Ambient Occlusion not occluding object

[Pamela Galli]

Or maybe the object is not occluding? In any case, a doorframe has no effect on the AO bake. It has a material assigned, normals normal, I can't see any reason for it. Other things are behaving fine.

[Rahkis Andel]

How are you baking these maps?

What baking method you use will determine how other objects affect the bake.

I explain in pretty good detail how to bake ao in this thread.

It isn't as simple as selecting your object and pressing "bake". If that's what youv'e been doing, hopefully my thread will help.

[Pamela Galli]

Thanks Rahkis, but I did not see anything in that thread about occluding objects.

[LepreKhaun]

After modelling, texturing and UVW mapping, be certain you do each of these steps:

In the "Properties" panel click the "Render" button (the camera'icon).

Scroll down to the "Bake" subsection and click the triangle to expand the available options.

Click the "Bake Mode:" drop-down menu and select "Ambient Occlusion" from the list.

Then select "Normalized" and ensure "Clear" is active..

Finally,  click the large "Bake" button at the top of the sub-section to render the image.

Progress indication of the bake will differ depending on whether you are in Object or Edit mode but the result will be the same.

Once baking is finished,  in the "UV/Image Editor" click "Image*",, name the file, select a location to save, select a 'loss-less' image format (TGA, TIF, etc.), select "Relative Path" if required and then "Save As Image."

 

[Excerpted from http://www.katsbits.com/tutorials/blender/character-5-texture-baking.php which showed me what I had overlooked when I was learning this]

 

[Drongle McMahon]

Do you by any chance have another copy of the door object with the same image in the UV editor but located far away from any occluding objects? If so, that could be overwriting the baked occlusion. It usually gives more obviously garbled results though.

[Pamela Galli]

Thanks -- I think I am not explaining very well: here is a pic that shows a part of the wall -- there is an arched doorframe the shape of which should be showing around the hole for the doorway but there is nothing.  It is like it is invisible to the AO shader.

 

 

 

[Rahkis Andel]

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Pamela Galli wrote:

Thanks Rahkis, but I did not see anything in that thread about occluding objects.

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That thread does tell you what you need to know about baking AO assuming you already understand the process -- perhaps that's the stumbling point. In my thread the floor I added was an occlusion object, as you put it.

What really matters, though is that you explain exactly what your process is for baking out your AO maps -- step-by-step. If you do that, we can tell you what you're doing wrong. Showing us your AO baked out does nothing to help us help you at all.

Edit: By the way, one thing that would cause your doorway to not show up in the bake is if it's renderability was not active -- In the outliner, you'll see an eye and a camera next to the different objects in your scene. If the camera is greyed out, it will not show up in renders or bakes.

[Pamela Galli]

That was it!  The camera icon was turned off.  Thank you so much -- that never would have dawned on me.

[Rahkis Andel]

Great!

It is usually the simple things that get us.

[Pamela Galli]

Just want to say what a valuable resource this forum is -- I posted the same question in the BlenderArtists forum and got: <crickets>

[LepreKhaun]

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Rahkis Andel wrote:

Great!

It is usually the simple things that get us.

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Isn't that the truth! It's like the legendary TV troubleshooting and repair manual that started with "1.) Make sure television is plugged in."

 

Adding that to my checklist for when I start disabling rendering of specific objects in my scenes along with a well-deserved kudo.

[Pamela Galli]

It seems to be happening again.

All of a sudden when I bake something in Blender with Full Render, AO is no longer baked with it. I can bake AO separately but with Full Render it's just the texture. 

AO is checked, and Multiply. The parts of the mesh that should be occluding ambient light have a material assigned and the camera is checked in outline. 

 

What am I missing? 

[LepreKhaun]

I've just used Gimp to combine my UVW-mapped  AO and diffuse textures.

 

I believe the whole purpose of baking an ambient occlusion map is to then combine it with the original diffuse texture in an external, 2d image editor, using the control you have there with layers and filters. Then, the blended images are brought back to be applied to the model for a better sense of depth.

 

There may be a way to control the blending of the two with nodes, but I've just started to get into that. I'm certain one of the resident experts can tell how that is done.

[Pamela Galli]

Thanks -- yes I can still use Gimp to add the AO, but full render has always included AO before. 

At this point I am thinking I should just reinstall Blender. I may have hit some button or checkbox somewhere but I have no clue what it might be. Like I am sure I did not turn the camera button off in the outliner but there it was.

[Rahkis Andel]

It may be a newly introduced bug/feature. I've never had much use for baking out everything at once, so I never noticed full render including AO.

You really want to have all the control available to you -- to fine tune the AO effect. Realize that AO is an ambient lighting trick and therefore is supposed to be applied to the ambient lighting, which we have no control of in Second Life.

It's just cheaty-fakery (Of the best kind) and as for all crafty tricks, they have to be used with care. I'd just assume not worry about it.

PS: AO usually looks okay so long as it isn't applied to something that has to move (Such as an avatar). On buildings, it tends to not matter so much, but still more control is always better.

 

[LepreKhaun]

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Rahkis Andel wrote:

It may be a newly introduced bug/feature. I've never had much use for baking out everything at once, so I never noticed full render including AO.

You really want to have all the control available to you -- to fine tune the AO effect. Realize that AO is an ambient lighting trick and therefore is supposed to be applied to the ambient lighting, which we have no control of in Second Life.

It's just cheaty-fakery (Of the best kind) and as for all crafty tricks, they have to be used with care. I'd just assume not worry about it.

PS: AO usually looks okay so long as it isn't applied to something that has to move (Such as an avatar). On buildings, it tends to not matter so much, but still more control is always better.

 

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I  agree that AO does fall under "cheaty-fakery" but until we get materials with normal maps in SL it can be used to simplify geometry in architectural builds ( see 

 for how an arched window opening could be retopoed effectively with AO) and, used judiciously, .is almost a necessity with clothing.

 

Also, it might be pointed out to the reader that the settings for the initial AO bake are controlled in the (unintuitive) World -> Gather settings. Tweaking the various settings there will benefit the final result.

[Rahkis Andel]

Yep! I agree. Like I said, it's a great trick, but the more control you have over it the better, which is why it makes sense to bake out the AO by itself and layer it with an image editing program.

Also it definitely makes no sense to me why the settings that affect baking are so all over the place. I hope that whenever the UI is re-addressed in the future, that's one of the things they tidy up.

Edit: I didn't mean "Cheaty-fakery" in a bad way. I'm a traditional artist first and foremost, so cheaty-fakery is a great love of mine.

[Pamela Galli]

There are times I do want to adjust the AO, but also times the AO is fine as it is, and I would like the option to just do a full render. But that does not seem to be an option for the time being.

 

Actually for this particular problem the thread title is not correct -- I can bake AO, just not as part of full render.