Displacement Bake WTF?

Argh!

I’ve done successful displacement in Blender many times, I don’t know why this is failing on me. Maybe I’m missing a step? I’ve tried this in 2.61 and 2.62, on both my actual project and on a default cube and neither are working for me.

My displacement maps are coming out either solid grey, or if there is any variation, it is a harsh, posterized solid color, ie, no shaded gradient between tones. Then things don’t seem to be showing up quite where I’d expect.

I’ll give the default cube examples first:

Ok, so here you see three cubes. All are unwrapped with the exact same UV seams and layout.
At left, a subdivided cube with a subsurf. At right is the Multirez object. In the middle is the Hi Poly made from applying the multirez.


I bake Selected To Active Displacement from Hi Poly to Lo Poly Subsurf and get this junk:


and the same goes for Normal Baking. Except at least there is some tonal variation in this, but it’s all clustered up as if there were two planes in the UV map.


If anyone needs a blend I can upload one. Not sure if I can attach one here.

I would REALLY appreciate some help.
Thanks.

(I’ve also been unable to do any successful baking directly from the multires. )

If anyone needs a blend I can upload one. Not sure if I can attach one here.
Yes, that’s 100 times more useful than just a few screenshots

The normal map looks like it may have inverted normals somewhere

Baking displacement from multires http://code.blender.org/index.php/2011/06/baking-from-multires-data/

Thanks for your reply, Richard.
I checked after your suggestion and the normals are all outward and consistent across the models.

Here is the blend file.
Cube_Displacement_WTF.blend.zip (1.06 MB)


This is what I get for the cube on the right with the multires modifier and baking settings

For the two other cubes I get this. Both objects need to be in the same location.


Attachments


The reason is that all the model (high poly and low poly) must be in the same exact location.

So go to Object Mode, select the low poly and press SHIFT+S then “Cursor to Selected” (or model -> snap -> cursor to selected).

Then select the high poly, press SHIFT+S then “Selection to Cursor”.

Now you can bake the displacement (but before select the high poly model first then press shift then select the low poly.)
http://i.imgur.com/mZAzJ.jpg

edit : beat to it by Richard Marklew

First. thank you.

Hmm. I could swear I tried this with them in the same location before I spread them out, but yup, this worked.
Now I gotta figure out why the same solution didn’t work on my actual project.

Ok, so this is literally “the worst shoe ever” but what the heck.

I can get a normal map working no problem.


But I need a Displacement map for Cycles, and the exact same setup, with the only change being Bake Type, and I get this:


Here is Das Blend.
Aleck_Shoe.blend.zip (1.79 MB)

I’m doing something wrong.

Thanks for help.

in this video, cannedmushrooms gets the same solid gray displacelment when his normals work. I’m not sure why it’s not mentioned in the video.

Try with a bigger object. Scale both shoes by 10. I get this displacement map. Then you can scale the shoes back down by 0.1 to their original size. The larger you scale, the greater the displacement contrast

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So to work good, displacement baking require objects of a specific size (didn’t noticed the objects in the blend were that small in term of blender units, until i looked at the N panel, very small indeed)

Interesting, i was wondering why the details were nearly invisible on the displacement map (they exist though, as if you bake on a new texture set with 32 bit float, you can try to apply this “looks like entirely grey” displacement map and see that it actually has some information , just not very obvious to the eyes) as there was nothing obviously wrong

Maybe someone with the ability to do should include this rather important piece of information to the manual, as currently it’s not wrote that object should not have very small size if attempting to bake displacement.
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Bake

If you read the docs on the displace modifier you’ll see how the displacement is calculated. Just tested with a black background with a pure white circle (value of 1). With the midpoint at zero (black) and the strength at 1 it gives a displacement of exactly 1 blender unit. This is why the size of the object is important as it seems the displacement map is a record of displaced polys as blender units. Small objects with small displacements will show very little difference in the map.

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Thank you so much Richard, you have just solved my problem, and probably many other peoples. I’ve been searching and found a few of these “all gray displacement map” threads with no good answers.
I thank you very much. can I do anything for you?

Nice, definitively this should be mentionned somewhere in the manual, i’ve seen indeed several of those “grey displace thread” without the source of it being found, would save lot of headaches from people trying to understand why the displace looks like a monolithic grey patch.