Using UV map in material editor

[SavageDogg]

Sorry about that delay but I figured it out soon after I posted and just simply forgot I asked the question but I am still having problem with getting an Alpha channel into the editor from GIMP if anyone can help me with that. I can only assume I am not adding the alpha channel correctly in GIMP

[SavageDogg]

Here is what I got some time back when I tried to create an Alpha channel in GIMP:



Notice the blue-green... I know that an Alpha channel is possible, Odedge pointed this out for me and plus I managed to successfully get an alpha channel into the Editor but can't seem to replicate it and don't have the original GIMP file to look at.
Here is what I am looking at now:

Again a blue green where the alpha should be...

Please help, this is becoming too aggrivating and I fear I may just kill someone if I don't figure this out. Thanks for everything guys... and gals.

[SavageDogg]

Okay, lets say you modeled a simple wall like so:

You marked all your seams and unwrapped your UV map like the following image:

I saved mine as a targa 512 by 512 and it doesn't much matter, it only determines the quality of the image.
Now lets assume I want the following texture to be applied to the previous UV map:

This image just happens to be 2560 by 1920 pixels. What Blender will do along with most other programs I am aware of, will scale the UV map to fit the image and apply it like so:

So you can see how adjusting the image will effect the finished product... What happens is the program uses every vertice to map the image, where every line intersects. In the case it worked fine because all the lines or edges are parallel due to the object being mostly flat but on something more round you would have to paint a custom texture.


A more detailed model with Islands would more than likely need its own texture painted on top of the UV map but just remember that the UV map will scale on Z and Y to fit whatever texture but the quality may change and distortion may be a problem if you don't scale and allign the images properly(notice the tops and sides of the wall)... The good news is you can move vertices around within the image editor within blender to fit things correctly... Awesome huh?

Okay, Alpha please? lol...

[SavageDogg]

let me see what it is you're trying to do and I could perhaps help more. You can modify your UV in Blenders image editor and also use pinning but make sure you pin every island or you will get a mess. you can also rotate and scale your UV map within Blenders image editor. Just wanted to add that. So just use the basic 'unwrap' and load your image and modify the UV until you get what you like. Basicly don't worry about scaling image, scale the UV. It is much easier.

[Odedge]

A more detailed model with Islands would more than likely need its own texture painted on top of the UV map but just remember that the UV map will scale on Z and Y to fit whatever texture but the quality may change and distortion may be a problem if you don't scale and allign the images properly(notice the tops and sides of the wall)... The good news is you can move vertices around within the image editor within blender to fit things correctly... Awesome huh?

This is basically what I want to do and I know it can be done, but the "how" is beyond me. I found out yesterday how I can visually see my texture on the mesh while in blender, so that's a good thing.

Okay, Alpha please? lol...

Do you have any of the source pictures? Where did you get that chain link fence? I am always up to either learning new things in GIMP or practicing what I already know.

Basicly don't worry about scaling image, scale the UV. It is much easier.

I don't want to try and scale the texture, because I want to use stock ones. Granted, I can duplicate them and scale them, but that would add to to the map's file size.

I would like to learn how to scale the UV. Right now I can make one, but that's about it. If and when I learn this, I think my "essential" blender to unreal process will be complete and can then start learning how to make nicer looking models.

[vonnis]

i dont know about Blender, but in Maya you can UVmap different ways.
you can select the faces and choose "planar mapping" with the option
"camera view" you then get the faces you selected (separately from the rest of the uv coordinates) in the UVeditor.
now you can scale rotate and align those uv's the way you want.

as i see it, you now made a automated uv map. i dont know about blender but in maya you could map the uv's of your choice a second time (as i described above)
or you could cut the vertices of the uv's in the uveditor until you get a seperated uvmaps.


and about the alpha-channel, i dont know, im basicly stuck with the same, i edited my normals in maya but it seems that UnrealEditor doesnt care about that, and that you need to make a separated image wich defines the normals,

[Odedge]

you can select the faces and choose "planar mapping" with the option
"camera view" you then get the faces you selected (separately from the rest of the uv coordinates) in the UVeditor.
now you can scale rotate and align those uv's the way you want.

That's what I am looking for in Blender. Something similar to the Surface Properties options for brushes. Since I will be starting out with base materials, I don't need to manipulate it much.

[SavageDogg]

I think I understand now. So you want to know how to use the image editor to manipulate the UV map within Blender before export so you can use a stock texture in UT3?

If so, split your screen and go to your display current window type button in the lower left hand corner and scroll up to image editor. press 'A' to select all your model with seams in place and hit 'U' and unwrap. it should show your UV map in the image editor. Capture your texture for the purpose of lining up your image, and load it in the image editor. Now you can manipulate the UV the same way you would your mesh in the 3D window.

[Odedge]

I think I understand now. So you want to know how to use the image editor to manipulate the UV map within Blender before export so you can use a stock texture in UT3?

If so, split your screen and go to your display current window type button in the lower left hand corner and scroll up to image editor. press 'A' to select all your model with seams in place and hit 'U' and unwrap. it should show your UV map in the image editor. Capture your texture for the purpose of lining up your image, and load it in the image editor.

Yes, this is what I want to do and can do this in a basic sense.

[quote[Now you can manipulate the UV the same way you would your mesh in the 3D window.[/QUOTE]

This is the "hard" part. I can start moving stuff around, but I don't know what I am doing. Is there any tuts that explain this in detail?

[Hazel.H]

Here is what I got some time back when I tried to create an Alpha channel in GIMP:

Ouch.... what are all those purple squares, and why is it blue? Alpha channels need to be greyscale (black for full 0% opacity, white for 100% opacity). Usually the alpha is placed in the alpha channel of the TGA image, you can also generate alpha channels in the material editor, as long as it is greyscale.

In Photoshop making an alpha channel is as simple as selecting the channel from the list at the right, then pasting a greyscale image into it. I'm not sure how it's done in GIMP.

See all those pins on the side of the Texture Sample node? Each one represents a channel in the image - All channels (black), Red, Green, Blue and Alpha (white). Once you have a new image with an alpha channel, plug the alpha pin into Opacity, and change the texture properties at the bottom to translucent and unlit. With the fence, Masked is would be better as it doesn't have to be unlit and uses 0 or 1 values for alpha.

With this texture you could plug the blue channel into Opacity just to see what happens, but I would recommend putting the alpha into the alpha channel of a diffuse texture in future

[SavageDogg]

Plannar mapping I think, if I understand correctly, is blenders 'Project from view' equivalent but I don't think that will help you.

Yes, this is what I want to do and can do this in a basic sense.

[quote[Now you can manipulate the UV the same way you would your mesh in the 3D window.

This is the "hard" part. I can start moving stuff around, but I don't know what I am doing. Is there any tuts that explain this in detail?

Not many. Their is only one that I can think of at this moment and that is grey beards UVTut video tutorial. Other than that, I would really need to see what it is you're doing to really help.

[SavageDogg]

That is what I don't understand ' Why is it Blue?' It is not suppose to be blue at all, it should be black or transparent but it looks as if it is making the red channel transparent and leaving blue and green... What the heck? Within GIMP it looks fine. The areas between the chain link is transparent but when I open it in the editor or any other program, it looks like what you see there.

[SavageDogg]

You know something? After writing that last post, I think I know what I am doing wrong and it is in GIMP... Hmmm, let me give something a shot...

... Nope, didn't work. Still got the same blue-green **** going on...