18 Replies Latest reply: Jun 29, 2012 7:57 AM by emil emil RSS

    save AI patterns with >8bit/channel?

    polyxo Community Member

      Hi All,

      I would like to create seamless greyscale patterns in AI CS6 by using typical Vector-Tools, Gradients and Transparency.

      Output however needs to be 16Bit/Channel RGB - 256 greys are clearly not enough on the Gradients, they would lead to nasty artifacts

      in the intended field of use explanation here

      I realize that AI is 8bit and that internal Image-Conversion from Vector clearly was no option.

      The underlying question for me is - does AI also internally work with just with 256 shades of grey in its gradients too?

      Or was there theoretically a way to pass smoother Vectors over to PS which in contrast to AI can save 16 bit Gradients?

      All I tried thus far (importing AI though Clipboard as Shape-Layers/Smart-Objects) yielded unusable results for what I'm after.

       

      I heavily doubt that such a workflow is possible, but I thought I should at least ask. Thanks for any input!

        • 1. Re: save AI patterns with >8bit/channel?
          polyxo Community Member

          Ok, i guess that counts as "not possible"

          But does anyone know what's going on under the hood? Does the vector engine in AI always work with a set of colours which equals an 8bit colour spectrum?

          Or does the originally higher colour-depth only get reduced to 8bit when rasterizing or placing the .ai as referenced Vectors in PS?

          • 2. Re: save AI patterns with >8bit/channel?
            Mylenium ACP/MVPs

            When you move stuff to other apps it ceases to be parametric and at that point any discussion about 8bit vs. 16bit becomes an unproductive theoretical/ academic one. The other apps would have to support such gradients natively rather then resorting to the AI/ PDF engine or pre-rasterized data stored in the file. That being so, you cannot expect to get a different result in PS than in AI, give or take color profile/ color space specific quantization differences. So to cut a long story short: No, you won't be able to get 16bit gradients in any form this way. The best you can hope for is to copy&paste paths to PS shape layers and construct your patterns there.

             

            Mylenium

            • 3. Re: save AI patterns with >8bit/channel?
              polyxo Community Member

              Wow, that's what I call a perfect invitation to post more here...

               

              My question had an absolutely practical background - nothing at all accademic in place.

              I believe you did not understand what I am actually after.

               

              Of course my main interest is getting patterns out of Illustrator in 16Bit, with perfectly smooth gradients.

              But I knew before even posting that this is not possible by writing images out of Illustrator directly.

               

              Therefore I and was looking for creative workarounds.

              Further I wanted to figure out whether AI's Vector-Engine at least internally fulfills the conditions to author maps of the kind shown in the link I provided.

               

              Besides your teacherque rant all you suggest is what I knew before.

              And you as Adobe Employée don't even smell that it might be a good idea to support the CG-market a bit better.

              Congrats.

              • 4. Re: save AI patterns with >8bit/channel?
                Larry G. Schneider MVP

                He's not an Adobe employee any more than the rest of us.

                • 5. Re: save AI patterns with >8bit/channel?
                  [Jongware] MVP

                  Illustrator does not *have* to "work with 8 or 16 bits internally". All it knows is what the start and end values are.

                   

                  I don't think any of the raster formats you can export can be set to 16 bits, so your only option is to transfer your artwork to software that can.

                   

                  Even if it's not possible to copy "native art" as 8 bits, you could try a smoothing filter in Photoshop.

                   

                  One can also turn the issue around: given that you import a reasonably smooth image into the 3D software you link to, it would not be unreasonable to expect that software to automatically enhance smoothness and prevent the visible terrace stepping.

                   

                  (JET is not an Adobe employee. I imagine Illustrator might have taken a few different turns with the latest versions if he was. :)

                  • 6. Re: save AI patterns with >8bit/channel?
                    polyxo Community Member

                    He's not an Adobe employee any more than the rest of us

                    Oh, then I got this MVP-thing wrong.

                    • 7. Re: save AI patterns with >8bit/channel?
                      polyxo Community Member

                      Illustrator does not *have* to "work with 8 or 16 bits internally". All it knows is what the start and end values are.

