diff --git a/shader/lighting/cap.geom b/shader/lighting/cap.geom
index 0de6d1868..eb0e6432d 100644
--- a/shader/lighting/cap.geom
+++ b/shader/lighting/cap.geom
@@ -3,6 +3,7 @@ layout (triangles) in;
 layout (triangle_strip, max_vertices = 3) out;
 layout (std140, binding = 0) uniform TheMat { mat4 theMat; } ;
 layout(location=0)uniform vec3 lightPos;
+in float drawbit[];
 // this code is duplicated in lineShadow.geom, should not be changed on its own
 vec4 projNear (vec4 pos)
 {
@@ -20,7 +21,8 @@ void main()
     vec4 p2 = gl_in[2].gl_Position ;
     if ( //if Light Source is below all vertices, draw cap 
         // TODO think about when LS is beside the object
-            ( p0.z - lightPos.z > 0 )
+            (drawbit[0] == 1)
+            && ( p0.z - lightPos.z > 0 )
             && ( p1.z - lightPos.z > 0 )
             && ( p2.z - lightPos.z > 0 )
             )
diff --git a/shader/lighting/cap.vert b/shader/lighting/cap.vert
index af25261ff..0be979d12 100644
--- a/shader/lighting/cap.vert
+++ b/shader/lighting/cap.vert
@@ -1,11 +1,11 @@
 #version 450 core
-layout (location = 0) in vec3 position;
+layout (location = 0) in vec4 position;
 layout (std140, binding = 0) uniform TheMat { mat4 theMat; } ;
 uniform vec3 lightPos;
 uniform vec4 lumRad;
-out vec3 dField;
-out vec3 lum;
+out float drawbit;
 void main()
 {
-    gl_Position = vec4(position,1);
+    gl_Position = vec4(position.xyz,1);
+    drawbit = position.w;
 }
diff --git a/src/Shader/Poke.hs b/src/Shader/Poke.hs
index bf4cb2fe5..eff910f66 100644
--- a/src/Shader/Poke.hs
+++ b/src/Shader/Poke.hs
@@ -133,7 +133,7 @@ pokeRoundedFaces ::
     IO (Int, Int, Int)
 {-# INLINE pokeRoundedFaces #-}
 pokeRoundedFaces sfid col size ptr iptr ieptr (nv, nsi, nei) (tc : bc : svs) = do
-    nv' <- pokeRoundedCurve col ptr tc bc svs nv
+    nv' <- pokeRoundedCurve xdata col ptr tc bc svs nv
     nsi' <-
         UV.foldM'
             (pokeIndex nv iptr)
@@ -143,6 +143,9 @@ pokeRoundedFaces sfid col size ptr iptr ieptr (nv, nsi, nei) (tc : bc : svs) = d
         else UV.foldM' (pokeIndex nv ieptr) nei $
             memoTopPrismEdgeIndices V.! (size - 3)
     return (nv', nsi', nei')
+  where
+    xdata | sfid = 0
+        | otherwise = 1
 pokeRoundedFaces _ _ _ _ _ _ _ _ = undefined
 
 pokeCylinder ::
@@ -157,7 +160,7 @@ pokeCylinder ::
     IO (Int, Int, Int)
 {-# INLINE pokeCylinder #-}
 pokeCylinder sfid col size ptr iptr ieptr (nv, nsi, nei) (tc : bc : svs) = do
-    nv' <- pokeRoundedCurve col ptr tc bc svs nv >>= pokeCylinderCaps col ptr tc bc svs
+    nv' <- pokeRoundedCurve xdata col ptr tc bc svs nv >>= pokeCylinderCaps xdata col ptr tc bc svs
     nsi' <-
         UV.foldM'
             (pokeIndex nv iptr)
@@ -168,21 +171,24 @@ pokeCylinder sfid col size ptr iptr ieptr (nv, nsi, nei) (tc : bc : svs) = do
         else UV.foldM' (pokeIndex nv ieptr) nei $
             memoTopPrismEdgeIndices V.! (size - 3)
     return (nv', nsi', nei')
+  where
+    xdata | sfid = 0
+        | otherwise = 1
 pokeCylinder _ _ _ _ _ _ _ _ = undefined
 
-pokeRoundedCurve :: Point4 -> Ptr Float -> Point3 -> Point3 -> [Point3] -> Int -> IO Int
+pokeRoundedCurve :: Float -> Point4 -> Ptr Float -> Point3 -> Point3 -> [Point3] -> Int -> IO Int
 {-# INLINE pokeRoundedCurve #-}
-pokeRoundedCurve col ptr tc bc = go True
+pokeRoundedCurve xdata col ptr tc bc = go True
   where
-    go True  (x : xs) n = pokeJustV tc col ptr n x >>= go False xs
-    go False (x : xs) n = pokeJustV bc col ptr n x >>= go True  xs
+    go True  (x : xs) n = pokeJustV xdata tc col ptr n x >>= go False xs
+    go False (x : xs) n = pokeJustV xdata bc col ptr n x >>= go True  xs
     go _ [] n = return n
 
