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Need advice buildings in blender

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hey guys,

I'm currently making a building,  it looked great. The only problem I have right now is baking ambient occlusion of the building. The outside appear to look fine, but the inside looks very dark. I also have the same problem when i light a lamp from outside through the door and bake full render, it also appears that the interior is not lit. could you please help me on how to have an AO and full render bake of the interior to be well lit just as the outside? 

thankyou very much

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I am going to take a stab at this and others can refine (or laugh at) my comments.

My very first Blender house was very dark inside also. For me, that worked as it was an adobe house with small windows and honestly they ARE very dark inside -- so it was true to reality.

I see a few ways to fix this. You could of course lighten the ambient map in your graphics software adjusting the contrast at the same time to get a look closer to what you want.

You could also add extra lamps INSIDE the building before baking.

You can also (depending on your build) take the roof "off" in blender by moving it to another layer so that the sun shines in from above. This will not be REAL of course but it might give you what you want. I frequently move parts of a build to other layers before baking to eliminate dark shadows where I DON'T want them to appear (under pillows for example - U see the world with Windlight shadows most of the time and I am not too fond of cast shadows built in).


I am guessing there is also a way to lighten the ambient map in general within Blender so I'll let the smarter folks respond and watch and learn :D.

 

 

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Are you using Blender? If so, click the globe (world) symbol on the properties panel. Turn on AO (I guess you already did). Then find the "Gather" section. This has two settings that determine how far away surfaces do(not) cause AO shadowing. They are the Attenuation: Distance - surfaces further away have no effect -  and Attenuation:Falloff - how fast the effects lessen as surfaces get further away. If you play with those, you should be able to find settings that prevent the darkenning of the inside withouit losing the needed AO.Also, always turn on the "Normalize" option in the "Bake" section of the Render (camera icon) tab. Otherwise you will likely get AO that is too dark overall.

If you like excessive AO, as most people seem to with buildings, you might need to do a separate bake for inside and outside, using the appropriate parts of the two images combined in a final AO texture. You can also use a function like "Color->Curves" in Gimp to adjust the AO selectively in different parts of the image.

Don't forget that SL advanced lighting model includes some (quite faint) AO. Although probably only a minority have it turned on, the AO you use gets superimposed on that for those that do.

 

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Nice one Drongle.  I thought your answer  well worth a couple of pics  :)

AO_Default.png

 

AO_Gather.png

 

Will the people living in adobe homes now demand better living conditions ? lol

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Good, especially imcluding the samples setting. Default is grainy. I usually use higher falloffs than that, up to 20 for small objects, but then I like rather subtle AO.

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WOW. Mine has never been THAT dark - LOL. THAT IS BLACK (smile).

 

See I knew you guys were smart *wink*. Should I ever actually upload something again, I will take note :D.

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Chic Aeon wrote:

You could also add extra lamps INSIDE the building before baking.

You can also (depending on your build) take the roof "off" in blender by moving it to another layer so that the sun shines in from above. This will not be REAL of course but it might give you what you want. I frequently move parts of a build to other layers before baking to eliminate dark shadows where I DON'T want them to appear (under pillows for example - U see the world with Windlight shadows most of the time and I am not too fond of cast shadows built in).
 

I think adding lamps inside the building will not help for ambient occlussion. Ambient occlussion is not caused by lights, you must understand it as self shadowing of objects. It can be in one object, but when you have several objects in a scene, they can also influence each other.

When you make a box with a lid upon, the lid will cause shadow inside the box. When you make a box with a lid next to it, the box and lid will not influence each other. Both box and lid will have a bright inside, with a little touch of shadow on the inside corner.

Same as with the box example, taking of the roof helps (at least for the upper floor). Because the roof will no longer cause shadow inside the house.

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Well I have gotten around the darkness in that manner (by moving lights around) so apparently it can work in some situations :D.  And I have had empty boxes that were dark inside with no "top" on them. My guess is that we just work differently. There are SO MANY WAYS to do things in 3D programs! 

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I would like to second Drongles note that you may want to map the inside separately from the outside (or even in more parts if you have a large building). If you want a fine grained smooth AO map, that would be very difficult to do in the example photo even if you used a very large resolution to map too. What happens is that the small square on the png file get stretched to a full sized wall and consequently even a 2048 texture gets blotchy. Even larger to start with (obviously you are not uploading this size) might help, but a better bet for fine texture would be to do larger sections.

You CAN use the same ambient areas for different parts of your build, so for example if you had two plain walls of similar size, you could map the first one and make your ambient bake and then map the second wall to that same area -- thus reusing the map and getting more bang on your texture real estate area. You do need to make sure that the proportions are the same or similar or that will not look good.

And I found the ambient for my casita. Adding a 512 pic here so that you can see the different look you get  with the different methods. I left the interior fairly dark as I said as that actually is how they look in RL.

 

casita-adobe-ambientEX.png

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That might be the case, Chic. I work in Cinema 4D.  Though I would think the principle of ambient occlussion is the same in all programs.