                      Well I basically wanted to know whether there is a fundamental difference in how AI and PS handle vectors.

                      Kind of odd that the Bitmap-Editor can handle cases the specialized Vector-Editor does not.

                      it would not be unreasonable to expect that software to automatically enhance smoothness and prevent the visible terrace stepping.

                      Smoothing always means loss of detail.

                      The images I linked to are just crude examples. Sculpting-Programs can harvest the most suble detail from high-bitdepth maps.

                      It would be painful to smear them with gaussian blur.

                       

                      Thanks guys, I guess I must stick to the Photoshop-route.

                      • 8. Re: save AI patterns with >8bit/channel?
                        emil emil Community Member

                        polyxo wrote:

                        ...Smoothing always means loss of detail...

                        And this is exactly what you want to achieve don't you? The artifacts in the 8 bit displacement were caused from the details of the sharp transition between the shading steps of the 8 bit file.

                         

                        In the example you gave with the link in your first post the smoothness of the 3D displacement map depends on the blurred black and white image of the number 8  and 16 shown first in that web page not on the checker pattern which is a texture on top of the displacement. You can create any texture pattern in 8 bit in Illustrator and when applied as a texture you will have no problem - it will not affect the displacement map. You need higher bit depth for the displacement map texture itself  and it also must be highly blurred image too as shown on that web page. So, the question in your particular example is how you are going to create that blurred 8 and 16 number in Illustrator? A raster program like Photoshop seems to be much more appropriate for this. You can still type or create the 8 and 16 numbers in Illustrator but you need to open them as 16 bit file and blur them in Photoshop and you will be fine.

                         

                        In order of this thread to make sense you have to show a particular example of what image you want to use as a displacement map and why you want to make it in Illustrator, otherwise it is just guessing about what's in your mind.

                        • 9. Re: save AI patterns with >8bit/channel?
                          polyxo Community Member

                          And this is exactly what you want to achieve don't you?

                          No. Not at all.

                          In that particular case as only some sort of blob is required indeed some smoothing would do the job.

                          Blur in that particular case would do a job which would make it undistiguishable for the eye from the additional tones of grey a16 bit-source would deliver.

                          Again - this is by chance as the map consists of a simple gradient the author created just in order to make a point. It is no actual work-file!

                           

                          Please don't let us get the discussion off track. In CG 16 and even 32 bit displacement are establishished for many years and perfect reasons.

                          Also it's quite obvious that this sort of consideration does not play a role in daily work you guys have to do.

                          That's cool but don't tell me that the whole 3D Industry does it wrong.

                          ...otherwise it is just guessing about what's in your mind.

                          I asked a very concise question. I did not pester you with workflow details because they would not tell anything to many of you.

                          But trust me 16 bit make sense, vectors as Source make sense. And wysiwyg-tiling makes sense too.

                          I would have loved to combine that stuff inside of Illustrator instead of doing the pattern manually and without realtime-preview with means of Photoshop.

                           

                          Anyway, I'm, out, cheers!

                          • 10. Re: save AI patterns with >8bit/channel?
                            polyxo Community Member

                            Ok - a bit milder after some sleep...

                             

                            On the displacement-image from post#1: Just imagine that there was another small 8 drawn on the highest point.

                            Its lowest point was the highest point of the larger 8. It was smaller overall but I still wished it to appear perfectly smooth.

                             

                            The problem however is that in 8bit one only had a small handful of tones available to interpret this smaller

                            graphic on the peak of the larger one. The graphic as a matter of fact is already close to white and one has to express yet another hill...

                            One simply runs out of colour-resolution and would end up with horrible stairstepping.

                            I think it's quite obvious too that smoothing was of no help whatsoever for solving this problem.

                             

                            Typical 3D-Software for such reasons can distinguish far far more tones than 256 in brightness between black and white and

                            (given the deformed geometry offers enough mesh-resolution) it can transfer those into a highly detailed relief.

                             

                            I realize that one can set up the base of a seamless pattern in AI and can send a hand-made tile of it over to PS

                            (as PS for no proper reason can not directly use the patterns AI makes...).

                            Inside PS one finally can apply smooth gradients but I can not call this a cool workflow at all.

