Hi everyone,
I'm hoping someone can help me with a question or two about displacement maps.
I'm modeling a superhero, and I'd like to have a logo on the chest portion of his uniform stick up 3-dimensionally. So I thought I'd use a displacement map.... something I've only toyed with before, which explains why I'm asking for help :)
I was under the impression that a displacement map is similar to a bump map in the fact that it keys on black and white. That is, if the texture one wants displaced, is colored in black, then attached to the displacement node in Poser, and the value dial is set to whatever the user desires, the rendered product would show that portion of the texture as sticking out and away from the model it's applied to. But apparently I'm wrong. Because I colored the logo in black, saved it as a .jpg file and applied it to the displacement node. Long story short, I set my displacement dial anywhere from 0 to 5, and rendered it multiple times, and the texture just looks flat.... it shows no displacement at all. So I thought maybe I had in my mind reversed the roles of black and white, so i changed the logo to white and repeated it all. No change. Still a flat texture with no 3D look to it.
So I guess there's much I do not understand.... what am I doing wrong? Do I just not understand the whole concpet of displacement maps? I'm sooooooo confused!

Thanks in advance for any wisdom anyone can impart -

Attached Link: Displacement Video

Not a problem :) Displacement maps are a little bit more comples than bumps.  First of all they are based on 3 colours, black white and mid grey.

Mid grey (127, 127, 127) will not displace the mesh at all, black will add a negative displacement and white a positive displacement.

The other thing is that Poser wont render displacements by default, you have to turn the option on in the render settings.

This video might help

John

If no displacement shows up at all, maybe you did not enable displacement in the render settings?

By the way, Black does not displace the mesh, mid grey does displace it. If you want grey to be then neutral color, you have to subtract 0.5 from your displacement map with a math node.

Here is a link to a BB posting about this

As posted by the others, it seems that displacement is switched off in your render settings. 

Well, y'all were right. I didn't toggle on the "use displacement maps" setting in my render. I did so, and it's still pretty messed up. Seems that the dial for the displacement node is incredibly sensitive. I got it to finally displace somewhat, but in doing so, it messed up the surrounding texture. I'm not sure how I'm going to handle it at this point. I may just make a 3D prop of the logo and use that, attaching the prop to his uniform. Makes it tough when I work with the 3D surface of the uniform and the underlying musculature of the superhero's chest, but I'm having a heck of a time with the displacement map.
I'll have to think on this for a while.

A displacement map is reliant upon the poly count underneath it. I'm not sure if that is part of your problem or not but I would recommend a normal map as that will yield great benefits and move with the mass under it.

Hope this helps

Quote - A displacement map is reliant upon the poly count underneath it.

Where do people get these totally incorrect ideas from?

Have you tried it? I can displace a single polygon to look like anything at all with any amount of detail.

The OP needs to show the material settings and at least a reduced version of the actual map.

The amount of displacement may seem sensitive if you are unaware of your units.

If your Poser Display units are Feet, for example, and you type in .5 for displacement amount that is 6 inches of displacement. On a ground plane 70 feet across, this is probably ok. On a prop that is only 5 inches wide to begin with, this is an insane amount of deformation.

Black is the number 0.
White is the number 1.
Gray values are numbers between 0 and 1.

The amount of displacement is the numerical value of the map times the displacement amount entered in the displacement channel.

If you use math nodes, you can further offset andt scale the map. For example, subtracting .5 from it makes BLACK = -.5, and WHITE = .5. The total distance between white and black is still controlled by the displacement amount.

You need to think about the total distance between the white (most displaced upward) and black (least displaced upward, perhaps even downward depending on the math you use). If, for example, you are doing a little bit of raised cloth, the number should be similar to .05 inches. If you set your Poser Display Units to inches, you could just type in .05 in that case.

Look here. This is a single polygon - a one-sided square. It is about 10.32 inches across.

I did a screen grab of part of this thread and used it as a displacement map. The displacement amount is .1 inch.

> Quote - Not a problem :) Displacement maps are a little bit more comples than bumps.  First of all they are based on 3 colours, black white and mid grey. > > Mid grey (127, 127, 127) will not displace the mesh at all, black will add a negative displacement and white a positive displacement. > > The other thing is that Poser wont render displacements by default, you have to turn the option on in the render settings. > > This video might help > > John

Displacement maps are not more complicated than bumps. They're identical, but for the difference that a bump map only alters normals, not positions.

