Here's a way you could do it.
Duplicate the hallway, select the duplicate, go into edit mode, select this face:
and then press A to select all faces. This is now the active face.
Change your snap settings to Vertex and make sure Active and Move are selected.
Press G and then X or Y depending on how the hallway is aligned, then either press CTRL if ...
If I'm understanding your question correctly, the issue is that you are in Solid view and want to see the Material Preview.
Click this button at the top right of the 3D viewport and you will see the material attached to the object.
As an aside, you can change the color of objects in Solid shading mode by scrolling down towards the bottom of the Material ...
This is rather easy to do.
Just add a Simple Deform Modifier.
Set it to Bend and select the right axis.
Enter the desired angle (it's 45° by default)
In this case bending along the Z axis doesn't work as expected.
To make it work, rotate the object's origin by -90°, or use an empty rotated by -90°.
Thanks to @lemon, @plem and @robin-betts for ...
For two triangles can use the rotation difference of the hinge edges adjoining face normals. In angle axis format this will be the angle required to rotate, and axis should be parallel to the hinge edge.
To use, edit mode, edge selection.
Select hinge edge.
Shift select edge on tri face you wish to rotate to
Hit run script.
To Rotate the vertex into the plane, follow @Lemon's answer, or a variant.
To Project the vertex onto the plane:
With pivot set to 'Active Element'
Create a Custom Orientation from the face/ 3 vertices which will remain stationary.
This is the '+' in the Orientation dropdown. You may want to add this to your Quick Menu, or create a shortcut for it. You ...
I think the answer is: yes you can.
Select the connecting edge and snap the 3D cursor to it
Set the pivot point to 3D Cursor
The connecting edge still selected, add a custom transformation orientation and keep it as orientation
Select the first triangle (the target)
Use ShiftNumpad 1 or ShiftNumpad 3 to be in orthographic view aligned with this ...
The answer is: You can't.
But you can trick Blender to do so:
Let's say we have two triangle faces in random locations. They are part of one object:
What we can do to align the faces is this:
1) Since we cannot automatically align the faces in edit mode, we will select one face, and P to separate it into another object, and transform origin to geometry:
It is impossible to exactly reduce the amount of faces of an object, but there are tricks to doing so:
1) Use the decimate modifier, and adjust the settings while watching the faces-count and the quality of the object.
Here's how this works: Go to the modifiers tab, and select decimate. Then set this modifier to un-subdivide. The modifier will show the ...
As already mentioned in other answers you can't edit object parameters after they are created in Blender. After the creation process they become regular mesh objects and loose any "parametric properties" they had.
In an attempt to not leave you empty handed I'll try to present an alternative solution: Be smart, use available tools to your advantage.
It was caused by one flipped face.
The Bevel tool was confused, not knowing which way to go.
Recalculate Normals, so they're all pointing outwards.
Then the Bevel tool will work correctly.
Mesh > Normals > Recalculate Outside
You can do this by using Blender's knife tool. In edit mode, select the knife tool, and LMB to start. Then drag the line to the opposite corner of the cube. LMB again, and then press 'enter'. You have a new diagonal line now on the cube.
So, First, you have overlapping vertices.
Select all your vertices with A in edit mode and vertex select mode, and Press ALT + M > by distance in order to eliminate double-vertices.
The real problem is you have 3 inside faces which mess up your boolean operation. Notice how in wireframe view, some faces have a clearer shade of grey. That means there ...
Most likely you have overlapping vertices. That means two or more vertices share the exact same position in 3D space. When you click on one of them, you are actually selecting a vertex, but it doesn't appear like it since one or more are overlapping.
Select all the vertices with the shortcut A (in edit mode) then right click > Merge vertices > By distance....
A few things wrong with this: 1) you are selecting vertices, not faces. This would be so much easier to do by selecting faces. 2) You are trying to scale the face along the X axis. Since it can not get thicker along that axis, to move it, transform it on the X axis, don't scale it.
Select the vertices/edges/faces you don't want to be affected by proportional editing and hit H to hide them, when you're done with the proportional edit, unhide with Alt + H .
You have now done a proportional editing that did not affect the hidden vertices/edges/faces.
Recorded a quick video showing how to easily do it.
The steps are:
Create two loop-cuts on the smallest/thinnest part.
Snap the new loops along the X axis(or whatever axis are appropriate for your mesh) to the mesh you want to merge it with.
Select the faces your mesh is going through and create an inset face.
Scale down the new faces and snap the edges ...
this is a simple topology, just add there a few more edges and merge the vertices. You can use voxel remesh as that is just one click operation but it makes the next modeling impossible in a classic way.