-pokeCylinderCaps :: Point4 -> Ptr Float -> Point3 -> Point3 -> [Point3] -> Int -> IO Int
-pokeCylinderCaps col ptr tc bc = go True
+pokeCylinderCaps :: Float -> Point4 -> Ptr Float -> Point3 -> Point3 -> [Point3] -> Int -> IO Int
+pokeCylinderCaps xdata col ptr tc bc = go True
   where
-    go True (x : xs) n = pokeJustVInvNormal tc col ptr n x >>= go False xs
-    go False (x : xs) n = pokeJustVInvNormal bc col ptr n x >>= go True xs
+    go True (x : xs) n = pokeJustVInvNormal xdata tc col ptr n x >>= go False xs
+    go False (x : xs) n = pokeJustVInvNormal xdata bc col ptr n x >>= go True xs
     go _ [] n = return n
 
 pokeBox ::
@@ -197,7 +203,7 @@ pokeBox ::
     IO (Int, Int, Int)
 {-# INLINE pokeBox #-}
 pokeBox sfid col size ptr iptr ieptr (nv, nsi, nei) svs = do
-    nv' <- VFSM.foldM' (pokeBoxSurface col ptr svsv) nv $ VFSM.fromList $ boxSurfaces size
+    nv' <- VFSM.foldM' (pokeBoxSurface xdata col ptr svsv) nv $ VFSM.fromList $ boxSurfaces size
     nsi' <-
         UV.foldM'
             (pokeIndex nv iptr)
@@ -209,12 +215,14 @@ pokeBox sfid col size ptr iptr ieptr (nv, nsi, nei) svs = do
     return (nv', nsi', nei')
   where
     svsv = UV.fromList svs
+    xdata | sfid = 0
+        | otherwise = 1
 
 -- should probably use a vector of Point3
-pokeBoxSurface :: Point4 -> Ptr Float -> UV.Vector Point3 -> Int -> [Int] -> IO Int
-pokeBoxSurface col ptr vs n is =
+pokeBoxSurface :: Float -> Point4 -> Ptr Float -> UV.Vector Point3 -> Int -> [Int] -> IO Int
+pokeBoxSurface xdata col ptr vs n is =
     UV.foldM'
-        (pokeFlatV norm col ptr)
+        (pokeFlatV xdata norm col ptr)
         n
         v
   where
@@ -346,6 +354,7 @@ topPrismIndices n =
 -- and just doing two pokes rather than seven
 -- (especially if adding normal data)
 pokeJustV ::
+    Float ->
     Point3 ->
     Point4 ->
     Ptr Float ->
@@ -353,8 +362,8 @@ pokeJustV ::
     Point3 ->
     IO Int
 {-# INLINE pokeJustV #-}
-pokeJustV cp col ptr nv sh = do
-    UV.imapM_ f $ UV.fromList [x, y, z, 1, r, g, b, a, nx, ny, nz, 1]
+pokeJustV xdata cp col ptr nv sh = do
+    UV.imapM_ f $ UV.fromList [x, y, z, xdata, r, g, b, a, nx, ny, nz, 1]
     return (nv + 1)
   where
     f i = pokeElemOff ptr (nv * nShapeVerxComp + i)
@@ -363,6 +372,7 @@ pokeJustV cp col ptr nv sh = do
     V3 nx ny nz = cp
 
 pokeJustVInvNormal ::
+    Float ->
     Point3 ->
     Point4 ->
     Ptr Float ->
@@ -370,8 +380,8 @@ pokeJustVInvNormal ::
     Point3 ->
     IO Int
 {-# INLINE pokeJustVInvNormal #-}
-pokeJustVInvNormal cp col ptr nv sh = do
-    UV.imapM_ f $ UV.fromList [x, y, z, 1, r, g, b, a, nx, ny, nz, 1]
+pokeJustVInvNormal xdata cp col ptr nv sh = do
+    UV.imapM_ f $ UV.fromList [x, y, z, xdata, r, g, b, a, nx, ny, nz, 1]
     return (nv + 1)
   where
     f i = pokeElemOff ptr (nv * nShapeVerxComp + i)
@@ -380,6 +390,7 @@ pokeJustVInvNormal cp col ptr nv sh = do
     V3 nx ny nz = (2 * sh) - cp
 
 pokeFlatV ::
+    Float ->
     Point3 ->
     Point4 ->
     Ptr Float ->
@@ -387,8 +398,8 @@ pokeFlatV ::
     Point3 ->
     IO Int
 {-# INLINE pokeFlatV #-}
-pokeFlatV norm col ptr nv sh = do
-    UV.imapM_ f $ UV.fromList [x, y, z, 1, r, g, b, a, nx, ny, nz, 1]
+pokeFlatV xdata norm col ptr nv sh = do
+    UV.imapM_ f $ UV.fromList [x, y, z, xdata, r, g, b, a, nx, ny, nz, 1]
     return (nv + 1)
   where
     f i = pokeElemOff ptr (nv * nShapeVerxComp + i)