When we use ambient occlusion on a model Poser generates a temp map for use during rendering.  Where is this stored and how can I output it to use later?

I don't think Poser generates a temp shadow map for AO. AO is done using ray-tracing, not shadow mapping.

On the other hand, directional lights, when set to depth-mapped shadows, do use a map. However, that's a depth map, not a shadow map, and you couldn't use it anyway for post-working a render, because it is from the point of view of the light's shadow camera, not the rendering camera. The perspective is totally different.

Am I correct in assuming you want a shadow map - something you can layer on the render later and multiply with the render to darken it? If so, let me know. It's pretty easy to make that.

Thanks bagginsbill.  What I'd like to do is output the AO to multiply over a texture map and bake in some of that shadow.  I don't want to bake in regular shadows, only the stuff that accumulates in the crevices for a dirt map.

Wouldn't that be a bit of a single, specific use only thing? Something that would only work with lights in one position relative to the lit object?

For example, looking at the building in your sig, you want to bake the AO shadows into the pink stripe texture where there are corners and crevices on the 3D object? Poser can't do that. The only sort of shadow baking it can do is for the actual render, not for the underlying texture. Other renderers can bake textures, but not poser.

What I thought you were after was something like the attached images. Instead of a normal render (left), you can make a shadow's only render (right). Then you can render over and over without expensive shadows, and combine the shadow render in post. It's only useful for when you're trying to fine-tune shaders and such, and you don't want to wait a long time to get the shadows each time. You render the shadows once, then do all your evolving tweak renders without shadows, and finally combine them in the end.

Quote - Wouldn't that be a bit of a single, specific use only thing? Something that would only work with lights in one position relative to the lit object?

Not at all. The crevices, nooks, and crannies exist regardless of lighting. By baking the crevice shadows into the texture, you can skip doing it in the 3D render altogether. For many props, such as an ornately carved piece of wood, baking the AO shadows in is a big time saver.

This image (by Ajax) is a good example.

He generated "dirt" in the crevices using an Ambient_Occlusion node and ray-tracing. However, this is very time consuming. If you could "bake" those dirty areas into the UV-mapped texture, you would never have to use the AO node again on that prop.

The reason this is compelling is that drawing those dirty areas by hand on the texture map in 2D, and getting them in the right places, is excrutiatingly difficult. Worse, if you moved any of those features around a little bit, you'd have to draw the dirt on the texture all over again.

Thanks for the shadow-only tip.  I'll use that too.  I am writing my shaders now so that will help. 

modus,
Ambient occlusion finds intersections and darkens them.  I want that not for a shadow, but to use as I paint textures to help create a dirt mask.  Is there any way to capture that information and use it?

Muralist,

I've heard that Max and Maya can both do texture baking. I'm assuming you don't have these apps.

Perhaps you could enlist the assistance of some fellow Rendo members. Maybe you could get someone who has Max or Maya to take your prop and bake you an AO crevice map for it. Once you have that map, you could use it in the material to drive dirty effects, using Blender nodes. You wouldn't have to generate a new crevice map unless you changed the geometry.

you may be able to do it in another app

I found this for Blender - http://www.blender3dclub.com/index.php?name=News&file=article&sid=47 which seems to do what you want...

looks like an interesting idea if we can do it..

Blender has texture baking now?!?

I've used Blender in the past, but not in a couple years. They're really adding a ton of features to that app. You guys know its free, right?

free but with the interface from hell :)
C4D can also output AO passes

If you want a separate occlusion pass from Poser you can get it using the RenderPasses.py
that comes with Poser.
You can render separate ambient and occlusion passes.
They are being saved in the file format you've set as default for image export, usually .png

For even more control you should have a look at "Advanced Render Settings" by Semidieu at RDNA.

Martin

that renders the view of the object in the viewport tho.. not onto the mesh's texture map / UV space...

Quote - that renders the view of the object in the viewport tho.. not onto the mesh's texture map / UV space...

I understand that.... Just thougt it an option, because muralist was asking about the temp files used by Poser during rendering.

Still, I am curious... how do other programs "render" the AO effect of a part of a model not seen by the cam ?

