[Addon] Backface hiding

Updated to version 0.3 :
Implemented a button (and shortcut) to un-hide and restore your selection (which Alt+H doesn’t do)

Please. When I press “D” it happens …


I can’t reproduce this.
Do you have a regular mouse ?
Can we discuss about it live to solve this quicker ? see my signature below on where you can find me for live discussion.

tiny update : enabled Undo for each button so you can Ctrl+Z to cancel the operation and made them searcheable through the spacebar search.

If you find this add-on useful, consider upvoting it on blender.today

@JoseConseco I just tried your add-on and it does a pretty good job of hiding the backfacing geometry in real time.

Here are some drawbacks I found:

  • it doesn’t invert the effect if you flip the normals (if you want to model from the inside) because the hiding isn’t based on the face normals but rather on a distance from the unedited mesh (the high poly mesh), that distance being the “Offset” value in the add-on’s properties.
  • it doesn’t perform well on thin parts of your model (e.g. ears), again because of the offset base of this feature. You can use a smaller offset value but on a thin part you may have to decrease it to a point where you hide some front faces too if they are under the high-poly mesh.
  • if the scale of your model is very high (e.g. if you use the metric system at 0.01 for Unreal Engine export), the Offset clamp value of 1 is too low to be able to reveal the occluded geometry, making the add-on unusable.
  • so far it doesn’t work at all in 2.8, though we’d have to check again when 2.8 gets released.

my add-on doesn’t have all these issues but on the other hand, it doesn’t perform in real time, so a true Blender implementation would certainly give the best of both worlds.

1 Like

a) - you mean if you flip normal on hipoly or lowpoly? I checked flipping normal on lowpoly, and it seems to work ok. Same on hipoly I see nor problem.
b) I would need image example
c) I can fix that soon.
d) I’m not sure if there is new api for opengl drawing in blender 2.8. WIll see

a) Yes, on the lowpoly. I didn’t say it doesn’t work but it doesn’t invert the effect like we would expect it to. Other 3D programs - as well as my add-on - invert the effect, because their backface culling feature is based on whether a face normal is facing the camera or not.
b) watch this video:

another issue I just found:

  • if you hit numpad “.” to zoom on selection, the Draw Xray display gets all screwed up until you change your selection.

Finally, it would be better if you created a dedicated thread for your add-on because this discussion is off-topic here.

Just to notify that I moved the add-on (and all my repositories) to Gitlab. Link in first post that I just edited.
No news apart from that.
Well actually there’s one thing: the add-on doesn’t currently work in 2.8 but I think I’ll wait for the release to see if it’s still broken.

The great addon. Thanks

Can this be made possible for 2.81? I just want to be able to ignore or hide backfaces while selecting
https://streamable.com/s/pqscd/thatft

Ok I’ll try to update this for 2.8 this w-e.
btw your video doesn’t play.

2 Likes

Thanks!! what I want is being able to press a key, hide the back faces, do my selection and then press the key again to unhide and keep the selection. that would be awesome!! Or better yet but it would be more difficult is to create a circle select brush that would use select front faces only like the option all brushes have in sculpt mode.

sorry I over-estimated my availability. I will not be able to do this this w-e and I can’t guarantee anything about the next one. I’ll just do my best to do this asap.

Ok, thanks!

Finally, update for 2.8:

Notes:

  • supports multi-object editing
  • new operator to un-hide and keep current selection
  • changeable panel name in add-on prefs (so you can join it with any other)
  • shortcuts now using F5 to F8 (still changeable in add-on’s prefs)

I’m thinking that it would be better to just have one “Reveal” button that would keep the current selection on the visible geometry and restore the selection in the hidden part. Would you oppose that?

Also note that performance, while being the same as in 2.7x, could still be improved for high-poly meshes. If the Hide Backface operator is slow for your use case, feel free to tell me and I’ll I work on it (when I find the time).

Happy new year

4 Likes

I just tried to install the version 0.4 on Blender 2.82 Alpha (56ef761381ec - 2019-12-30) but I got this error message :

It happens each time I try to activate the addon.

My bad. That was just a folder name issue which I just fixed in the repository.

Since you’ve already put it in the config directory by using Blender’s Install button, you may either use the Remove button in the add-on’s preferences if available, then re-download the add-on, or otherwise go to the add-ons directory:
Linux: $HOME/.config/blender/2.81/scripts/addons/
Windows: %USERPROFILE%\AppData\Roaming\Blender Foundation\Blender\2.81\scripts\addons
Mac: /Users/$USER/Library/Application Support/Blender/2.81/scripts/addons/

and make sure my add-on is in a folder named Backface_Hiding and has no other folder inside.

Other than that, add-ons should generally not be expected to work on pre-release software, as it is always bound to change before the release, so any time spent fixing bugs there may be wasted.

This tool is SOOOOO Useful !
I REALLY NEEDED THIS during Retopology !
This effect is natural in 3ds max but the wireframe in Blender is a visual mess even in 2.81a !
THANK YOU !!!

Thanks for the feedback and you’re welcome! glad to know it’s useful to other people (゚⊿゚) :+1: