Creating Surface textures for sculpties with blender
abstract: Welcome to our secnd blender tutorial. We will now create a surface texture for a sculpted prim helmet. If you want to get more basic informations about how we created this helmet, please go and fetch the video about “creating sculpted prims with blender” . Then come back here. And don’t miss the new companion video “Texturizing sculpties with multiple images” which shows a blender only solution ( our preferred method)
Watch the video here:
Or read the text:
Although you can create your textures entirely in blender, we have choosen to use an external paint program. In this tutorial we will use paintshop. Of course you also can use photoshop, or any other image editor, the process does not depend on this.
A little explanation of UV-textures
So lets go back to blender now. It is important to know, that the whole process is controlled by a UV-texture, which operates mostly in the background. The UV-texture is explicitly used for 2 separate tasks.
- first, it is used to create the sculptie-map itself. This task is very well supported by the scripts of Domino Marama We have explained the process in our first tutorial.
- second, the UV-texture defines the mapping between plain texture files, and the object surface. We will take care of this mapping now.
You find the UV-texture in the mesh tab. Its name is “UV-tex”
The UV-map is always a perfect square, containing 1024 smaller squares. Each of these squares is mapped to a different part of the surface texture. For second-life this mapping can not be changed. So, when you understand the mapping, you can create your surface texture by hand. But this is not a good idea, because the transformation looks a bit strange.
Take a look at the final result of this tutorial. Imagine you would have to create this texture manually ? oh! That would not be easy, don’t you think?
A practical approach
So the question is, how can we map a plain 2D image of the helmet, into a usefull sculptie texture! The solution is: We will create a second, very different
UV map. This map directly projects the 2D image on the object. Then we transform that projection map into the final second life compatible map. The good news is: blender can do this transformation for you.
- Ok! First step: Create a second UV-texture. Just click on UV-texture, new. A new UV-texture is now available. rename it to: “surface-texture”. And then click on the button, which is located directly left to the input field: “rendering, UV texture”… hey! This was easy!
- Now create a new image, and set width and height to 1024 each. Use the middle mouse button to scale the image down.
- Now we need to ensure, that multi-res is disabled. Otherwise the following steps will not work as shown here. Search for the multires tab and click on: “apply multires”.
- Please also select, “occlude background geometry”, so that you only select visible parts of the object.
- Then switch to face select mode. Believe me, in the next few steps, selecting faces works better , compared to selecting vertices.
Creating the initial texture
Now, back in the 3D window, click “mesh -> UV unwrap -> project from view”. This is the step, where you define the projection of your 2D image to the object surface. Hence, now you see a projection of the helmet on the right window. but when you look closer, you see that the vertices are now displayed on top of each other. We have to separate the left and the right side and the inner part of the helmet. We do this by selecting only subsets of the vertices time by time. Then we will rearrange the map by hand. Don’t worry, it is easy.
Separate the sides
- So, let us deselect all vertices first. hint: press, “a”, again. Go to the front view and select the now visible side of the helmet. go also to the top view. You probably have not selected all vertices of this side. Do this now.
- We have now selected one side of the helmet. Go to the UV-editor, select all vertices here, and move them down. Be sure, that you have disabled multi-res as explained before. ok! It is time to also select the other side of the helmet. You can do this from the top view.
- Now, take care! in the UV editor click on UV, then check, that “proportional editing” is disabled. If this is not the case, your mesh will suffer from heavy distortions.
- Still in the UV editor, de-select all vertices, then select the new side, and move it upwards.
- Now back to the 3D window. Here select the first inner side of the helmet.
- Go back to the UV editor and move the new mesh points out of the way.
- Finally select all mesh points in the 3D window. Do this by pressing, “a”, twice.
Now arrange the UV texture as you like. Take care that you fill as much space as possible. That will increase the quality of your final texture.
This UV-texture looks quite simple. It can be filled with content without adding too much of extra work. We will save this image now as a template. In the UV-editor, click on UV, then scripts, save UV face layout.
Now it is time to go to your image editor and create the initial texture. The following clip has been created with paint-shop. Of course you also can use any other editor of your own choice.
After creating the initial texture
Creating the texture, was easy. We did not make any further pixel adjustments. We only applied the correct scaling and moved the image to the correct position.
We have no photo material of the inner part of the helmet. For this demonstration we only colorized it reasonably, without taking care of the details.
But the texture we just created is not yet our final result. We need to get back to blender. Let’s load the just created texture now.
Preparing the transformation
- Check that we are in textured mode, Then we can see how the helmet will look alike at the end of the process.
- And now lets take the final step. We will create a material.
- Go to the material pannel.
- In the tab, “links and pipeline”, add a new material.
- Now go to the texture-pannel. and then add a new texture. Use the texture type “image” here.
- Now load the texture from file. Here we load the texture from the file system. Note, that we also can select it from the combo box, left to the load button.
- Now go back to the material pannel. Then click on: “Map input”. This is the moment where we connect the 2 UV textures. Now click on the UV button. This tells blender to use the UV coordinates as texture coordinates. And finally type in the name of the texture you want to use as input. Remember, this is the name of our surface texture.
go to the edit-pannel and switch the original UV tex back to active and rendering UV texture.