Displacement maps are not based on 3 colors. They are based on numbers. An 8-bit image has 256 possible different numbers in each pixel. A 16-bit image has 65536 possible different numbers in each pixel. For most small-scale displacement, an 8-bit image is adequate bit depth. For large-scale displacement with small scale features included, an 8-bit image is not adequate, and a 16-bit TIFF should be used.

Procedural displacements (numbers generated with nodes instead of images) do not suffer from the bit-depth limitations, and all possible displacements can be represented with accuracy more than sufficient for any purpose. For example, I can deform a single polygon to look like a section of a sphere, using math. See image above.

I hate to say it, but a lot of what you're saying is a bit beyond me... math is definitely not my strong suit. But here's a sample of what I'm trying to do. You can see in the image my texture map and my displacement map. Also you can see how it's turned out. The displacement dial is set at .05 and this is how the star logo looks. It's "lifted a little bit away from the rest of the map, giving the appearance of a 3D logo, but I'd like it raised a little more. But when I do, the rest of his uniform balloons up and he looks like a cross between Captain America and the Michelin man. plus, the star gets all deformed across the top. You can see the first hint of that here, and it's only set at .05. I'm not sure what my Poser units are set at or how to change them. But to bottom line it, what am I doing wrong to make it turn out this way, and how can I fix it?

I can't see your whole displacement map, only a sliver. And the render is so tiny I can't make out the nature of the artifact. You didn't say what your displacement map resolution is, either.

So I can only guess that one of the following is true:

• The map is not drawn accurately, and has a mis-shapen star point in it. (Zoom in and look at the displacement map in detail. Does it look right?)

• The map is so low in resolution (total pixels across and down) that it cannot accurately represent the details of the star shape. (Start with a bigger map before you draw the star on it.)

• The UV mapping  of the chest area is not correct and actually has a flaw that distorts the star shape. (Put a regular pattern on the cloth item, something with lots of straight parallel lines - are they straight when rendered?)

As for the bloating, I had assumed that the explanation was simple enough, without having to get into any sort of real math. Gray is not 0. For the area that is not-a-star, the color you have is gray, not black. You need to either re-draw this with black for not-a-star, or simply subtract the exact same gray value (or its equivalent number) from the image map, using a Color_Math node or a Math node, set to Subtract. Color_Math would be easier. Plug the image into Value_1. Set Value_1 to white. Click on Value_2 to activate your color sampler in Poser, then click on the gray in the preview of the displacement map. This will automatically neutralize the gray value.

Well thats me told :) my slight if not very well put point was that bumps can only move in 1 direction away from the mesh, whereas displacements work in 2 direction away and into the mesh.

Appologies for my lack of mathematical genius I was only trying to be helpful.

John.

Quote - > Quote - Not a problem :) Displacement maps are a little bit more comples than bumps.  First of all they are based on 3 colours, black white and mid grey.

Mid grey (127, 127, 127) will not displace the mesh at all, black will add a negative displacement and white a positive displacement.

The other thing is that Poser wont render displacements by default, you have to turn the option on in the render settings.

This video might help

John

Displacement maps are not more complicated than bumps. They're identical, but for the difference that a bump map only alters normals, not positions.

Displacement maps are not based on 3 colors. They are based on numbers. An 8-bit image has 256 possible different numbers in each pixel. A 16-bit image has 65536 possible different numbers in each pixel. For most small-scale displacement, an 8-bit image is adequate bit depth. For large-scale displacement with small scale features included, an 8-bit image is not adequate, and a 16-bit TIFF should be used.

Procedural displacements (numbers generated with nodes instead of images) do not suffer from the bit-depth limitations, and all possible displacements can be represented with accuracy more than sufficient for any purpose. For example, I can deform a single polygon to look like a section of a sphere, using math. See image above.

Guys. Let me publicly apologize. I came off snarky and didn't mean to.

I wasn't even looking at who I was responding to, so please don't think I was attacking you personally, as I wasn't even aware of who "you" is.

I was in a meeting for 14 hours yesterday and was about to lose my mind. When I posted last night, I had no patience. I'm about to go into another full meeting day and I'll probably be a raving maniac by tonight.

So, let me rephrase, quickly though because I have to go to work.

