Blender Object Default Face Orentation Question

[Paulsian]

Is it possible to change the orentation of a face of an object in blender without creating a uv map and rotating the face giving the appearence that the face orentation has changed but only the map has? 

I'm having problem with an arch i've created some of the faces at the top outside and inside of arch are orentated differently than near by faces. 

As a work around I can assign materials to the problem faces and fix the orentation in sl but would like to know if there's way to select a face in blender rotate the direction of it (not the normal) something like flipping the normal but keeping the normal but rotating it? Is it possible to rotate a normal? I think that's the question :(

[Wulfie Reanimator]

18 minutes ago, Paulsian said:

Is it possible to change the orientation of a face of an object in blender without creating a uv map and rotating the face

For textures to be displayed properly at all, the object needs to have all faces UV mapped. The object you've shown is already fully UV mapped, so this is a good starting point.

To change the orientation of a face, you must select that particular face in the UV Editor and rotate it 90 degrees.

[Paulsian]

Thanks I think my brain is just blah, unwrapping and rotating the faces in the uv map editor will rotate the face. 

It seems like I tried that a bunch of times and it's not sticking when I upload the dae to sl. I'll try again and again. 

Ty

[Paulsian]

Tried that and as long as the texture that has been mapped is uploaded all is fine but without a texture uploaded my model is still face wonky. 

first image is problem area, second image is uvmapping with the problem areas rotated, third image is what the model looks like without the texture mapping applied during upload but has just a random brick texture i added to the model, the forth image is what the model looks like with the texture applied during upload, all is well seems but is not, when the texture is removed and my random brick texture is added the model still has the problem parts im trying to fix in blender. 

I'd like to manually correct the problem in blender and appears the uv map is not changing the model itself but covering up the problem? 

[Paulsian]

I think I need to access and edit the default map and bake it in? 

[Paulsian]

does that make sense I just came up with it.

[Paulsian]

I think in blender correct face attributes is the solution. will have to experiment. 

[Paulsian]

nope  i'll tinker with the normal edit modifier  it's probably not going to work either. I love pressing buttons  I'm like sherlocknoobs. 

[Paulsian]

I think the uvwarp modifier but I don't think it can modify a face. I think i'm getting closer to an answer. Might just have to use a few of my assign materials on the problem areas and fix in sl. I know there's a way. I'll play with uvwarp see way to isolate object may have to detach face warp and reattach... seems tedious. 

[Quarrel Kukulcan]

Check that your object only has one UV map. It's in the Object Data Properties:

 

SL only allows one UV map, but Blender lets you have multiples. If you have more than one UV map and you upload, SL will keep one (I'm not sure which) and throw out the rest. That is one possible reason why your UV edits aren't uploading. If that is the case, figure out which of your UV maps is the right one and remove the rest with the "-" button to the right of the list.

But your problem is a UV mapping issue, and the ideal way to fix it in Blender is to rotate the UV map vertices, not rotate the faces in the mesh.

Don't worry about vertex normals. That's something completely different and can't cause this.

[Aquila Kytori]

13 hours ago, Paulsian said:

I'm having problem with an arch i've created some of the faces at the top outside and inside of arch are orentated differently than near by faces. 

 

When you are dealing with several UV islands like that it can be tedious to get them all aligned correctly in the UV space so that when the seamless brick texture is applied the bricks are all orientated, scaled and aligned correctly with one another.

You could try a slightly different approach, where you only have one UV island to deal with.

At the moment it looks like your archway is composed of 2 (or 3) separate objects, columns and arch. First you would need to join these together so that they are one object in Blender. They can be separated again at the end of the UV unwrapping process.

 

Preparing the Arch before UV unwrapping :

Before joining, in Edit mode delete the top and bottom faces of the columns.

Next, in Object mode select the column(s) and arch objects and join them together so that they are a single object. Ctrl J

In Edit mode, select All and remove any duplicated vertices (where the top of the columns meet the bottom of the arch) M > Merge by Distance.

Select one of the outer edge loops and mark it as a UV seam. See image below.

Next Open the Object Data Properties tab (little green triangle icon) and delete any UV maps that are in the UV Map submenu. (See image below).

