First setup to upload brush models (specifically: the world model) from Quake to Unity. Updated the QWorld class to include the fields added by QuakeSpasm.

Assets/Scripts/Data/QModel.cs

@@ -13,6 +13,7 @@ public class QModel
     private const int MaxMapHulls = 4;  // Should correspond to MAX_MAP_HULLS
     
     [MarshalAs(UnmanagedType.ByValTStr, SizeConst = MaxPath)] public string name;
+    public uint pathId;
     public bool needLoad;
     
     public QModelType type;
@@ -23,7 +24,8 @@ public class QModel
 
     // Volume occupied by the model graphics
     public QVec3 mins, maxs;
-    public float radius;
+    public QVec3 ymins, ymaxs;
+    public QVec3 rmins, rmaxs;
 
     // Solid volume for clipping
     public bool clipBox;
@@ -74,6 +76,15 @@ public class QModel
     public IntPtr lightData;    // Array of bytes
     [MarshalAs(UnmanagedType.LPStr)] public string entities;
 
+    public bool visWarn;
+    public int bspVersion;
+
+    public uint meshvbo;
+    public uint meshIndexesVbo;
+    public int vboIndexOfs;
+    public int vboXyzOfs;
+    public int vboStofs;
+
     public IntPtr userCache;
 }
 

Assets/Scripts/Modules/RenderModule.Interop.cs

@@ -14,6 +14,7 @@ public partial class RenderModule: CallbackHandler<RenderModule>
             target = TargetPtr,
 
             UploadAliasModel = CreateCallback<UploadAliasModelCallback>(Callback_UploadAliasModel),
+            UploadBrushModel = CreateCallback<UploadBrushModelCallback>(Callback_UploadBrushModel),
         };
 
         RegisterCallbacks(callbacks);
@@ -28,6 +29,7 @@ public partial class RenderModule: CallbackHandler<RenderModule>
         public IntPtr target;
 
         public IntPtr UploadAliasModel;
+        public IntPtr UploadBrushModel;
     }
 
     [UnmanagedFunctionPointer(CallingConvention.Cdecl, CharSet = CharSet.Ansi)]
@@ -63,4 +65,13 @@ public partial class RenderModule: CallbackHandler<RenderModule>
             triangles.ToStructArray<QTriangle>(header.numTriangles),
             stVerts.ToStructArray<QSTVert>(header.numVerts));
     }
+
+    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
+    private delegate int UploadBrushModelCallback(IntPtr target, QModel model);
+
+    [MonoPInvokeCallback(typeof(UploadBrushModelCallback))]
+    private static int Callback_UploadBrushModel(IntPtr target, QModel model)
+    {
+        return GetSelf(target).UploadBrushModel(model);
+    }
 }

Assets/Scripts/Modules/RenderModule.cs

@@ -70,4 +70,13 @@ public partial class RenderModule
         xPos += 0.5f;
         return 1;
     }
+    
+    private int UploadBrushModel(QModel model)
+    {
+        if (model.type != QModelType.Brush)
+            return -1;
+        
+        Debug.Log($"Brush model '{model.name}' with {model.numLeafs} leafs, {model.numVertices} vertices, {model.numSurfaces} surfaces");
+        return 1;
+    }
 }

engine/Quake/gl_model.h

@@ -517,5 +517,6 @@ byte	*Mod_NoVisPVS (qmodel_t *model);
 void Mod_SetExtraFlags (qmodel_t *mod);
 
 int UQ_GL_UploadAliasModel(qmodel_t *model, aliashdr_t *aliashdr, trivertx_t **poseVerts, mtriangle_t *triangles, stvert_t *stVerts);
+int UQ_GL_UploadBrushModel(qmodel_t *model);
 
 #endif	// __MODEL__

engine/Quake/gl_rmisc.c

@@ -401,6 +401,8 @@ void R_NewMap (void)
 	GL_BuildBModelVertexBuffer ();
 	//ericw -- no longer load alias models into a VBO here, it's done in Mod_LoadAliasModel
 
+	UQ_GL_UploadBrushModel(cl.worldmodel);
+
 	r_framecount = 0; //johnfitz -- paranoid?
 	r_visframecount = 0; //johnfitz -- paranoid?
 

engine/UniQuake/gl_uniquake.c

@@ -11,6 +11,7 @@ typedef struct unity_glcalls_s
 	void *target;
 
 	int(*UploadAliasModel)(void *target, const char *name, aliashdr_t *aliashdr, maliasframedesc_t *frames, trivertx_t **poseVerts, mtriangle_t *triangles, stvert_t *stVerts);
+	int(*UploadBrushModel)(void *target, qmodel_t *model);
 } unity_glcalls_t;
 
 const unity_glcalls_t *unity_glcalls;
@@ -21,3 +22,8 @@ int UQ_GL_UploadAliasModel(qmodel_t *model, aliashdr_t *aliashdr, trivertx_t **p
 	// so we pass along the pointer to the first frame struct which allows us to manually marshal the entire array.
 	return unity_glcalls->UploadAliasModel(unity_glcalls->target, model->name, aliashdr, &aliashdr->frames[0], poseVerts, triangles, stVerts);
 }
+
+int UQ_GL_UploadBrushModel(qmodel_t *model)
+{
+	return unity_glcalls->UploadBrushModel(unity_glcalls->target, model);
+}