The ideas about displacement from other apps, or the opinions of other posters in other forums - leave them there. I have done thousands of hours of experiments with Poser displacement. I have written about it for 3 years and I have to repeatedly fight with a bunch of "memes" that won't go away. Despite all my efforts, certain incorrect ideas keep cropping up, and they simply don't apply to Poser. You guys are not stupid for repeating them, I know that. I'm just impatient that they won't go away. I am arrogant. I think you should read everything I've ever written, perhaps tattooing some of it to your arms. :)

Displacement is based in numbers. Pictures turn into numbers for this purpose. Other apps have a neutral value in some form of mid-gray. Poser's neutral value is black. By using a math node (or color math) you can change Poser's neutral value to anything you want.

Thanks for the info Dude, would you have a link to somewhere where I could see the usage of the math node, I can't quite picture what and where the math node would plug in to.

Thanks

John.

PS I have enough tattoos thanks, won't be adding any more until these drop off :)

Quote -

Displacement is based in numbers. Pictures turn into numbers for this purpose. Other apps have a neutral value in some form of mid-gray. Poser's neutral value is black. By using a math node (or color math) you can change Poser's neutral value to anything you want.

Fugazi, take a look at the thread bantha linked to. It's got a series of images by bb using a maths node to achieve correct usage of a displacement map in Poser.

Here ya go. I'm linking you right to the node setups or similar verbal explanations, but readers might find it worthwhile to peruse all the posts in these threads.[

http://www.renderosity.com/mod/forumpro/showthread.php?thread_id=2773619&page=3#message_3474662](http://www.renderosity.com/mod/forumpro/showthread.php?thread_id=2773619&page=3#message_3474662)

http://www.renderosity.com/mod/forumpro/showthread.php?message_id=2949080&ebot_calc_page#message_2949080

http://www.renderosity.com/mod/forumpro/showthread.php?message_id=3362953&ebot_calc_page#message_3362947

These next three talk about bump - the "neutral value" problem actually appears with gray bump maps as well. It's just not as obvious. If you don't pay attention to it, you can end up with artifacts (virtual bumpy surface crossing itself).

http://www.renderosity.com/mod/forumpro/showthread.php?message_id=3369942&ebot_calc_page#message_3369942

http://www.renderosity.com/mod/forumpro/showthread.php?message_id=2950918&ebot_calc_page#message_2950918

http://www.renderosity.com/mod/forumpro/showthread.php?message_id=3027348&ebot_calc_page#message_3027348

One more

http://market.renderosity.com/mod/forumpro/showthread.php?message_id=2943106&ebot_calc_page#message_2943106

I'll stop looking now. I've probably written about this in 30 threads. Why it is not a sticky yet, I don't know.

According to the search engine, I've mentioned the word "displacement" in 281 different postings in this forum.

frankly for something like the star you aren't really getting much bang for your bucks by using a displacement over bump. you probably wouldn't be able to tell the difference in a render between the two unless captain america was facing in direct profile where you would see the profile of the star sticking out of the chest. changing the outline of the mesh, (which bump woudn't do) in any other position I doubt that you would notice a difference.

I notice that the emblem is part of the texture.  I usually decal those emblems to the costume in the material room.  It saves having to create a hi-res texture map for the occassion.  Wdupre is correct to point out that the displacement is actually negligible unless you render a closeup of the character.  The following links show good old Supe sporting decaled emblems on his costume.  The texture and color were created in the Material Room.

http://www.renderosity.com/mod/gallery/index.php?image_id=1794377

http://www.renderosity.com/mod/gallery/index.php?image_id=1808005

IIRC, I did try displacement maps but am not sure if they are actually in these renders.  I do have a Green Lantern costume WIP which does have a very good displacement map I created.

Quote - A displacement map is reliant upon the poly count underneath it. I'm not sure if that is part of your problem or not but I would recommend a normal map as that will yield great benefits and move with the mass under it.

Hope this helps

The polys are subdivided at render time based on your shading rate parameter.  The smaller the number, the more polys are divided.  It is based on pixels, not the model's polygons.

Amidst all of the useful links and tech talk is a key point you should always remember.  You need a math node to make a map displace both above and below the surface.  Without a math node you can only make a material displace in or out (by making it pos or neg), but can't make it do both.

(Bagginsbill, I really want to try that study aid where I eat chocolate while reading your posts then I would smell chocolate whenever I got stuck on something.  I wonder if that would help me remember better?)