Opacity bug on attached canvas

[Anonymous]

This might have been reported before, but I couldn't find the issue.

When I use "attached canvas" and have a body on top of it, then setting the opacity of the body anything <100% does not draw correctly.

Left:Opacity of green cylinder: 90%  Right:Opacity of green cylinder: 100%

See attached screencast.

[ahreum.ryu]

Hi @Anonymous, 

Thank you for reporting this issue. 

I tried to reproduce your issue but I was unable to do it. Could you take a look at my steps? Is there something I miss? 

Could you share your design? Here's how to share it.

May I know your OS? 

I look forward to your reply

Many thanks, 

Ahreum. 

[Anonymous]

@Hi @ahreum.ryu,

thanks for your reply. As far as I've seen, your steps match mine, the only difference being that you have selected the "Shaded with Edges" display option enabled, where I only have "Shaded", which gives you the black border lines.

Having said that, I think your video also displays the bug, actually. To clarify: When I set an object to 90% opacity, I do not expect it to become basically invisible (that would be 0%) and only show me the edges. I would expect it to be visually like a rather dense glas-object. It also works like that for other objects (that's why my test had the second cylinder on a plane to demonstrate.), but it does not for canvases.

To clarify, this would be the model:

Strangely, I don't see the figure captions in my post (but I see them when I edit), so from left to right: 

Model at 100% opacity, 50% opacity, 50% opacity with "shade only" and finally, the "expected" display (a fake image made with Powerpoint)

I don't think my model would help, but here it is anyway:  http://a360.co/2fUnmWf

[Phil.E · Accepted solution]

Hi,

Thanks for posting.

This does seem like a bug I can check up on, which I will do.

In the mean time, there are 3 controls that are affecting the situation. You are only using one, component opacity.

The other two are in the Edit Canvas dialog (or new Attached Canvas).

First there is Display Through.

• When this is ON, the canvas will display through anything that is between it and you.
• Components are transparent when canvas is behind them.

Second is Canvas Opacity.

When this is less than 100%:

• Objects behind the canvas will show through.
• Transparent bodies in front of the canvas can be seen.

To have a see-thru canvas, sort of like in the 4th image:

1. Go to edit Canvas, turn on Display Through. Your component does not need to be transparent at all.

2. Or, go to edit Canvas, set Canvas Opacity to <100%. Your component can be transparent or not, but the canvas will not block view of it.

Please let me know if you have questions.

Regards,

[Anonymous]

Thanks @Phil.E

If I understand you right, then the "bug" is that once "Display Through" is not enabled, the software currently behaves as if it would, but using a "overlaying object opacity of 0%" instead of the objects real opacity setting. Hence the overlaying object "disappears".

[Phil.E]

Yes. Basically, either object, if one is at 100% and the other is <100%, the "loudest" one wins, the 100% will cover the other. In the case of an object sitting on a canvas, it is confusing to lose the view of the object, as if the canvas is "on top" of it. I tend to never dim any model body, and instead use canvas display through to manage it. 

Note: with Display Through turned ON, the model bodies can be at any opacity and still be seen correctly.

[amxfmx]

I use Display Through when I sketch and that work, but when I zoom (or the line is too long) the line disaper, I can see it from the other side only (so my canvas become inversed).

 English is not my main language so I hope my wording is clear.

[Phil.E]

@amxfmx

Got it. If you use only "display through" you can get what your image shows.

I recommend to use display through and also <100% canvas opacity. The sketch lines will show through in any case. Please let me know if you have questions.

Regards,

[Phil.E]

@Anonymous

A change has been made to include by default: 50% opacity for canvas, and Display Through is turned on. It's not clear when this can be released, probably in an update some time in November or later.

Thanks,

[Timothy.McIntyre]

Any update on this bug?

Setting the top component to anything less than Opacity=99%, and the bottom component with canvas is not affected, whereas other solid components are correctly visible.

If I set the canvas'd component to Display Through it then becomes transparent, which is not what I want in a solid component with a canvas top and bottom face.

[Phil.E]

Canvas is not really intended to be a graphic on a component. Have you tried using Decal instead? A canvas is geared to be a drawing aid, one you can insert and calibrate on a plane to use in sketching. I may be misunderstanding you but it sounds like you are using canvases as decals.

[Anonymous]

Ah, I see. Will apply a decal in the future.

Thanks for the update.

[Phil.E]

Please let me know what you find. I want to make sure decal does what you need it to do.