displacement map problem (shrinking when I adjust strength)

Help wanted for N.E.R.D (Neophyte Engaged in Rendering Disciplines) Ha! Too much coffee at Starbucks. Anyway, I’m following along the only in-depth realistic materials tut that I can find (http://www.blenderguru.com/tutorials/the-secrets-of-realistic-texturing/#.VGv3V75YWlL) and everything works except when I try to adjust the strength in the displacement modifier. It shrinks the object when I do. Anybody know why?

You didn’t pack the blend so I can’t see any of your images or help you with your problem. Also change the image for your normal map to non color data.

You’re better off adding Glossy component:



(ignore what’s hidden behind Color texture - it’s just to compensate for a lack of it.)

Sorry, never heard of having to “pack” a blend file. I’m new. When I packed the file it’s sized jumped to 4.3 MB (makes sense) but now the file won’t load up. I get an error message the the upload failed. Can’t be coincidence that this is the first time I’ve tried to load a packed file and the first time I’ve had a problem loading. Any ideas?

P.s. The glossy rhino thing is awesome eppo, but the look of the didgeridoo in the book I’m writing has already been defined (The Bandeliers and the Land of Indigo. Shameless promotion. :eyebrowlift:) If you have any ideas on how to make the precious metal joints look more realistic such as pitting, etc. I’d be glad to hear any ideas you might have. :wink:

thanks,
TP

You can upload .blends with up to 30 MB here - just post the download link afterwards.

Thanks, here’s the link. http://pasteall.org/blend/33021

So your question is about your displacement modifier? It gets bigger or smaller when you change the strength? Try changing the midlevel to 1 or 0 depending on if you’re strength is positive or negative. I think that is what you’re asking.

Alternatively you should know that you can plug the displacement map into the “displacement” of your material output node and it will displace it but without moving your vertices. Also I think displacement maps should be black and white. Although blender might convert it automatically for you I’m not sure how that works.

Your problem is that you changed the displacement modifier’s midlevel setting from its default value of 0.5 to 0. What this setting does is this:
A perfect displacement map is a greyscale image with 50 percent grey (midgrey) areas getting no displacement at all, areas brighter than that being pushed out and areas darker than that being pulled in. The midlevel setting tells Blender which color exactly is the point of no displacement.

As soon as you changed that to zero, this resulted in displacement pushing everything out, thereby seemingly scaling the object up with increasing amounts of displacement.

To be precise: If you plug a map into the “Displacement” input of the material output node, you’ll just get plain old bump mapping. To get “real” displacement from that you will have to enable a whole lot of highly experimental features in Blender, that may or may not work as you expect…

That’s fine - substitute Dürer’s rhino with whatever you have on plans; you had normal map node and no image there. With plain Diffuse node result usually is, well, plain.

Displacement ( it took a while for me to realize you’re after that) is probably most heavy weight thing in blender and this would be the last resort here. As it was said it should be grayscale image, higher bit resolution - better, and 50% gray (linear color space) is 0 influence on displace of the actual mesh elements which means you have to have more vertices in the mesh than pixels in your displacement texture. Any less than that and result will be washed out or jagged nothing.
Speaking Cycles Experimental render mode, Object Data tab, Displacement options - as it is said in forum - it is not fully functional in its current state, might be considered broken but sometimes might just work by sheer luck. It is enough to add texture to Output node’s Displacement input (Math node, Multiply to attenuate values) and to play with options. Be prepared for crashes though. http://www.pasteall.org/pic/80333

I had to change the midlevel when I first set up the displacement map because it was all caddy-wopas on me. I’m not sure about all the experimental stuff. Just wanna keep it simple. It worked with the tut. I followed, but it was a plane, not a cylinder. I have messed with it some more and realized that the strength setting is very sensitive and that using the arrows in my case doesn’t work well. I’m manually entering small increments and adjusting the midlevel to compensate and it looks like it’s giving me some good flexibility.

eppo, that is a cool pic you uploaded. But i’m still confused on how you did it. could you post the entire node map please?

Well, had to recreate it again… Might be a bit different this time. http://www.pasteall.org/blend/33051
No promises this will work for you - i had low grade laptop this time and it was constantly crashing on 2.72. Not so badly on older Blender version. Could depend on available RAM, Cycles growth factor or simply weather conditions, idk. Since there is this micro displacement going on you don’t want rings abruptly end near the wooden part - make room for some shadow.
Happy experimenting ;).

Roger that, thanks… :wink: