Transparent background screencap - edges also transparent?

Hmm, in my shaded mode I have edge color reduction on (50%). When I do a ViewCaptureToFile, I get the edges going transparent… Also if I have a ClippingPlane with edges on, those go transparent too.

Rhino VP:


What happens if your edge color is not 50% transparent?
Is it any different if they are 0% or 40%?

Transparency degree appears to follow the color reduction percent.

0 color reduction=no transparency
10 color reduction=very slight transparency

50 color reduction=partial transparency

100 color reduction=complete transparency

So does diddling the edge transparency in Rhino have any effect on what you get in Photoshop?

Yes, as I said, it’s directly proportional. Only way to have 0 transparency is to set reduction to 0. Then the problem becomes that it is only possible to have the edges either the object’s color or a single fixed color for all objects in the file.

The nice thing about the color reduction is that it gives you an edge color that is darker than the object color, but still related to it.

Sorry, that wasn’t clear to me in your reply.
It does suggest a work-around; to set the edge color to an opaque color that is a little darker than the surface color.

Yep. But if you have a dozen different object colors, that’s painful.

I can’t tell if this is a problem with Rhino or a problem with Photoshop.
Clearly, it’s an annoyance to you.

We’ll see what @stevebaer has to say about it when he returns.

Bugify it please JB.

Mitch, what does photoshop look like if you changed the background in photoshop from checkerboard to the dark gray that you were using in Rhino?

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Like this (50% edge color reduction):

Which is what is expected, it takes on the background color.

Unfortunately, the goal of having a transparent image background was to drop the object out against a white background…

If the background is white, it looks like this:

Red is more fun…

I can understand the goal, I was just interested in seeing what those pixels looked like since I was not expecting them to have alpha based on how colors are blended in OpenGL. Thanks Mitch


Hi Mitch,

Are you capturing to file using the “Transparent Background” option? Or does any capture to file yield transparent edges?

What are your exact steps? I’ve tried this in both V6 and V7, and I get the expected results in all cases (I’ve tried).


Hi Jeff,

Yep, transparent background checked.

Just call the command, the dialog comes up, leave it at viewport resolution, just the transparent background checked and save as .png…



Ya, that’s what I’m doing…and I have my edge reduction set to 50% … What does your capture dialog show? Are the wires transparent there too?

Here’s what I see…

Here’s what I see… Yes, the edges are transparent in the preview already…

My background is gray 70,70,70.

Weird… What’s your exact version of Rhino?


Version 6 SR23
(6.23.20049.14121, 18-Feb-20)

Edge color reduction 50%

Thanks, I just installed that version here and I’m still not seeing this…

Can you please export your Shaded mode and post the .ini file here, along with your simple .3dm file (I know it’s just a box, but I want be using exactly what you’re using at this point)… also, post the resulting .png file you get…just so that I have it to compare my results against.

Note: Do not Restore your display mode(s) yet…if it’s something related to a mode setting, I don’t want to lose that.


Here ya go…

JeffsCube.3dm (337.1 KB)
Shaded.ini (11.9 KB)

As I said, viewport background 70 gray, but I don’t think it actually matters in this case.