Am I too dumb to find the feature or isn´t it implemented and no one wrote a script yet for it?
I simply want to select several polys either adjacent or non adjacent and then either:
align them to the X, Y or Z-Plane, or
align them to the active poly
thanks in advance.
Lets assume u want to allign in X so you can use the mirror modifier and you want the verts directly on X = 0 so cliping will work properly. Select the verts you want to align scale to 0 by pressing the following sequence of keys KEY S, KEY X and KEY0. s=scale x=limit scale to x axis 0=scale to 0. This will align you vets on x so that they are paralel with the in the X axisbut may not be on x=0 to do this havingthe verts already selected press KEY N to bring up the transformation dialog box key in 0 for X Loc.
I am aware of this “workaround” but its only for aligning into X(0).
I´d rather like align in a plane parallel to X, Y or Z and something not destroying the whole topology or mesh. simply if a polygon isnt flat, flatten to one of the major planes and then rotate till its back where it belongs.
Even more imperative is the aligning to another plane. i made a small sketch, because i think i didnt express myself clearly enough. The idea is to align polygon B in the plane of polygon A, where polygon A is planar.
I know there is a make planar button in 3dsmax. something similar in blender?
No one? Well, as long as the vertices are parallel to one of the main planes (xyz) its not that hard, but once the plane is inclined to one of the main planes, how do i straighten it out again?
In example, i got a plane, subdivided into 16 pieces. All the vertices are not in one plane, beside the two edges. now i want to allign all vertices on the plane to form a flat plane again between the two selected edges, or two selected polygons.
YOU CAN ALIGN THE WIDGET TO THE PLANE BYT CTRL-SHIFTCc
THE YOU SCALE AS PER XY OR Z
I THINK THAT SHOULD DO THE JOB
SALUTATIONS
hmm. That would do the job if i would like to align/scale hundrets of vertices one by one or simply extrude along one plane 
but! There must be something where i just select polygons and with a simple command all others align in the plane of the one i want.
If this feature is really missing i guess i have to write a script for that. Or request one, my python skills are somewhat rusty, despiting the permanent lack of time ^^
Another intresting thing i saw ystd. before falling asleep ^^
I got:
a inclined, but flat plane.
I do:
shft+ctrl+C and set new for the selected plane.
I extrude a new face in the plane of the plane.
I randomly move the 2 last vertices on the end edge in the faces user Z axis
the problem:
now one assumes when i turn on the “face”-user coordinate system, i could move the two vertices back to their place, by simply entering Z=0.
Well when i press “N” i can switch between local and global coordinates.
The first ugly thing is, i cant select the “face”-user system.
The second ugly thing is, if i switch local/global in the properties popup, the coordinates stay the same, no matter if i just switch the system, or deselct and reselct a vertex…
Either i am really too dumb to use this after years, or here are some bugs and missing features.
edit:
must be a lack of sleep. today when i switch global/local the different coordinates show up. but when i change the local coordinates, it seems to affect the global ones… i am confused.
I think this should be possible with the custome transform orientation setting. I can’t really test it at the moment but the idea is to get a custom orientation to be aligned with plane A and then use the Scale to 0 trick to get the points of B to be aligned to A using this new custom orientation.
Details on custom transform orientation can be found here: http://wiki.blender.org/index.php/Manual/Transform_Orientations#Custom_Orientations
Yeah, but the problem with the scale to 0 trick, is it messes up all the geometry.
Lets say those planes A and B are not the only ones.
Good example is a spaceship.
I got nice plain planes. Only in the middle some are off the whole planes Z axis.
When i use the scale0 now, i get them back to the plane yeah, but the geometry is destroyed. then i have to align the view to the top of the plane and restore the topology/geometry.
Also when i got a single polygon made of 2 tris. sometimes it would be great i could just mark the polygon and make it one click planar, instead of tricking around.