When you bake the texture itself, (the diffuse map) that is different. Lights can do a lot to make it look good. You can bake as well shadow maps that are influenced by a light source.

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AO bakes in a unlit scene as it is completely light independant. So you may have some thing else going on with how you are setting up your scene relating to the settings you've used for AO, such as baking with  normalize unchecked, your choice of ao blend mode, the attenuation distance and fall off settings,  the number of samples and selection of raytrace vs. approximate.  With the wrong (or right depending on what you are looking for) settings you can easily ao bake a box with no lid that is dark inside as well as one with very little ao influence that will be light.

 I think it's incorrect to say that lights will correct an ao problem and will confuse beginners who are trying to get a better handle on baking ao.

 

Edited to add that I'm referring to ao baking in Blender.

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Added notes:

Before baking out the AO map its often a good idea to add a ground plane for your model to sit on.

If your AO map looks a bit grainy when you are using it in Gimp or Photoshop to make your final texture giving it a tiny bit of blur can make it look a lot better.

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Good point about the ground plane,  Aquila.  And up-ing the samples also makes for a much smoother/nicer ao result although it takes a longer time to bake.

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Thank you all for this thread. My question is, what settings did you use for your UVs in Blender? I'm currently fighting with my UVs and can't seem to get them to unwrap with the correct aspect ratio.

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Two suggestions:

1) Try selecting all the UV islands and pressing CTL A with the cursor in the UV space to average the scale of all islands

2) Set your 3d view to texture and apply a temporary UV grid in Blender.  This is an option available to you when you add a blank texture in Blender.  There are two grid choices or you may find one you prefer that you can upload.  Select the UVs and add this temporary grid texture and  manually scale your UV islands so the grid appears even over the entire mesh.

 

Edited to add:  Generally one does not get perfect results after unwrapping.  More work is usually necessary to scale, move and rotate your UV islands around to get the desired results based on the scale of the texure, the direction of the texture and if it repeats, etc.   The unwrapping part is just the beginning of the process.

 

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That's very helpful, thank you. I will try that. Would you suggest to begin with a smart unwrap or cube or some other starting point? Does it make sense to create the seams or no? Before I manipulate the UVs I mean.

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There's no general advice that can be used in all cases, but I will mention something that I think eludes beginners which is you can selectively unwrap a mesh's parts using different methods.  You don't need to commit yourself to a single unwrap choice for the whole mesh.

For example you may want to "project from view" some group of faces into a UV island  and then use smart UV project, etc. for other selected parts depending on various factors.  It takes a while to get good at this and it's always an interesting challenge.  Some folks hate it, but I rather enjoy the "puzzle" aspect.

I never use the cube, cylinder or sphere projection, btw.  Generally I define my seams and use "unwrap"  or I use "smart UV project" and then perhaps move/rotate/scale and sew islands together.  And often I use "follow active quad" to get a grid layout.  Sometimes I use the sculpting tools to relax the UVs if needed after I'ved unwrapped organic models.  In certain cases I use the mirror function, etc.  

There are lots of options and it takes some time exploring how and when these options are useful and it helps alot to practice, but the up-side is you have all these tools at your disposal to get optimum results.  To get really good at this you have to look through the menu options in the UV window and search out a tutorial for each option.  There's not a whole lot out there relating to the intricacies of uv mapping in blender, but I managed to teach myself through sheer perserverance.  And don't be afraid to look at tutorials for other 3d programs.  The tools will be named differently and there may be other options, but you will learn a lot about the UV process and the rational for how different types of  3D mesh is deconstructed into it's 2D UV islands.

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mtwtfss71 wrote:

That's very helpful, thank you. I will try that. Would you suggest to begin with a smart unwrap or cube or some other starting point? Does it make sense to create the seams or no? Before I manipulate the UVs I mean.

Well I found this thread again without TOO much searching. I KNEW I would need it some day. And I see I never came back so never answer this question.

I gave up Smart Unwrap around month 6 with Blender :D. Good at first but by hand is much better. I use a variety of mapping "settings" depending on the project. Sometimes project from view works very well. Other times I mark my seams appropriately (lots of video tutorials on this but it does get easier the more you practice :D) cross my fingers and hit the unwrap button.

Most of the time these days the unwrapping goes well. It did NOT in the beginning. Eventually I think folks (me anyway) get into an intuitive sort of ZEN mode and things just click.

One of the important things to remember when unwrapping is to keep your pieces (or islands of faces) in the same scale. I read a thread lately about how to average the scale in Blender and I tried that. I was NOT happy with the results.

Again, with practice it gets easier. If I am wondering if I got the scale correct, I use a 2048 square of fine print fabric (any patter would work) so that I can easily see if something is mapped "larger" than other pieces.

Hope that helps someone along the way.

AND my main purpose for writing is that I used this info today. I remembered it was in the World tab but not much beyond that. Worked swimmingly so thanks for this info.

I still don't know how I got things lighter before by using lamps, but I did note that I didn't have anything checked in WORLD and apparently never had. I honestly hadn't even been to the WORLD tab until today LOL.

Who knows, we stumble along and now and then make something good *wink*.

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