withAlpha not working in sandcastle demo (nor in my code)

CesiumJS
1

1. A concise explanation of the problem you’re experiencing.

In my code and in the polygon sandcastle tutorial, any polygon that has a withAlpha transparency setting is not being displayed at all

2. This is straight from the sandcastle demo

This Displays Fine

var orangePolygon = viewer.entities.add({

name : ‘Orange polygon with per-position heights and outline’,

polygon : {

hierarchy : Cesium.Cartesian3.fromDegreesArrayHeights([-108.0, 25.0, 100000,

-100.0, 25.0, 100000,

-100.0, 30.0, 100000,

-108.0, 30.0, 300000]),

extrudedHeight: 0,

perPositionHeight : true,

material : Cesium.Color.ORANGE,

outline : true,

outlineColor : Cesium.Color.BLACK

This Doesn’t

var orangePolygon = viewer.entities.add({

name : ‘Orange polygon with per-position heights and outline’,

polygon : {

hierarchy : Cesium.Cartesian3.fromDegreesArrayHeights([-108.0, 25.0, 100000,

-100.0, 25.0, 100000,

-100.0, 30.0, 100000,

-108.0, 30.0, 300000]),

extrudedHeight: 0,

perPositionHeight : true,

material : Cesium.Color.ORANGE.withAlpha(0.5),

outline : true,

outlineColor : Cesium.Color.BLACK

}

4. The Cesium version you’re using, your operating system and browser.

My code worked fine in two weeks ago so perhaps an issue with the latest release? Are others having this issue? I’m running on win 7 in Chrome.

2

Can you test this Sandcastle:

Do you see a green cylinder on the right? Then test the same Sandcastle in 1.56:

https://cesiumjs.org/releases/1.56/Apps/Sandcastle/index.html?src=Cylinders%20and%20Cones.html

Do you see a green cylinder on the right?

If the answer is no to both, then this might be an issue with the version of Chrome. There’s some more details on this issue here: https://github.com/AnalyticalGraphicsInc/cesium/issues/7798

Can you tell me what Chrome version you’re using? And what graphics card you have?

3

Thanks for the links, very helpful. For me the issue is with polygons and cylinders…and possibly other shapes i haven’t tested. The odd thing is i didn’t change a thing about my setup and all of a sudden it stopped working.

That said, I’ve isolated the issue to chrome (win 7). I started having the issue with Chrome 74.3729.108 and updated to 74.3729.131 (latest) but still had the issue. Note that I’m running chrome on a mac via the latest version of parallels. I see the red triangle, but only the frame outline of the cylinder. I tried attaching a picture. I used the withAlpha functionality last on April 23 in sandcastle with chrome (win) …108 and it worked fine.

I didn’t think it possible but both links worked fine with IE, Safari, and the Chrome (v …131) for mac (10.14.3).

I have a standard issue mid-2014 MacBook Pro (Intel Iris 1536 MB)

alphaTest.JPG

4

Thanks for helping us isolate this to Chrome! Just to confirm, you’re seeing NO translucent green in both of the Sandcastle links I posted in Chrome, but you DO see green in both sandcastle links in other browsers?

5

I can confirm the additional behavior from the GitHub issue 7798

A user with a Dell Windows 7 non-touchscreen laptop is seeing no fills on any kind of polygon in the Sandcastle demos, beginning with Chrome 74 and including beta 75. Firefox works normally.

6

correct. And to be clear wrt chrome, i see no green in chrome for windows. I do see green in chrome for mac.

7

oh and it’s also happening with my polylines that have a glow property

8

Looks like it was a Chrome issue after all, and it should be fixed with the next version of Chrome. See: https://github.com/AnalyticalGraphicsInc/cesium/issues/7798#issuecomment-501556152