[Plugin] Fix Reversed Face Materials

Rich O Brien

Thanks

I've a file that doesn't remove backface materials

TIG

Thanks
I've a file that doesn't remove backface materials

Let's see it - PM if needed...
Is it perhaps a group/instance where the back face is actually the default material but is displayed in the container's material ?

Rich O Brien

Too large for here. I'll email it.

TIG

Got it.
Where are the errant back faces with materials ?

TIG

Fixed it and emailed back to you... a material was applied to some group/instances, I used the Outliner and Entity Info to make it the default-material, then re-ran the tool to remove all back-face-materials - it seems OK now ?

JGA

Thanks

irwanwr

i might have a problem with the new version 1.5 20120216.
i don't know why and not sure either.
the last time i used this plugin, it can be accessed in context menu by right clicking.
but it seems that the new version would only available in the toolbar menu instead.
i just overwrite the previous version when installing this new one.

TIG

Iranwr

You are mistaken.
This toolset has never had any 'context-menu' options.
It has only ever worked from menu items.
This last update only combined all of the tools into one submenu, to avoid clutter etc.
Nothing else was done to the coding.
There is [and there never was] any code in the script regarding context-menus.
You also mention 'toolbar' - it never had a toolbar either - I suspect you actually meant 'menu' ??
OR perhaps you are thinking of another tool altogether ?

irwanwr

ah yes, sir.
i think i've made mistakes and confuse this tool with the other one.
and yes, what i meant was the menu bar.
sorry for bothering you with my mistakes.
i probably was thinking of that context menu feature if it's possible for this plugin.
obviously, it's not good to do modelling, thinking, reading and post a comment for feature request at around 4 am early in the morning.

TIG

Here's v1.6 http://forums.sketchucation.com/viewtopic.php?p=264134#p264134
It includes a new tool. If you have faces with different materials front and back and you would like the back to match the front use this tool...
Plugins > TIG: Reversed Face Tools... > Match Back-Materials
It will match all selected faces' back-materials with the front-materials,
maintaining UVmapping if the material is textured etc...
There is no reversing or flipping of faces - the back-material is simply matched
to the front-material.
Do not use this as an excuse for sloppy modeling!

utiler

Many thanks from Down Under, TIG!!!!

[That's a down under thumb BTW....]

Bob James

I use TheaRender and it is very fussy about flipped faces. Now suppose I build a complex model and somehow an odd assortment of faces (large and very small) are reversed. Is there an analogous plugin that will set all of the faces correctly before I apply any textures? (i.e.; all at the same time rather than having to go in and flip them one at a time).

TIG

Bob
Monochrome mode + a Style with a contrasting back-face material color... is good to check the correct orientation of faces.
The native Reverse 'flips' selected faces.
The native Orient tool ensures that all connected faces match a selected face's orientation, reversing those that don't comply.
However, if any face's edges are used by more than two faces then Orient can't succeed, because there is then no 'right answer' for those faces' orientation.
There are several scripts to 'reverse' faces, using different methods - picking, camera direction etc...
The Fix... toolset is specifically written to flip faces/materials that you have accidentally left reversed and have then textured on the backs - meaning your 3rd-party render application will probably render them white [or black] - as most renderers do not apply materials to 'back-faces' as these should always be unseen, being 'inside' objects...
The main Fix... tool finds all face in the current selection - with options to drill down into selected groups/instances and find those faces too - and if any of the faces have materials on their backs but no material on their front the faces are reversed, and their back material is reapplied onto the [now correctly oriented] front face, using the same UVmapping for any texture so that the appearance does not change at all, but the renderer will now happily use the material on the reversed face.
The latest tool matches back material to front materials, keeping matching UVmapping of textures - this way should you apply a textured material with say a transparent png image - like a latticework fence - it will be aligned on the faces' backs to match the fronts, and will appear correctly from both sides...

Dave R

Bob, TIG's point about Monochrome and the contrasting back face color is a good one. I use a green back face color to make it easier to pick out reversed faces and holes. It's a color I wouldn't normally use in practice and it is much easier to pick out than the default blue-gray.

I've got my default style and startup template set to show that green color. If you don't want to do that, you might setup a style with some obnoxious back face color to use during cleanup.

Perhaps the biggest thing to make the process easy is to stay on top of the reversed faces and fix them as you go. I think of it as good housekeeping. The biggest problem I have with reversed faces comes when I try to use components from the warehouse. As you know, there's an awful lot of crap there. It's pretty common to find components that are very sloppy in the way they are modeled. If it takes me more than a minute to fix a component I downloaded, I discard it and model it myself.

Bob James

TIG/Dave R,
Thank you for taking the time to address my question.

So the answer to my question is no: There is no ruby to examine an untextured model and reverse all faces that have the back face showing.

TIG

The texturing or otherwise of faces is irrelevant - a face's back is still its back, irrespective of its 'material' - Monochrome mode is a simple way to view things without materials...

How is any plugin going to know what is the 'right direction' for a given face?
The native Orient works fine on connected faces [that have edges with one or two faces each], making them all look the same way, but you must decide what is 'right' to start with.

Some of the scripts that are available do things like assume that if a visible face that is looking at the camera is a 'back-face' then if needs flipping, but again you'd need to decide where to position the camera to do this - put it inside a correctly oriented box and it'll turn inside out!

So there are tools to 'globally' flip reversed faces [I've made one!] - however, none of them will 'know' what is 'right' and you can end up with more effort using them than is needed if you've make shortcut-keys to Reverse/Orient with which you can then then quickly tidy faces selected faces as you model [another tip - a face that is highlighted by the PushPull tool [and some other tools too], before you click/pick it, can be Reversed using the shortcut key - so by simply 'hovering' over several faces in turn and pressing the shortcut key you can quickly Reverse faces without having to click/pick them at all!]. Using Monochrome mode with a Style having a distinctive back-face color [I use bright-blue, or sometimes magenta] helps a lot when doing this...

Bob James

Thanks, TIG. I ignorantly assummed that SU itself "knows" the orientation of faces since it applies the backface color to it; and, since it "knows" that, it should be possible to collectively flip those with the backface facing in the direction of the camera.

TIG

@bob james said:

Thanks, TIG. I ignorantly assummed that SU itself "knows" the orientation of faces since it applies the backface color to it; and, since it "knows" that, it should be possible to collectively flip those with the backface facing in the direction of the camera.
That's what some of the plugins do - i.e. they flip faces if their backs look towards the camera... but of course to fool that and get the wrong result, you just need to look from the 'other direction' - provided that you are always confident that you are looking the 'right way' then you should get all visible faces 'facing' the camera...

Rich O Brien

Could you hack a 'Normals toward camera' .rb?

say you select a region and run the tool and it put all normals towards the view. In Thomthom's Vertex Tools you can ignore 'backfaces' when you select. If this method was applied you could then run the 'normals toward' .rb to orient faces to camera.

Rich O Brien

I just realised my error in this thinking.... ....ignore