Delete any materials  then create a new  "brick" material (a seamless image texture in the Shader Editor) and assign it to your archway:

 

Now we are ready to unwrap. Edit mode, select All > U > Unwrap.

It should unwrap something like in the image below. You should also now have a single UV map in the list if UV maps.

 

The next step is to Straighten out the Uv's. First we need to straight one of the UV quads, then with that selected we can straighten all the rest with a single click.

Choose a quad near the middle of the UV island, then in Edge select mode, select one edge of this quad.  Right Mouse Button open the UV Context Menu and choose the Align X (or Align to Y which ever is appropriate) This will align the edge to the X axis.

Repeat for the other 3 edges.

 

Now the quad should be nicely squared off.

Switch t oface select mode and select the Quad :

 

With the quad still selected hit the A key to select the rest of the UV island. The squared quad is now the active quad.

Open the UV Context Menu  (RMB)  and this time choose the Follow Active Quads option.

 

And now the UV island should be all straighten out :

 

Next is to see how the "brick" material texture looks on the archway.

In the 3D viewport switch to  Material Preview, and in the UV editor load up the seamless brick texture :

 

If the Brick texture happens to be running along the wrong direction you can select the UV island and rotate it 90°.

Now select and scale up the UV island until the scale of the bricks looks approximately OK. You can also move the island around the UV editor to better align the bricks edges to the archway. Note that final scaling and moving can be done when archway has been upload and rezzed inworld.

 

Now that all the UV unwrapping and editing has been done you can, if need be split the archway into smaller parts (objects) again ready for exporting to SL.

To separate: in Edit mode select parts of mesh and hit the P key > Selection.

 

I hope I haven't made this seem too complicated because it isn't really. I just a lot of images to try to explain the method .

T

[Paulsian]

7 hours ago, Quarrel Kukulcan said:

Check that your object only has one UV map. It's in the Object Data Properties:

 

SL only allows one UV map, but Blender lets you have multiples. If you have more than one UV map and you upload, SL will keep one (I'm not sure which) and throw out the rest. That is one possible reason why your UV edits aren't uploading. If that is the case, figure out which of your UV maps is the right one and remove the rest with the "-" button to the right of the list.

But your problem is a UV mapping issue, and the ideal way to fix it in Blender is to rotate the UV map vertices, not rotate the faces in the mesh.

Don't worry about vertex normals. That's something completely different and can't cause this.

thank ill keep eye on this good tips :)

[Paulsian]

7 minutes ago, Aquila Kytori said:

 

When you are dealing with several UV islands like that it can be tedious to get them all aligned correctly in the UV space so that when the seamless brick texture is applied the bricks are all orientated, scaled and aligned correctly with one another.

You could try a slightly different approach, where you only have one UV island to deal with.

At the moment it looks like your archway is composed of 2 (or 3) separate objects, columns and arch. First you would need to join these together so that they are one object in Blender. They can be separated again at the end of the UV unwrapping process.

 

Preparing the Arch before UV unwrapping :

Before joining, in Edit mode delete the top and bottom faces of the columns.

Next, in Object mode select the column(s) and arch objects and join them together so that they are a single object. Ctrl J

In Edit mode, select All and remove any duplicated vertices (where the top of the columns meet the bottom of the arch) M > Merge by Distance.

Select one of the outer edge loops and mark it as a UV seam. See image below.

Next Open the Object Data Properties tab (little green triangle icon) and delete any UV maps that are in the UV Map submenu. (See image below).

Delete any materials  then create a new  "brick" material (a seamless image texture in the Shader Editor) and assign it to your archway:

 

Now we are ready to unwrap. Edit mode, select All > U > Unwrap.

It should unwrap something like in the image below. You should also now have a single UV map in the list if UV maps.

 

The next step is to Straighten out the Uv's. First we need to straight one of the UV quads, then with that selected we can straighten all the rest with a single click.

Choose a quad near the middle of the UV island, then in Edge select mode, select one edge of this quad.  Right Mouse Button open the UV Context Menu and choose the Align X (or Align to Y which ever is appropriate) This will align the edge to the X axis.

Repeat for the other 3 edges.

 

Now the quad should be nicely squared off.

Switch t oface select mode and select the Quad :

 

With the quad still selected hit the A key to select the rest of the UV island. The squared quad is now the active quad.