Now create a new image, use 1024 pixels for width and height.
And then bake the texture: Go to Render -> bake render meshes -> texture only.
artefacts from precision problems ?
Sometimes the transformation creates a set of black triangles at the top or at the bottom of the image. If this happens with your texture, then go to edit mode, click on smooth (once). Then, bake the texture again. Now the black triangles should be gone. We believe that this is a problem with mathematical precision at the poles of the object.
NOTE: This problem only happens, when the pole vertices have been collapsed all together. In that case the border faces are triangles, instead of rectangle. But the texturizing algorythm seems to expect rectanlges. When smoothing, the vertex collapse is partially reverted, so that now all vertices are laying on a small ring around the pole. And now, all tirangles have been replaced by rectangles at the border. Now the face calculation can be performed as expected and the black triangles are gone away.
Ok! We are finished now. Save the surface texture to your hard drive. And it is time to go to secnd-life and see your textured sculpty in action…!
In our next tutorial, we will show you, how to work with multiple textures. And finally we will explain how to use the embedded tools for texture creation.
Stay tuned until the next time!
May 23, 2008 at 12:27 am
Fabulous! I couldn’t find this anywhere and I was struggling to work out how to do it from the blender manuals etc. Being a blender noob I was struggling badly. You guys are my heroes! From this tute I managed to upload a texture that fitted my sculptie perfectly. Thank you so much.
May 27, 2008 at 12:03 pm
Thanks a lot for this great tutorial!
Alas - with the new Blender-Version 2.46, the «UV Face select» Option disappeared - and I can’t get my head around on how to achieve the same result as with blender 2.45… maybe I’m just a little stoopid, but I’m a total noob when it comes to 3D and especially blender…
But still - thanks a lot for the work!
May 27, 2008 at 12:45 pm
Hi, Haruki Watanabe;
(we have planned this anyways, but i don’t know, when this actually will happen)
As far as i know, the entire process of texturing does not change much in blender-2.46. I think, you basically just replace all switches to the UV-Face select mode by switching to edit mode (if you are not allready there), but there are some subtle changes. So it looks like we will have to remake this video for blender 2.46
May 27, 2008 at 2:30 pm
Hello, Haruki;
I just have updated the text version of this tutorial for usage with blender 2.46 In fact i only found one major deviation from version 2.45. Basically Hussayn is right, just replace “go to UV Face select mode” by “go to edit mode” and everything else should work as before.
May 27, 2008 at 3:05 pm
Wow, you guys are quick!
Thanks a lot for the changes - I’ll try them right away!
May 27, 2008 at 3:51 pm
Hi again, Gaia & Hussayn,
I tried it and it worked like a charm. The mistake I made, when I first tried it with blender 2.46, was that I still had the «select vertices»-tool selected instead of using «select faces» (the triangle).
However - the black triangles are still there, when I bake the texture. There must be some difference in your workflow than in mine - but we’ll figure that one out too…
Thanks again for your help & the great tutorials!
May 27, 2008 at 11:48 pm
Haruki,
We believe, that the main problem with the black triangles comes from the
fact, that the pole vertices are squeezed to one location. This leads to triangle shaped faces besides the poles. But since the baking tool only works with squared faces, there seems to be a precision problem now at the poles, which lead to black triangles, in fact it leads to faces, which are not getting textured, because the algorythm “forgets” to take care of them.
You can avoid the black triangles very easy:
select the poles of the sphere, then click once on “smooth”
in the edit panel. This lets the pole vertices move a bit away from each
other. In fact this creates a little hole at the poles, but this hole will be closed again automatically in SL. The net effect is, that near the poles we now have again only square faces and not triangle faces as before. Now the algorythm has only to deal with square faces and things run smooth.
I thought, in blender 2.46 the problem has been solved somehow under the hood, but now i realize, that my helmet has got this tiny almost invisible little hole at the top in blender (and no hole in SL), hence that convinces me, that i am right
Good luck
May 28, 2008 at 7:30 am
Gaia,
Thanks a lot for this hint - gonna give it a try as soon as I can
June 8, 2008 at 6:43 am
[...] Blender! Here’s a tutorial on how to do exactly that, complete with a video narrated by synthesized voices! Creating Surface textures for sculpties with blender machinimatrix [...]
June 23, 2008 at 12:07 am
I followed the guide seemingly to the tee, however after I use the script for UV face layout and open the file in Photoshop, all I get is a grid without my image. I must be missing a step. Have you seen this before?
June 23, 2008 at 12:38 am
I have been investigating your problem for a while, but i cant reproduce it. So something very obvious and overlookable must go wrong… Can you provide a .blend file which shows your problem ? Maybe it is best to attach it to the SL forum thread at http://forums.secondlife.com/showthread.php?t=203571 then me or someone else can take a look at it and maybe we can see the problem …
June 28, 2008 at 9:41 pm
I think the problem might be with the multirez button. I have noticed when I select and deselect my images come out in photoshop. Not sure if thats just me but maybe if you are trying to figure it out, it may be a lead.
