In this tutorial you will learn how to create a shadow map on your sculpties that you can use to create high-quality textures for your sculpts.
Texturing with Shadow Maps
For some sculpties, slapping on a tileable texture from your inventory might work well enough.
Often, however, it looks better if you create a texture specifically for your sculptie. Sometimes this is even necessary to get the look that you want. The trouble is, how do you make a texture that fits your sculptie exactly?
I’ve often seen people use a colored and numbered grid to map out the general location of certain parts of a sculptie, then match it to the same grid in 2D format. While this method has its place, it can get pretty tedious.
There are features in Blender that will help us make textures for our sculpties relatively quickly. In this tutorial we’re going to focus on baking ambient shadows, which is probably the fastest and easiest to understand method available in Blender.
In this tutorial, I ask that you have your screen split in half and one half switched to the UV/Image Editor.
Ambient Occlusion
Before we begin, I want to change the draw type in the 3D View to Textured. Find the small menu to the right of the Mode menu (marked in red – click the image to enlarge) and switch the draw type to Textured. If your sculptie is currently assigned a UV texture (such as a sculpt map), you’ll see that texture placed onto your mesh in the 3D View.
If you’ve ever worked with other Blender sculptie templates, you may already know how to bake textures onto an image. However there are other types of images we can bake. The type we’re going to bake now is Ambient Occlusion – or global shadows.
First we want to assign our mesh to a new texture. If you have multires on your mesh, you need to switch to Level 1 or Apply Multires before you change textures. Then go into edit mode and select All, by tapping A until all the vertices are yellow and the faces pink. Then in the UV/Image Editor, go to the menu Image > New. Make a new image that’s 256 x 256 or 512 x 512. Hit OK. (If you switched to Multires level 1, you can now switch back to level 3.)
Now go to the Scene > Render Buttons (marked in green – click the image to enlarge) and then find the Bake tab (blue) and change the bake type to “Ambient Occlusion” (yellow) and hit Bake. Wait a few moments for Blender to bake shadows onto your image. Save the image as something meaningful.
Usually this shadow map gives you enough ‘landmarks’ on the texture to be able to paint a texture that exactly fits your sculptie. Just use your favorite image editing software.
Previewing Your Texture
Testing your texture before uploading is incredibly easy. Simply save your new texture right over the file you saved from Blender. Then in Blender, reload the texture file by selecting Image > Reload in the UV/Image Editor.
Your new texture will now be wrapped around your mesh. If something’s wrong, but you’re not sure where it is on the image, you can select the faces on your mesh and it will highlight them in the UV/Image Editor.
Another Texture
Maybe you’d rather keep the original shadow map or maybe you have multiple texture that you want to preview, like if you’re doing multiple recolors. You save these textures separately and then open them in Blender to preview on your mesh. Go to Image > Open. Find the texture you want and hit “Open Image.”
Then in Edit Mode swith to Multires level 1, select all your vertices, and find the drop-down menu next to the UVs Menu (marked in yellow). Click the small button with the arrows and select your new image. From this menu, you can also switch back to your old image, or to any image currently opened in Blender.
Multi-Sculpt Bake
If you have more than one sculpt mesh in a single .blend file (see how here) then each mesh may effect the shadow baking of the others.
If you look at the image to the left (click to enlarge) you can see how the smaller mesh has created a dark shadow on the larger one.
Sometimes this is desirable, such as when you want a drop-shadow look on your group of sculpts, but if you’d rather they affect each other less or not at all, move the meshes away from each other before baking.
Good! but i have a question : how do i calculate my texture (i.e the leather of my hat) and the Ambient occlusion image baked into one image?
I have the leather in one hand, the AO one the other, but is ther a way to make it one in blender?
Thanks a lot for your answer)
Uhh. I’m sure there’s a way to do that with Blender’s textures and materials, but I’ve never really done it, as I prefer to do my texture work in Photoshop.
So I’d have to look up information on it before I’d be able to tell you anything.
It’s possible to feed in two or more texture sources, merging them. This can be a colour texture and a shadow map. If you have used simple UV Texture mapping, and haven’t got different UV maps for your leather and AO shading, this is “reasonably” simple. But it probably won’t seem that way the first time you try it. The instructions here are for 2.49.
First save both your textures to the hard drive, say leather.tga and ao.tga.
Now you need to create a material: shading/material buttons (F5), Links and Pipeline, Add New. Rename the Material something sensible. This will create a material and a material index (a mesh material slot number), assign the material to the index, and assign all faces to the index. All by pressing Add New. In short this means what you do next will apply to the entire sculpty.
Next you need to add two textures to the material.
To do the first, go to the texture buttons (F6), and in the Texture panel Add New. Rename it leather_texture. You will see it appear at the top of the texture stack, a column of 10 or so slots. Now in Texture Type select Image. Two more panels will appear. In the Image Panel, use the selector to pick leather.tga, associating your leather image with the leather texture.
Now do the second: click on the second slot in the texture stack under leather_tetxure, Add New and rename it ao_texture. Set Texture Type to image, and associate the texture to ao.tga using the selector in the image panel as before.
Now back to the shading/material buttons (F5). You will also see another view of the texture panel here, with the texture stack showing the two textures. Leather at the top, AO underneath. (The order is important, and the two chevrons to the right will let you reorder them.)
Select the leather_tetxure in the stack. Go to the Map Input and select UV. This will give the base texture.
Go back to the texture stack tab, click on ao_texture. Go to the map input tab and select UV. This will render on top of leather.tga as blender works its way down the stack. But you don’t want to override leather.tga completely, so now go to the Map To tab. Chage “Mix” to “Multiply”, using the texture blending mode selector, and move the Col slider below that selector to say 0.4. The higher the number, the greater the effect of the shading. You need to experiment to get the right number.
