RaycastMatID

macroScript RaycastMatID
category:"PoC"
tooltip:"Raycast MatID"
(
    fn getFaceMatIDFromNode node faceIndex = (
        local matID = undefined
        if faceIndex != undefined do (
            -- Primary method: Standard Mesh
            -- getFaceMatID works reliably on Editable_Mesh nodes.
            if (isKindOf node Editable_Mesh) or (classOf node == TriMesh) then (
                try ( matID = getFaceMatID node faceIndex ) catch ()
            )
            -- If it's a Poly, we usually can't trust the FaceIndex (tri) against the Poly structure directly
            -- without converting the Poly to Mesh first.
            -- So we return undefined, and let the caller handle the layout conversion (via snapshot/fallback).
        )
        matID
    )

    on execute do (
        clearListener()

        local mousePos = mouse.pos
        local viewRay = mapScreenToWorldRay mousePos

        local hits = intersectRayScene viewRay

        if hits.count == 0 then ( print "No hit"; return () )

        local closestNode = undefined
        local closestDist = 1.0e9

        for h in hits do (
            local hitNode = h[1]
            local hitRay = h[2]
            if not hitNode.isHidden do (
                local d = distance viewRay.pos hitRay.pos
                if d < closestDist do (
                    closestDist = d
                    closestNode = hitNode
                )
            )
        )

        if closestNode == undefined then ( print "No hit (all hidden?)"; return () )

        -- format "Hit: % class=%\n" closestNode.name (classOf closestNode)

        local isVRayProxy = matchPattern ((classOf closestNode) as string) pattern:"*VRayProxy*"

        if not isVRayProxy then (
            -- NORMAL MESH/POLY PATH
            local tStart = timeStamp()
            local exHit = intersectRayEx closestNode viewRay

            local faceIdx = "NA"
            local mID = "NA"
            local status = "FAIL"

            -- Helper to process a successful hit on a node
            fn processHit theNode theHit = (
                local f = theHit[2] -- face index
                local id = getFaceMatIDFromNode theNode f
                #(f, id)
            )

            if exHit != undefined then (
                faceIdx = exHit[2]
                local res = processHit closestNode exHit
                if res[2] != undefined then (
                    mID = res[2]
                    status = "OK"
                ) else (
                    -- Hit existed, but checking MatID on this specific node type failed (e.g. Poly).
                    -- Fall through to fallback
                    status = "NeedMeshFallback"
                )
            ) else (
                status = "RayMissedGeo"
            )

            -- FALLBACK: If we missed OR if we couldn't get MatID (Poly), try snapshot
            if status == "RayMissedGeo" or status == "NeedMeshFallback" then (
                try (
                    -- snapshot creates a NEW temp NODE that is a collapsed Editable Mesh
                    local tempMeshNode = snapshot closestNode

                    local exHitMesh = intersectRayEx tempMeshNode viewRay
                    if exHitMesh != undefined then (
                        faceIdx = exHitMesh[2]
                        mID = getFaceMatIDFromNode tempMeshNode faceIdx
                        status = "OK_ViaMesh"
                    ) else (
                        status = "RayMissedGeo_EvenAsMesh"
                    )
                    delete tempMeshNode
                ) catch (
                    status = "FallbackException"
                )
            )

            local tEnd = timeStamp()
            local dt = tEnd - tStart
            format "Hit: % class=% dt=%ms face=% matID=%\n" closestNode.name (classOf closestNode) dt faceIdx mID

        ) else (
            -- VRAYPROXY PATH
            local proxyNode = closestNode

            -- APPROACH A: vrayMeshImport()
            local tA0 = timeStamp()
            local resA_Face = "NA"
            local resA_MatID = "NA"
            local resA_Count = 0
            local statusA = "FAIL"

            try (
                local oldSel = selection as array
                select proxyNode

                local imported = undefined
                try ( imported = vrayMeshImport() ) catch ( statusA = "FuncNotFound" )

                if imported != undefined and classOf imported == Array and imported.count > 0 then (
                    resA_Count = imported.count
                    local meshObj = imported[1]
                    meshObj.transform = proxyNode.transform

                    local exHit = intersectRayEx meshObj viewRay
                    if exHit != undefined then (
                        resA_Face = exHit[2]
                        local foundID = getFaceMatIDFromNode meshObj resA_Face
                        if foundID != undefined then resA_MatID = foundID
                        statusA = "OK"
                    ) else ( statusA = "MissedImportMesh" )

                    delete imported
                ) else (
                    if statusA != "FuncNotFound" then statusA = "ImportReturnedEmpty"
                )
                select oldSel
            ) catch ( statusA = "Exception: " + (getCurrentException()) )

            local tA1 = timeStamp()
            local dtA = tA1 - tA0
            format "ApproachA: dt=%ms, face=%, matID=%, importedMeshes=%, status=%\n" dtA resA_Face resA_MatID resA_Count statusA


            -- APPROACH B: Snapshot (Display Mesh + EditPoly + Snapshot)
            local tB0 = timeStamp()
            local resB_Face = "NA"
            local resB_MatID = "NA"
            local statusB = "FAIL"
            local oldDisplay = undefined
            local modAdded = undefined

            try (
                if isProperty proxyNode #display then (
                    oldDisplay = proxyNode.display
                    proxyNode.display = 3 -- Whole mesh
                )

                modAdded = Edit_Poly()
                addModifier proxyNode modAdded

                -- Create a snapshot NODE (Editable Mesh) of this state
                -- This treats it 'like a normal mesh' for the raycaster
                local tempNode = snapshot proxyNode

                local exHit = intersectRayEx tempNode viewRay
                if exHit != undefined then (
                    resB_Face = exHit[2]
                    resB_MatID = getFaceMatIDFromNode tempNode resB_Face
                    statusB = "OK"
                ) else (
                    statusB = "MissedSnapshot"
                )

                delete tempNode

            ) catch ( statusB = "Exception: " + (getCurrentException()) )

            -- Cleanup B
            if modAdded != undefined do (
                local modIndex = undefined
                for m = 1 to proxyNode.modifiers.count do (
                    if proxyNode.modifiers[m] == modAdded do modIndex = m
                )
                if modIndex != undefined do deleteModifier proxyNode modIndex
            )
            if oldDisplay != undefined do proxyNode.display = oldDisplay

            local tB1 = timeStamp()
            local dtB = tB1 - tB0
            format "ApproachB: dt=%ms, face=%, matID=%, status=%\n" dtB resB_Face resB_MatID statusB
        )
    )
)