) -- Draw our entities. They will draw as normal for _, ent in ipairs( ents.FindByClass( "prop_physics" ) ) do ent:DrawModel() end -- At this point, we cannot draw on top of anything that we have already drawn. -- So, if we flush the screen, our entities will still be there. render.ClearBuffersObeyStencil( 0, 148, 133, 255, false ) -- Let everything render normally again render.SetStencilEnable( false ) end ) </code> <output><image src="basic_pass_operation.jpg" alt="800px"/></output> </example>