                             

                            I just have a hard time with some typical forum phenomenons...

                            New posters always are assumed to not know what they are doing, pretty much regardless of how precise they can put forward their question.

                            If there's a problem in a pipeline to other products the case is clear: It's either user-error and if not, clearly the third party-program

                            has non adequate demands.

                            This is an observation which I do not only make here but in pretty much any Software-Forum.

                            It may make it hard to ask for advise at times - one always needs to discuss stuff one actually did not ask for.

                             

                            cheers!

                            • 11. Re: save AI patterns with >8bit/channel?
                              Wade_Zimmerman Community Member

                              If it is a practical matter why don't you create a 15 bit document in PS and place the ai file into it?

                               

                              I think you will find the gradient is smooth which it is if placed in an 8 bit as well.

                               

                              I think you will be able to visually judge by your screen and a proof. That way you will know whether it is a smooth gradient.

                               

                              And yes I know that does not answer your question even though it actually does if it is actually a practical matter.

                               

                              The answer is it doesn't matter what happens under the hood if it gets you where you have to be,

                              • 12. Re: save AI patterns with >8bit/channel?
                                emil emil Community Member

                                polyxo wrote:

                                 

                                And this is exactly what you want to achieve don't you?

                                No. Not at all.

                                In that particular case as only some sort of blob is required indeed some smoothing would do the job...

                                If you have a very hard edge, first it will never work well in a displacement map especially if you zoom in it because you will see the pixels forming hard edge polygons, and second the 16 vs 8 bit looses advantage because you don't have a transition that creates a smooth 3D displacement surface. For example if you have a grayscale image with bands of different gray steps you will create a staircase steps object with the displacement map. With a very hard edge it will be the texture's pixel density (size of each pixel on the 3D surface) that becomes most important but this approach is not desirable because first it will never be perfect and second increasing the image resolution just to fix hard edges will increase exponentially the rendering time. Look at your example again http://www.digitalartform.com/assets/8bit_full.jpg there is no terrace artifacts where you have completely black color on the grayscale map outside of the blob of the number 8. The staircase effect at the first transition between complete black and the next gray level has a jagged line that is caused by the size of the pixels of the displacement texture as mapped on the 3D surface. If you don't have any smooth transition between two colors then 16 vs 8 bit will loose its advantage.

                                polyxo wrote:

                                ...

                                Please don't let us get the discussion off track. In CG 16 and even 32 bit displacement are establishished for many years and perfect reasons.

                                Also it's quite obvious that this sort of consideration does not play a role in daily work you guys have to do.

                                That's cool but don't tell me that the whole 3D Industry does it wrong.

                                ...

                                No one is questioning the importance of 16 and 32 bit and no one is telling you that the 3D industry does it wrong, where did you see that? Quite the opposite, you do need higher bit depth and I would even recommend 32 float instead of 16 bit because it is just slightly better than 8 bit - it is still integer. However with displacement maps you will loose the advantage of the higher bit depth if you don't have blurred edges to create a smooth transition. It doesn't have to be a blob but even with sharp displacement map you have to have some small amount of blur on the edges which will create a bevel like effect to hide the pixelation if you zoom in on the 3D object.

                                Here I made a test creating a 3D displacement from this image in a 3D program:

                                 

                                This was 32 bit exr file and the edges of the letters as you see are completely sharp - click on the image to see full resolution

                                TestDisplacementTextSharp.jpg

                                 

                                and this is the rendered result - you can clearly see the artifacts from completely sharp edges on the letters

                                TestDisplacement32bit_TextSharp.jpg

                                 

                                This was the same 32 bit exr file but the edges of the letters are blurred a little - click on the image to see full resolution

                                TestDisplacementTextBlurred.jpg

                                 

                                and this is the rendered result - the blurred edges (loss of detail) avoids the artifacts and it looks nice

                                TestDisplacement32bit_TextBlurred.jpg

                                 

                                and this is a displacement rendering using the the same image with the blurred letters but converted to 8-bit targa file. This made the blob larger because of the gamma difference between linear 32 bit and non linear 8 bit but the point is that you can see the artifacts on the blob caused by the 8 bit but the edges of the letters look better than the sharp edges in 32 bit.