Okay final step. back to the 3D viewport, and into edit mode. Select all vertices. In the UV/Image window, create a new image of the final size you want to export into SL, probably somewhere between 256×256 and 1024×1024. In the Render menu, Bake Render Meshes – Texture Only.
This should create your combined leather/ao image. Save it to hard drive.
Hm, I can’t get this to quite work.. even with a sphere the difference in the light/dark grey colours is very slight and also it looks sort of grainy/speckled.
I’m guessing it has something to do with my global light settings or something..any ideas?
Sorry I didn’t reply sooner. I somehow missed your comment. The ambient light of an object isn’t determined by any light source, but rather by the mesh casting shadows on itself. So if you have a mesh with a lot of hills and valleys (or wrinkles and creases) then the valleys will be darker because of the hills block the ambient light.
For something like a perfect sphere, no part of the mesh is blocking ambient light, so you won’t get any shadows. If you wanted a shadow on the sphere then you would need to create another object and place it close to the sphere in order to block the ambient light.
I am having the same issue as Rowan. I attempted several different sculpts, following your directions as closely as I could interpret, but when I try to bake an ambient occlusion map, my texture comes out grainy, without any notice of visual landmarking that I can tell. Just speckled grey and white. I plan to take these maps into Photoshop when I’m able to texture them accurately if it makes any difference in finding a resolution.
Any ideas as how to fix this?
Hey, I just replied to Rowan so maybe that will answer your questions. Just know that ambient light has to be blocked by faces of a mesh in order to create shadows. A mesh with deeper or sharper wrinkles and creases will have darker, more defined ambient shadows.
Meshes that are very smooth may not have any ambient shadows at all. In order to get shadows on smooth meshes, you need to use other objects to force the shadows on.
go to materials panel, in there find the world panel then Amb. oclussion tab, in there find Samples and increase the number of samples (the higher it is, the more time will take to bake the texture) that way it wont be so grainy.
I did not understand this. the part of making a New. Texture i get a black screen and when i do the Bake thing nothing changes. Maybe i’m doing something wrong but i wont get the shadows to be put on a texture which i can them export to my pc and edit in photoshop.
It sounds like your new image isn’t getting assigned to the mesh properly. Make sure when you assign to the new image that you A) are in edit mode with all vertices selected and B) switch to multires level 1.
I dont understand how to switch to multires level 1
Find the Tab labeled “Multires” in the Edit buttons and switch the Level to 1. If you’re having trouble finding the multires tab, try doing a Google search.
Also keep in mind that I’m still using Blender 2.49. If you’re using Blender 2.5 or higher, then I can’t help you much with the interface.
How do i add texture to a sculpty? specifically fashion sculpties such as collars, bottom of pants, sleeves, etc. What do I do with the shadow maps? Please if you can explain to me. I am using gimp for my designs. I have to add these sculpties to my stuff to make it look better. I am at a roadblock right now. I have purchased some full perm sculpties from xstreetsl.
Wonderful tutorial! Thank you so much for this resource!
HI and thank you for your excellent tutorial, which has single-handedly helped me overcome my frustration with sculpts for SL.
I have a problem though, with the ambient occlusion:
When I copy an item ( say, a sleeve), mirror it to go on the other arm, do some finalising sculpting… my lovely sleeve is ready. However, when I try to bake an ambient occlusion on this mirrored object, it comes out near black, there is a little bit of grey but it seems like the whole thing is inside out (i.e. parts that should be light, are dark, and vice-versa). Which makes sense considering it is a mirrored object. Is there a way to get the ambient occlusion to work properly in this case? Thanks in advance. Best wishes, Aeris
the way around it… to Mirror the mesh to x local. It brings up the object inside out, but it renders the ao map correctly,. Plus, it renders the sculptmap properly (not inside out, either). Double Win!
Hey Murgy,
I did want to thank you again for your work on this fantastic tutorial. I have since had more success with Blender following your guide, but I’ve hit another snag. I’ve made a quick Booney Hat to showcase the error I’m getting, for some reason the base of the hat itself renders Ambient Shadows perfectly. How ever, the small embossed band does not render anything at all. I’ve bound the new image as correctly as I can tell, (making it in Edit Mode with all of the vertices selected and applied multier) but for some reason, when I go to bake the image, it calculates for a while (like it would normally if it was actually writing shadows) and turns the entire image black. It does not make any sense. The base sculpt renders in the cast shadow of the object, but it refuses to bake the objects shadow itself.
Any ideas?
http://imageshack.us/photo/my-images/163/78373174.jpg/
If its not giving you any sort of error it could be that the mesh somehow got turned inside-out. Easiest way to tell with sculpties is to import the sculpt into SL and see if the sculpt looks inside-out in world.
But you can also just turn the mesh inside-out again and see if that fixes the problem. For a symmetrical mesh like this, you can do it by going into Edit Mode, selecting all your vertices, then pressing M > X (mirror along the X axis). Then bake the ao again. Another way to do it is by flipping your normals, but your sculpt will still be inside-out in SL and you’ll have to correct that in world.
Hey, great tutorials thanks to them i tried making sculpts again and succeeded this time xD
Anyways i had problem with baking ambient occlusion and i couldn’t find answer here so i googled a bit and found answer. Now i know the answer i think you should mention it here, but i might be wrong i’m a novice at this: my problem was that for some reason ambient occlusion was turned off in rendering (no idea why) so i had to go to world tab and turn it on. Before i did it whole image rendered was black and no matter what settings (i even through i broke the blender xP) then turned it off and bam there it was with no problems.