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PDF exporting with inconsistent lighting.


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Croweyes1121

I have an object with transparency and lighting effects.  When I try and plot it to PDF, the results seem to subtly change every single time I create a file, even if I haven’t changed anything in the dwg.  I can provide images if necessary.  It seems to vary based on which PDF printer driver I use, whether I’ve just restarted the program or not, etc.  but it also can vary based on seemingly nothing - I can create two PDF’s back to back, and they’ll wind up with different parts of the image with more transparency, others with less.  Is this normal behavior, and is there any way to get more consistency?

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Cad64
14 hours ago, Croweyes1121 said:

I can provide images if necessary.

Yes, it would be helpful to see what you're printing and the different results you're getting.

 

Using different printer drivers can affect the look of the printed output, so try to stick with just one printer driver for consistency. Beyond that, I don't know why you would get different results randomly when printing using the same driver.

 

Is there a reason why you're printing to pdf instead of rendering?

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Croweyes1121
Posted (edited)
On 6/23/2021 at 10:25 AM, Cad64 said:

Yes, it would be helpful to see what you're printing and the different results you're getting.

 

Using different printer drivers can affect the look of the printed output, so try to stick with just one printer driver for consistency. Beyond that, I don't know why you would get different results randomly when printing using the same driver.

 

Is there a reason why you're printing to pdf instead of rendering?

You may have to toggle between these two to see what I mean.  Notice how the inner portion of the R (the blue streak part) is dimmer in the first image and brighter in second.  The top streak on the right portion of the M is brighter in the first, then dimmer in the second.  I know this may seem like nitpicking, but I'm doing a frame-by-frame animation, and this jumping around of the lighting looks horrible in motion.  I'm keeping the angle from the light sources absolutely consistent, so it's not the position of the letters or streaks that's doing it. 

 

Would rendering be a better option?  It takes absolutely forever compared to printing to PDF.

Super-11.png

Super-12.png

Edited by Croweyes1121
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Cad64
18 hours ago, Croweyes1121 said:

I know this may seem like nitpicking, but I'm doing a frame-by-frame animation, and this jumping around of the lighting looks horrible in motion.  I'm keeping the angle from the light sources absolutely consistent, so it's not the position of the letters or streaks that's doing it. 

 

Would rendering be a better option?  It takes absolutely forever compared to printing to PDF.

 

No, it's not nitpicking. If you're doing an animation then you need your lighting and everything to be consistent. Rendering would certainly provide the consistency that you're looking for, but in all honesty, I would not use Autocad for this. I would use a program that's better suited for this sort of thing. Have you looked at Blender? It's a free 3D modeling/animation program  that you could use to render out the full animation to video instead of printing each frame, one at a time and then stitching all the images together. And yes, rendering does take longer because the program is calculating the light bounces off all the surfaces, and that takes some time, but the result is much cleaner and higher quality than printing to pdf.

 

Here's another question. In Autocad, have you set up a camera for viewing the text or are you simply printing a pdf based on your current view in model space or a paper space viewport? I feel like you might have better luck printing from a camera view, but that's just a guess.

 

By the way, how are you printing to pdf with a black background? I've never tried doing this before and I'm not having any luck achieving this.

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Croweyes1121
Posted (edited)

When I try and render, I get a very odd result.  I “see” the light sources I’ve set up (meaning, I see huge orbs of light, which totally throws off the color in the final product).  It almost looks like a negative when it’s done rendering.  I don’t know what I’m doing wrong there.

 

I have no experience with Blender and was hoping not to have to learn another program to do this…but it may be necessary.

 

Yes, I’m just printing my current view in modelspace, I haven’t set up a camera.  I’ve actually never done that and didn’t know it was an option.  I’ll have to look into that.

 

To get a black background, I just changed my modelspace background to something other than black, then made a rectangle (underneath my drawing along the Z axis) hatched with black.  Works pretty well.

Edited by Croweyes1121
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Cad64

Try setting up a camera and make sure your light sources are outside the field of view, so you don't see them. When rendering, the output will look different because Autocad is calculating the light intensity, photons, bounced light, etc. So it's different than simply printing what you see in model space. You might need to adjust your lights to get the same look when rendering.

 

As for the black background, yes, your description is what I found when looking online. I was looking for a print background color option within Autocad, but it doesn't look like there is one, so the workaround with the hatch is the only option for printing, I guess?

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  • 1 month later...
Croweyes1121

I absolutely cannot get render to give me results that look good.  It comes out looking like a cartoon with simplified lighting every time.  Not remotely what I’m after.  This is incredibly frustrating as AutoCAD would work PERFECTLY for this project IF I could get it to PDF two images with the same lighting.  It changes it every time.  I’ve been trying to fix this since my initial post, and still no luck.  :(

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BIGAL

I have done a few very simple animations the best was walking up a spiral staircase looking at  a house in full 3d. Using simple shade not a render image.

 

Have a look at this may be useful link to animation. May not be of use. 


https://knowledge.autodesk.com/support/autocad/learn-explore/caas/CloudHelp/cloudhelp/2018/ENU/AutoCAD-Core/files/GUID-19E41C48-90E0-4462-9CC3-1BBBECFF5CC1-htm.html
 

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Croweyes1121
Posted (edited)
On 8/11/2021 at 9:18 PM, BIGAL said:

I have done a few very simple animations the best was walking up a spiral staircase looking at  a house in full 3d. Using simple shade not a render image.

 

Have a look at this may be useful link to animation. May not be of use. 


https://knowledge.autodesk.com/support/autocad/learn-explore/caas/CloudHelp/cloudhelp/2018/ENU/AutoCAD-Core/files/GUID-19E41C48-90E0-4462-9CC3-1BBBECFF5CC1-htm.html
 

Thanks, but no, this will not help.  The 3D streaks themselves need to move, not just the camera.  Take a look at the examples attached here.  All I did was surftrim the 3D streaks along a plane that's parallel with the view.  Any time I make any change to the streaks at all, the lighting changes entirely, so it bounces around every frame when I try and show the progression in motion.

CE25.png

CE24.png

What I need is for the lighting to be consistent from frame to frame instead of bouncing around at random.  I've tried changing the reflectivity of the clear blue glass material (on direct and oblique angles) to matching values - no effect.  No matter what I do, the lighting changes every time.  Very frustrating.  Is there no way to get CONSISTENT lighting?  I've tried exporting to PDF and to PNG (the latter alleviates the banding issue that seems to come with PDF export, but the lighting inconsistency problem remains).

Edited by Croweyes1121
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Croweyes1121
40 minutes ago, BIGAL said:

Understand as Cad64 said "I would not use Autocad for this" 

I’m aware that After Effects or Blender is evidently the preferred method, but AutoCAD is what I know, so I was hopeful that there was some workaround for this lighting inconsistency bug rather than having to learn an entirely new piece of software.

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