                                TestDisplacement8bit_TextBlurred.jpg

                                 

                                polyxo wrote:

                                ...

                                I asked a very concise question. I did not pester you with workflow details because they would not tell anything to many of you.

                                But trust me 16 bit make sense, Vectors as Source make sense. And wysiwyg-tiling makes sense too.

                                I would have loved to combine that stuff instead of doing the pattern manually with means of Photoshop.

                                ...

                                No, you didn't ask a very concise question. It would have been concise if you had posted the grayscale images you intend to use as a displacement texture map. Look again in the grayscale image of the number 8 and 16 from the link in your first post and also look at my grayscale images I posted above and tell me why would you want to create these images in Illustrator? Without showing us a specific image, your question about the relevance of using Illustrator for creating it cannot be concise.

                                • 13. Re: save AI patterns with >8bit/channel?
                                  polyxo Community Member

                                  Wade, I think I descibed quite clearly what I need. Just read it .

                                   

                                  Of course, before even posting I had already tested all options which came into my mind including placing .ai's with existing gradients into PS.

                                  Exported 16bit or 8bit tifs are absolutely unusable for my goals  - it's obvious that placed ai's come in with 256 shades of grey.

                                   

                                  Don't understand it as unfriendly but unless someone can contribute a route which actuall yallows for higher bitdepths

                                  I think we would just waste our time by going on here.

                                  • 14. Re: save AI patterns with >8bit/channel?
                                    emil emil Community Member

                                    Wade_Zimmerman wrote:

                                     

                                    If it is a practical matter why don't you create a 15 bit document in PS and place the ai file into it?

                                     

                                    I think you will find the gradient is smooth ...

                                    Wade, no, this will not work. If you create a gradient in Illustrator and paste it in a 16 or 32 bit image in Photoshop or open the .AI file as a 16 bit file in Photoshop the gradient will not get smoother than the 8 bit file. You can measure this with the eyedropper in Photoshop when set to measure 16 bit in the Info panel. The jumps between the adjacent shades will be pretty drastic in comparison to a gradient created in Photoshop in 16 or 32 bit document.

                                    • 15. Re: save AI patterns with >8bit/channel?
                                      polyxo Community Member

                                      @ emil emil.

                                      Thanks for your tests. I however don't know what to answer now....

                                      It's obvious that you understood my need.

                                      Yeah, do not deny that subtle (high bitdepth) smoothing makes sense for harsh transitions.

                                       

                                      But this leads off track...this discussion was not about finetuning of already goodlooking displacement

                                      but about allowing Illustrator to produce something half way decent to begin with.

                                       

                                      All you show what looks good is not doable in Illustrator...

                                       

                                      I still think that I presented my problem in an understandable way.

                                      It was not my goal to educate people but to maybe get a hint for a workflow inside of AI which allows for >8 bit I did not think of myself.

                                      • 16. Re: save AI patterns with >8bit/channel?
                                        emil emil Community Member

                                        Unfortunately no, you can't create completely in Illustrator grayscale images for smooth displacement. You can still create hard edge patterns in Illustrator but you have to blur their edges in 16 or 32 bit file in Photoshop and also add there any smooth elements.

                                        Photoshop also has nice seamless pattern texture creation (from the 3D menu > New Tile Painting), have you tried that?

                                        • 17. Re: save AI patterns with >8bit/channel?
                                          polyxo Community Member

                                          Photoshop also has nice seamless pattern texture creation (from the 3D menu > New Tile Painting), have you tried that?

                                          For my needs the 3D-toolset in PS-Extended did not justify the extra cost. So that's no option here.

                                          Apart from that I really would like to use editable vector-approaches in cases where such made sense.

                                          • 18. Re: save AI patterns with >8bit/channel?
                                            emil emil Community Member

                                            May be you know it but the Offset from Filters > Others will cut any image so its borders are seamless but you have to take care of the seams that that will be moved inside the image. Not as sophisticated as the Tile Painting but nevertheless will turn any image with seamless boarders that can be used as a pattern.