Open the UV Context Menu  (RMB)  and this time choose the Follow Active Quads option.

 

And now the UV island should be all straighten out :

 

Next is to see how the "brick" material texture looks on the archway.

In the 3D viewport switch to  Material Preview, and in the UV editor load up the seamless brick texture :

 

If the Brick texture happens to be running along the wrong direction you can select the UV island and rotate it 90°.

Now select and scale up the UV island until the scale of the bricks looks approximately OK. You can also move the island around the UV editor to better align the bricks edges to the archway. Note that final scaling and moving can be done when archway has been upload and rezzed inworld.

 

Now that all the UV unwrapping and editing has been done you can, if need be split the archway into smaller parts (objects) again ready for exporting to SL.

To separate: in Edit mode select parts of mesh and hit the P key > Selection.

 

I hope I haven't made this seem too complicated because it isn't really. I just a lot of images to try to explain the method .

T

Thanks so much, I appreciate it very good images and info. I'll do some testing in bit.but yep I joined and merged the verticies for the parts. I think i'm seeing a pattern. I need to delete that default uv map in the properties and then the uv map I create will then be the default and I can then upload to sl without going to the sl uploader tab with texture and check box (in theory). It's a shame can't just edit the default map if that makes sense.

I don't want to have to rely on textures making my model faces appear to behave logically. I'd like to be able to use any texture in sl world on my model look same way as it would if a texture was uv mapped/tweeked and brought in specifically for the model from blender. 

I don't like or understand the way if multiple pieces that are joined how blender creates and objects' default uv island/s. I saw a video about the follow active quads last night and that was really cool and helpful above and beyond tip you shared. 

Thanks again for all your help.

[Paulsian]

Eureka it worked. But I have a slight issue. I love using the sl planar texture option cause it makes all the faces uniform. I was able to get rid of the stinky default blender uv map and create a primitive map just for testing and uploaded model to sl without any extra steps and sl accepted the new default map. The only problem now is when I select the planar option for texturing it seems to revert to the models initial default map? The red arch is before I ditched the blender map and the green is after (sure it's funky but I can see sl took the new default map) the aqua is green model but the sl texture map set to planar. it seems to be behaving like it never had a new default map? 

I can get used to not using planar but I will still know it's funky. 

[Paulsian]

this is great I can work with this. I usually assign materials to as many areas as the sl 8 allows me to. at least even with the sl default mapping I can mix. guess the planar knows I used different shapes to construct the object and is behaving based on the circle and cube. I wish I could tell the circle to behave as a cube in blender when it comes to mapping.

[Wulfie Reanimator]

12 minutes ago, Paulsian said:

I love using the sl planar texture option

@animats may be able to explain a little bit about how planar textures work by now. I vaguely remember him asking about people who use this feature, when he was doing science on planar textures some time ago.

[Paulsian]

I'm dabbling with my arch pieces in blender and top of arch was made from a circle and that object has a default map.

I'm also dealing with cubes and those each have their own default uv maps. 

Wondering if 2 cubes and 1 circle is joined which uv map becomes default, if it's alphabetical they could take on the uv map of the circle. or if they all merge blender might try using some sort of logic. I thought it would take on last object selected uv map but swore I tested that a few times. As it does for object orentation. wondering if I get rid of each of the object except one of the cubes default map will that some how magically push to the circle. 

I started wondering this as I was shaping a plane I created from a cube to make the arch piece as experiment. 

 

[ChinRey]

1 hour ago, Paulsian said:

Eureka it worked. But I have a slight issue. I love using the sl planar texture option cause it makes all the faces uniform.

As Wulfie said, Animats can probably explain the details and so can @Coffee Pancake.

However, one thing that is quote important in this context is that planar mapping completely ignores the object's UV map so there is nothing you can do in Blender to change the end result.

[Paulsian]

1 minute ago, ChinRey said:

As Wulfie said, Animats can probably explain the details and so can @Coffee Pancake.

However, one thing that is quote important in this context is that planar mapping completely ignores the object's UV map so there is nothing you can do in Blender to change the end result.

