problem with Rendermap's Ambient Occlusion

[illusory]

Hello,

I'm trying to create an ambient occlusion map with the rendermapper. Problem is, it doesn't come out the way it did when i used an ambient occlusion node on the object, tweaked all the settings to my liking, and rendered it.

I notice that the rendermap's ambient occlusion parameters lack two of the settings that are in the AO node i am using as the object texture. Rendermap doesn't have either 'Maximum distance' or 'Output mode', which i needed to use. So where is Rendermap getting this information? Nowhere, it seems, because if i set the rendermap's AO settings (that exist) to the same as the ones in the object material AO node, i don't get the same result.

So, i figure, i'll forget AO in rendermap, and just bake the 'surface color'. Because the material on the object is set up to be ambient occlusion only. So it should work, right? The AO should be my surface color. But it doesn't work. All I get is a solid color, the 'bright' color, and none of the dark color detail which should be there. Why not? They show up nicely in a render done of the same object.

The basic result i get with rendermap ambient occlusion is very dark -- not at all the typical ambient occlusion result which is mostly bright with darkened corners. There is nothing in the manual on this -- or why the most useful setting -- 'Maximum distance' -- is absent from rendermap... ('Dist. from surface' under 'virtual camera' doesn't do the same thing)

I'm sure someone here has used rendermap for AO, it seems a basic thing. How do you get it to work?

thanks,
NJ
two pics included, one the result when using rendermap to map the surface done with AO node, the other the result with rendermap. Neither correct.

Br_1and4_AOMap.jpg

Br_1and4_AOMap_testSC.jpg

[Cryrid]

May I request a picture of what it looks like rendered with the AO (where it looks correct), and possibly a screenshot of it in the viewport, shaded mode + visible normals? Inverting a test mesh creates identical results to what you're getting.

[redmotion]

The results aren't right because you've missed something at some point. You should give people more info about what you're trying to do as in ALL the settings. Considering this has now been going on for days on end, why not post the zipped scene file HERE? Someone can take a look at it and see where you're going wrong.

[Hirazi Blue]

Considering this has now been going on for days on end

I assume you refer to a hitherto unmentioned other forum?

[illusory]

Cryrid, here's an image of a section of the model with just the AO, just the cluster mapped in my original post. I want to send you some screen shots of viewport and settings, but my screenshot software is not working at the moment. (and yes i need software because Prt Scr has not worked since utilizing the 3 gig switch in windows...). But the polygon normals are all facing inward on the model, as it is an interior render.

I'm using the AO node straight into the surface port of the material, but I've also tried it plugged into the ambient port of various illumination shaders.

Redmotion, i certainly hope you're right that i have just missed something somewhere, but i really can't upload the scene file. Perhaps you can tell me what ALL the settings means, and i can take a stab at it. I have turned off the lights, and FG for this AO attempt. AO settings work for the frame render as you can see. And I've tried both 'surface and illumination' and 'surface albedo' in rendermap. Checked that it's set to the correct UVs, everything else is left to default settings, except the file format -- and i've tried several of those.

I'm using several UV maps on this object, with associated clusters. The Uv maps are good, have been working well with other textures. I've tried applying rendermap to the whole object, and applying it to the cluster. I get the same problem whatever cluster i try to rendermap. I've tried deleting existing rendermap and reapplying.

I have XSI Essentials 7.01. Planning to upgrade soon to current version -- does rendermap get better with current version?

Any other settings i might need to look at?

thanks very much for everyone's advice,
NJ

justAO.jpg

[rray]

just some quick ideas without knowing any details... maybe 1 of them applies here
* materials on polygon clusters override the object's materials
* why several UVs for the object?
* UVs can't be "associated" with clusters they're always defined for the same (full) sample cluster

[redmotion]

does rendermap get better with current version?

No.
(In fact, I'm currently investigating [g]iles lightmapper, which is free, as an alternative for lightmapped objects for game engines. Not particularly user friendly though...)

I didn't realise that you were working with clusters. For a recent test I tried rendermapping an object with clusters and had no luck. That may be your problem.

Try this: if you select the clusters you want one by one, then rightclick and select > extract polygons > delete. You'll have the cluster as separate mesh. Get rid of the clusters on it, then try rendermapping them individually (you can use Create Polygons > merge at a later stage - the clusters get recreated) or you can select more than one object and rendermap them all at the same time. See "RenderMap, multiple objects" in the docs.

[Cryrid]

Cryrid, here's an image of a section of the model with just the AO, just the cluster mapped in my original post. I want to send you some screen shots of viewport and settings, but my screenshot software is not working at the moment. (and yes i need software because Prt Scr has not worked since utilizing the 3 gig switch in windows...). But the polygon normals are all facing inward on the model, as it is an interior render.

If that's the case, the AO rendermap uses seems like an accurate/expected result given it's options (the map is lighter around the openings, darkest around the corners, and the rest being generally dark due to the faces being in the way - you'll probably start to see different results if a wall were deleted). I'm assuming it's a long rectangular hallway here; I'd just rescale before baking and revert it back to normal afterwards. That works fine enough in my tests.

Then again, AO-plugged into surface or a color_sampler worked absolutely perfectly for me, which may be where your clusters come into play as I haven't been using them. It's a shame the scene can't be posted, it really does strike me as a 20 second fix : /