I'm practicing with the Build modifier. I understand its basic functionality but I can not figure out, why it starts revealing one section of the mesh from the top, and the next section on the bottom and finally starts to build up the model.

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Q: Is there a way just to get the modifier to build up from one direction?


1 Answer 1


The Build Modifier will use the vertices index number to determine their apparition order. These indices are determined by their order of creation. In your case, if the Build modifier displays the top, then the bottom, then the rest, it's probably because you've created the horizontal edge loops with a bevel operation. With successive extrusions the order will have gone from top to bottom.

To display the Indices option in 2.9, enable Preferences > Interface > Developer Extras, then go in Edit Mode, select the vertices and enable the Indices option in the Viewport Overlays panel.

To sort the vertices the way you want, go in Edit Mode, put the 3D Cursor where you want, it will determine the last numbers, select all, in Mesh > Sort Elements > Cursor Distance, then in the Operator box click on the Face button.

For more complicated objects than simple vertical/horizontal ones there must be some addons or python codes that allow to sort the vertices index numbers.

You can play with the Build modifier Start value, if you want the object to be deconstructed instead of constructed, click on Reversed.

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  • $\begingroup$ Yep, that certainly worked great, just one thing though. I cannot find the indices you told me in the overlay panel. I googled and saw a few screenshots, but cannot find in my blender 2.91. On the left is my overlay panel, and on the right is the one from google. Where is the feature not residing? I tried to google it and nothing seems to show it. ibb.co/NTtdpJX $\endgroup$ Dec 26, 2020 at 8:41
  • $\begingroup$ Ok I've edited my answer $\endgroup$
    – moonboots
    Dec 26, 2020 at 8:56
  • $\begingroup$ @moonboots Thanks a lot I didnt know about the "Sort Elements" abilities :) Great to know :) Just it doesn't seem to have an effect to Build modifier for me, tested 2.82 and 2.92. $\endgroup$
    – vklidu
    Dec 26, 2020 at 12:51
  • $\begingroup$ mmh yes it has an effect, you must miss a step. Too bad it's not easier to choose the vertex index though... $\endgroup$
    – moonboots
    Dec 26, 2020 at 12:57
  • $\begingroup$ wow....how great is that?!!!!!! $\endgroup$
    – Chris
    Dec 26, 2020 at 13:08

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