My new problem is after creating a UV map for my sculpties, by using UV unwrap>project from view>etc for all faces, I save the resulting image, open it in Photoshop, and add texture. No problem everything works fine.
Now I load this file back into blender. I go thru all the steps to set up the image so I can get a useable image when I upload to SL. But when I go to Render>Bake render meshes>texture only, the image I created dissappears and everything goes pink on my image.
IN fact when I set my custom texture as active UV texture before rendering it goes all pink then too, unlike in the video where the image remains. Any ideas?
July 9, 2008 at 12:23 am
[...] can be setup in an easy and reproducible way. We highly recommend to view the tutorial about surface textures for sculpties with blender, before you continue [...]
July 11, 2008 at 3:41 pm
Hi,
Thanks for these great tutorials. However I am stuck on one step. I have no idea how to rotate the maps as shown in the video in the UV / image editor window. Could you help please?
July 30, 2008 at 6:23 pm
I tried this tutorial and I get all the way to the end and I go to Render > Bake Render Meshes > Texture Only and it tells me Error: No image found. What am I doing wrong? Everything is fine (as far as I’m aware) up until this point.
August 10, 2008 at 10:13 am
Hi, London;
Sorry for the delay (we have just been back from holidays here).
Your problem occurs, when you did not select all vertices right before baking. Or something is wrong with your UV maps. ? e.g. the “sculptie” UVmap has been removed or emptied. For some reason once in a while, i encounter such effects too. I never could reproduce it and always suspected, that i was doing something wrong…
So my advice is a bit dumb: Just try it again and take care, that you have selected all vertices before you bake. And ensure, that the UV maps are always available. If nothing helps, send me your .blend file I will then investigate, what causes your problem.
August 24, 2008 at 7:10 am
Hi Gaia,
I tried again many times but failed each time. I did figure out an easier way (for me at least) that doesn’t involve the very scary UV unwrapping. When my sculpts became more complicated or weirdly shaped, unwrapping the UV to make a template became very difficult. If you bake the shadows you can use the shadows as a template and your sculptie texture will end up with some nice shading.
September 1, 2008 at 6:25 pm
I’m having the same problem as London is having. I followed all the steps carefully and get the message “No images found to bake to”. I’ve tried a few times, just can’t figure out where I go wrong.
September 1, 2008 at 7:13 pm
Aenea, i have no idea, what could go wrong in your case. But … can you send me a .blend file in which your problem occurs ? Just go through all steps until you reach the problem. Then package the images (soimewhere in the UV-image editor), save your work and then send me the .blend file
I can then take a look at it and try to understand, what’s going wrong.
you can send the file to gaia.clary@machinimatrix.org
September 20, 2008 at 5:57 pm
Ty for the great tutorials but I am having the same issue as Quincy is having, I load to adobe and it jus shows as a grid also when i hit the new UV button a new layer never appears and I have watched this tutorial least 20 times now.. ty
October 8, 2008 at 11:08 pm
Hello, Great tutorials! Thanks a lot! Is it possible to know the result of your investigaton on the problem “No images found to bake to”, which a few persons (and me…) had?
Thank you
October 9, 2008 at 8:01 pm
Thanks for the tutorials, they are helpful! Question/Problem. I created a cactus sculptie and was finishing by baking a texture (import into SL had zero problems). I used GIMP to create the texture against the UV Face Map. Imported back to blender and all seemed fine. The baked texture seemed to come out “stretched”. Question - if the UV Faces are long or unproportioned to the others, will the texture appear stretched? Also, in comparison, the Faces that were forward in the Face Image Map were textured properly, the curves came out “streched” yet these faces were the same symetry (sp) (Unwraped the cactus had two sides, like the helmut) Should sculpties with curves have more “frontal” faces in the UV Face Map for texture purposes? (I hope I’m making sense LOL) Thanks! - Copper
October 31, 2008 at 3:45 am
First of all, thanks for the great tutorial. I have been trying to crack this for a while but had missed a couple of steps.
I was able to successfully texture a few shapes, and since I make furniture, I was applying fabric textures to basic shapes, nothing complicated.
But I have been having trouble with a couple of things.
The texture on the pole ends of the sculpt still show the effects of pole pinching. I thought at first it was because I didn’t have the UV layout exactly in synch with the vertices, so I took a screenshot of the edit window and imported that into the UV editor window. Even after very carefully lining up the points the texture is still distorted when applied to the sculpt.
Funny thing is, it seems fine when I preview it in Sculpty Space, but once I bring it into SL, the poles are puckered and there is significant blurring around the join (which is a rounded edge). I have tried the sculpt texture at 64, 128, 256 & even 1024 (same as the texture), but it doesn’t seem to make any difference.
I am also getting some minor blurring across the other parts, the flat bits, but that is only minor.
Most of the shapes I am using are based on a rounded off cube, or a wedge with rounded corners, so it shouldn’t be the shape causing the problem. Actually the first thing I tried this did have some fairly complicated geometry so I just out the problem down to that.
Up till now I have been able to hide this by building items with the poles hidden by other parts, but I really need to find out what is causing this.
Thanks for all the great work.