PNG export with alpha channel for transparency

[Kaare Baekgaard]

I often have to use Vectorworks renderings for photo manipulation.

Every time I have to use valuable time and effort to isolate the objects, that I need, from the white background.

I can export PNG's of textures with perfectly good alpha channels. So why can I not do the same with my renderings?

I wish, there was an option to get transparent backgrounds in exported PNG's - and that it was sophisticated enough to get semitransparent alpha-transparency from semitransparent objects.

I am pretty sure, that users of Panzercads Cameramatch would be very pleased with this feature as well.

Edited June 27, 2015 by Kaare Baekgaard

[Benson Shaw]

+1

-B

[PVA - Admin]

Agreed! Submitting request now.

[creiglee]

PNGs create transparency in one of two ways. One of these methods employs the same approach used by GIFs, with a single color defined as transparent, and the other is to set an alpha channel . One of the advantages of PNG single-color transparency is that it doesn't remove a color from the available palette. However, the alpha channel is a much smoother method, as it is far better at blending colors, and allows you to select different levels of transparency in specific regions. The transparent areas of the PNG will blend and adjust naturally to whatever is behind the image when the background of the page isn't a solid white or black color.

[htranbos]

Hi,

 

I export a png rendering from Vectorworks 2023 with a transparent alpha channel.

 

When I open it in photoshop and place it over a black gradient background. I can see jagged edges around the image.

 

Does anyone know how to fix this? Thanks

[mjm]

@htranbos Sheet layer viewport or design layer? If Sheet Layer VP, make sure your Sheet DPI is set high enough for publishing - I often use 300 DPI.

Edited Tuesday at 11:12 PM by mjm

[htranbos]

Design layer and it is set to 300 DPI. I zoomed in for the screenshot so you can see the jagged edges. 

[mjm]

I sometimes go to 600dpi not that I want to but…

[Jeff Prince]

5 hours ago, htranbos said:

When I open it in photoshop and place it over a black gradient background. I can see jagged edges around the image.

 

Does anyone know how to fix this?

 

You aren't going to eliminate it in Vectorworks, but as @mjm mentions, increased resolution can help diminish it.

 

The correct way to fix it is to edit the Alpha/Layer Mask inside Photoshop.  This will preserve the quality of your image while allowing you to change how the edge of the mask looks.  Lots of tutorials on Youtube I imagine.  This is a common thing and a skill that should be learned if you compose boards and do a lot of raster work.  It's especially helpful if you make your own image props or fix the ones that came with VWX.

[grant_PD]

there is a defringe and matting tool in photoshop, you can specify how many pixels of "fringe" you want to cut off.  

 

Doesn't let vw off the hook for not providing alpha transparency export tho.  

[Jeff Prince]

2 hours ago, grant_PD said:

Doesn't let vw off the hook for not providing alpha transparency export tho.

 

Vectorworks does export the alpha channel though...

[grant_PD]

@Jeff Prince It does support an alpha channel.

But what it doesn't have is the object buffer system like C4D.  Where you can render out multiple alpha channels for different objects.  When I speak of alpha transparency export, that's what I am referring to.  So to @Kaare Baekgaard's point, I read that as what he is wanting.  

[Jeff Prince]

42 minutes ago, grant_PD said:

So to @Kaare Baekgaard's point, I read that as what he is wanting. 

 

His post is nearly 9 years old, perhaps things have improved a little? 

@htranbos necromanced this thread and had a different concern.

 

I don't know how C4D does things, but Vectorworks has a rudimentary stacking of transparency that actually exports pretty good, see video.

What would be nice is to have by object and z-buffer exporting, but I can't fault VWX for not having those given it's purpose and audience.

 

 

 

[grant_PD]

LOL love the playlist!  

Agree, Vw has come a long way in those 9 yrs.  I just don't want them to rest on their laurels here.