You can do that using XNormal.
This app allows you to render a AO map from your obj (uvmapped). You only have to take that AO map and mix it with your texture in a paint program or directly in Poser with nodes if you want :)
I use it all the time to bake AO ^^

Quote - You can do that using XNormal.
This app allows you to render a AO map from your obj (uvmapped). You only have to take that AO map and mix it with your texture in a paint program or directly in Poser with nodes if you want :)
I use it all the time to bake AO ^^

Thanks, Vince.  Exactly what I was looking for. 

Quote - Still, I am curious... how do other programs "render" the AO effect of a part of a model not seen by the cam ?

A 'render' is just the process of converting geometry to pixels. For speed reasons, most renderers only use geometry the camera 'sees' for the pixels, but that doesn't mean they can't use whatever part of a scene they like.

For baking the AO onto a texture like the OP wants, the renderer just runs the render process on the entire object and instead of displaying the result on screen, stores it in a texture file instead. The UV map of the object serves as a guide as to where each pixel goes in the file. eg if the UVs of a part of an object are (0.5, 0.5) ie exactly in the middle of the texture, and that part of the object renders black in AO, the renderer copies the pixels to the middle of the texture. This is then repeated for all parts of the texture to get your final 'bake.'

And this can be done for any kind of rendering, AO is just an obvious example. eg you can do it for procedural textures, lighting, GI, bump maps, SSS etc. It's used whenever you want to do the calculation of a particular effect only once and then just reuse it again and again to save rendering time, like in an animation.

Thanks for the explanation, ghonma!

 Have you looked at Advanced Render Settings:

[ Shaderworks Advanced Render Setting

](http://www.runtimedna.com/mod/bcs/index.php?ViewProduct=3322&TopID=166848)

• 1 main script for Poser 7
• 1 main script for Poser 7 Pro, with new features (gamma correction and HDRI output
• Color Render passes: Diffuse, Specular, Ambient, Color, Shadow, AO
• Special Render passes: Wireframe, Geometry, Displacement, Altitude, Z-Depth.
•  

Quote -  Have you looked at Advanced Render Settings:

[ Shaderworks Advanced Render Setting

](http://www.runtimedna.com/mod/bcs/index.php?ViewProduct=3322&TopID=166848)- 1 main script for Poser 7

• 1 main script for Poser 7 Pro, with new features (gamma correction and HDRI output
• Color Render passes: Diffuse, Specular, Ambient, Color, Shadow, AO
• Special Render passes: Wireframe, Geometry, Displacement, Altitude, Z-Depth.
•  

This script produces AO on the render, the OP wants AO as a texture map, following the UVmap of the obj. Exactly as Stonemason uses for his texturing, see his Hard Surface Textue Painting tutorial :)

so.. that Xnormal, I put in a UVmapped OBJ and it'll output the AO? oooh I likey.... faster dirt maps! lol

Quote - > Quote -  Have you looked at Advanced Render Settings:

[ Shaderworks Advanced Render Setting

](http://www.runtimedna.com/mod/bcs/index.php?ViewProduct=3322&TopID=166848)- 1 main script for Poser 7

• 1 main script for Poser 7 Pro, with new features (gamma correction and HDRI output
• Color Render passes: Diffuse, Specular, Ambient, Color, Shadow, AO
• Special Render passes: Wireframe, Geometry, Displacement, Altitude, Z-Depth.
•  

This script produces AO on the render, the OP wants AO as a texture map, following the UVmap of the obj. Exactly as Stonemason uses for his texturing, see his Hard Surface Textue Painting tutorial :)

Sorry Guys, My bad, I did not completely follow where it was going...
That tut is VERY cool BTW!

Synpainter

Poser 7 has a render passes script in the script menu in the RenderControl folder. It outputs an occlusion render pass, an ambient render pass, and shadow render passes for each light.
Obviously, it will only render out a pass from the view of the camera, however, using an orthogonal view you could use the occlusion render for dirtying up a texture map as in Stonemason's tutorial (linked in the above posts).

Quote - Blender has texture baking now?!?

I've used Blender in the past, but not in a couple years. They're really adding a ton of features to that app. You guys know its free, right?

Yes, blender has Texture, AO raytraced and aproximate, Normal and Displacement bake, and a lot of very underestimated great features like the sculpt tool to make morphs, and is not that hard to learn, if I did everybody can :-)