Rendering bright dots

[bo]

Hi!

I'm having problems with rendering in AutoCAD.

As the picture becomes better during rendering bright dots appears:

I have no problem with the Picture being grainy but these, in this case red/pink, bright dots ruins the picture.

Working on the latest Macbook Pro laptop using materials that comes with AutoCAD, with the following presets:

1920x1080, 10 levels of rendering and high render accuracy

They always appear though, no matter the settings. But higher quality generates more dots that's also more visible.

Any ideas?

[Alfred.NESWADBA]

Hi,

rendering is a complex set of a lot of parameters. It depends on so many details that without having the option to try/to play with your settings guessing does not make sense.

Can you upload the drawing?

Can you please let us know which version of AutoCAD you are working with? In case of AutoCAD 2016 please let us know your setting of RENDERENGINE.

- alfred -

[bo]

Thank you for replying. I'd prefer not to upload the dwg at this time though.

I'm using AutoCAD 2017.

Is this kind of artefact common? Are there maybe some common mistakes beginners often make that results in weird stuff like this?

I guess I need to read up on AutoCAD rendering, any recommendations?

[Alfred.NESWADBA]

Hi,

>> Is this kind of artefact common

No, that's why I asked for the drawing, otherwise I would have answered it directly.

- alfred -

[gotphish001]

http://forums.cgarchitect.com/28616-white-dots-my-vray-rendering-help-3.html 

Seems like this thread is about your problem. I haven't used render much in AC, but seems like the solutions to this problem are similar in a variety of software.

[john.vellek]

Hi @bo,

Alfred is correct that finding the setting that is causing this can sometimes be complicated. Is it possible to attach just a portion of your file or a sample file that shows this behavior?

Is it also possible to provide a "final" render with the spots highlighted? I want to make sure that I am looking at the correct ones.

[john.vellek]

Hi @bo,

Have you gotten this to work properly? If not, please attach a sample file so I can take a look.

[bo]

Click to enlarge and you'll see these dots all over.

I attached the file.

Thank you!

[john.vellek · Accepted solution]

HI @bo,

If you change your light fixture so that it does not have the holes pierced in it then the dots will go away.

Please select the Accept as Solution button if my post solves your issue or answers your question.

[dgorsman]

Oh, yeah... when you put a light *inside* a fixture like that you can get all sorts of weirdness, even beyond what you would expect from cut-outs or transparencies, even with a simple inverted cone.  In cases like this stop thinking "real world" and start thinking more "end result" - adjust general lighting to suit what the overall effect would be.

Also, for high quality images 10 levels/passes is not sufficient - you should be running at least 20.

[Alfred.NESWADBA]

Hi,

>> stop thinking "real world" and start thinking more "end result"

A great statement 😉

- alfred -

[dgorsman]

I've delved into animation in the past, and it's served me well.  One of the common problems coming from the technical design side is continuing to look at things that way when doing visualization.  Produced images whether rendered stills, animation, or composites can usually be done better and faster by cheating on things like lighting (a couple of omni-directional lights instead of multiple fixtures) and texturing (wire mesh or chain-link fencing is a common one).

[bo]

Thank you! It still confuses me that I have had this rendering problem many times before without this kind of object in the file. But in this instance I'll just have to accept that my lamp is to complex for AC to handle 🙂