Thanks that's what im trying to correct. I kind of knew deep down it was not the uv map issue it was issue with how the models's faces were orientated. I'm thinking each shape used in blender has its own face behavior. a circle treats sl planar differently than a cube. a circle is a 2 dimensional object and does not have faces with a circle is extruded it takes on apparently a few different behaviors it might be based on rotational values? 

I'm so sorry for any headaches this has caused. I wish there was a magic button in blender to configure what sl calls planar settings. 

[Paulsian]

I made the arch top from a cube and then with some extruding. I'm getting closer by removing all the uv maps at least face sides have some more logic they are facing the same direction its just some faces are slightly larger than others in planar not consistant. 

I think it's going to be a lot trial and error. I could fix those areas with the uvwarp modified in theory unsure if it correct the planar issue and maybe with correct face attributes enabled during extruding would correct the face scaling issues. Would love a select all and correct face attributes or make them same as this cube or something simple. Nothing is ever simple ever  

 

[Quarrel Kukulcan]

3 hours ago, Paulsian said:

The only problem now is when I select the planar option for texturing it seems to revert to the models initial default map?

The planar option ignores your UV map and tries to figure out how to apply the texture all by itself, as if it were projecting the texture onto the object's surfaces from all 6 axis directions at once. It's unpredictable and mysterious (and also pretty bad at times, including all the prims with curved surfaces).

 

Quote

Wondering if 2 cubes and 1 circle is joined which uv map becomes default

If the UV maps all have the same name, they'll be merged.

If they have different names, Blender will keep them separate. And then you'll have something that won't upload right.

Make sure they have the same names before you merge. Otherwise you'll have to re-separate, rename and re-merge. (Or re-unwrap everything. It's fussy work either way.)

 

[Paulsian]

one of my experiements. i'm determining if by going from bottom to top with nice clean piece of mesh face (fill) and then loop cut a few edges and line those up to the arch will it act right in planar view in sl. to be continued... 

I tested just the flatness and it looks great, honestly I wanted flat pointy arches anyways, but i'm too far into this to turn back now. 

[Paulsian]

hmm hmmhmm hmm progress

[Paulsian]

experiment failed...planar view maybe it's picking up the other crazy sides craziness. Maybe should do it to both sides. 

[Wulfie Reanimator]

1 hour ago, Paulsian said:

experiment failed...planar view maybe it's picking up the other crazy sides craziness. Maybe should do it to both sides. 

This result makes sense if planar projection is done from 6 different directions.

At the top of the arch, the 4 surfaces (2 on each side) are most aligned with the +Z axis and get a texture projected from above.
The next few surfaces of the arch are more aligned with the X or Y axes and get a texture projected from the side.
And of course, the flat side of the arch gets a texture projected from another side.

While you might think that "just rotating the surfaces on top 90 degrees would work," not only have we established that planar mapping can't be adjusted by hand, but even if the top texture was rotated 90 degrees in this case, it would not work as a general solution for all objects.

Edit: I now remember Animats' threads.

https://community.secondlife.com/forums/topic/483690-planar-texture-mapping
https://community.secondlife.com/forums/topic/484154-wanted-mesh-objects-with-planar-mapping
https://community.secondlife.com/forums/topic/486356-sculpts-and-all-that

Particularly that planar mapping is intended for flat surfaces, not curved ones.

Edit 2: I ended up making some mesh models to experiment for myself.

When I uploaded a mesh cylinder with flat shading, it caused each separate surface to get its own texture projection. I can clearly see that the direction changes at 45 degree angles -- exactly between each axis. When I uploaded the same model completely smooth-shaded, the entire object had one massively distorted texture.

The difference between flat shading and smooth shading is that flat shading causes faces to be disconnected from each other, as in the edges between faces are duplicated, and this basically ensures that every flat surface is isolated on its own plane for texture mapping. (Though there are clearly visible scaling issues for faces which are at odd angles from X/Y/Z.) For smooth shading, all faces are connected to each other, causing planar mapping to fail catastrophically because all these different surfaces are trying to fit into the same plane that they aren't in.

TLDR:

Animats was right. Planar mapping only works for surfaces which are completely flat and perfectly aligned with X/Y/Z in object space. Flat surfaces at odd angles will scale wrong. Smooth surfaces will distort completely.

Edited September 10, 2022 by Wulfie Reanimator