diff --git a/leenkx/blender/lnx/material/make_mesh.py b/leenkx/blender/lnx/material/make_mesh.py
index 082b6f7..6054fbd 100644
--- a/leenkx/blender/lnx/material/make_mesh.py
+++ b/leenkx/blender/lnx/material/make_mesh.py
@@ -715,6 +715,7 @@ def make_forward_base(con_mesh, parse_opacity=False, transluc_pass=False):
         frag.write('vec3 indirect = envl;')
 
     if '_VoxelGI' in wrd.world_defs:
+        frag.write('vec2 velocity = gl_FragCoord.xy;')
         frag.write('vec4 diffuse_indirect = traceDiffuse(wposition, n, voxels, clipmaps);')
         frag.write('indirect = (diffuse_indirect.rgb * albedo * (1.0 - F) + envl * (1.0 - diffuse_indirect.a)) * voxelgiDiff;')
         frag.write('if (roughness < 1.0 && specular > 0.0) {')