fixed node texture shifting bugs

src/renderer/buffers/nodes.rs

@@ -28,6 +28,7 @@ impl Nodes {
 
     pub fn set_node(&mut self, index: usize, value: u32) {
         self.node_buffer[self.active_buffer][index] = value;
+        self.modified = true;
     }
 
     pub fn shift(&mut self, offset: &Vector3<i32>) -> bool {
@@ -38,6 +39,10 @@ impl Nodes {
         let (ox, oy, oz) = (offset.x, offset.y, offset.z);
         let size = NODE_TEX_SIZE  as i32;
 
+        for i in self.node_buffer[b].iter_mut() {
+            *i = 0;
+        }
+
         for x in max(0, -ox)..min(size-ox, size) {
             for y in max(0, -oy)..min(size-oy, size) {
                 for z in max(0, -oz)..min(size-oz, size) {