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Light shining through objects

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Hello all,

I have modeled a light fixture approximate to a real one.

I created the shade using 360º polygon sweep and inserted a point light.

As you can see, the light casts it's shadows downward OK but also strangely upward thru the top of the sweep where the mounting rods and upper housing DO create shadows.  The side of the shade casts a shadow but not the top of the shade.

How can I model this correctly so the shade actually blocks all the light except for through the lower open portion of the shade?

Thanks

Bradley

 

1428222684_ScreenShot2018-08-15at7_44_59PM.thumb.png.febcf92a174d5848c93a5e6f536d304d.png

1671934457_ScreenShot2018-08-15at7_48_52PM.thumb.png.61c384fd017e7d769a88122d48d26d45.png

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Posted (edited)

Interestingly, there is a solid disc in the upper housing (shown highlighted in first shot) that is casting shadows as shown by when it is deleted the upper wall shadow is just showing the ring shadows (shown in second shot).  Yet when I move it down to the top of the shade, it doesn't block any of the light from there (third shot).

1075364572_ScreenShot2018-08-15at8_25_14PM.thumb.png.9ad402bd422848c5b8bde4b122a27e8f.png1231122325_ScreenShot2018-08-15at8_27_19PM.thumb.png.58ea190307312e2982e85e8b66febf32.png111121855_ScreenShot2018-08-15at8_26_47PM.thumb.png.ba79c6a0f9f86f04770c1723736440ac.png.

Edited by bc
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Is your point light far away enough from the geometry?

Possible workaround: Add another solid over your light source to prevent any shadows over the fixture.

That second posts' third pic is confusing though: Is the highlighted solid blocking any shadows if you try it on its own?

Maybe you have to reposition the light source further down...Want to include the file?

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Is the 2D Polygon that created the sweep a closed shape? I've had problems with sweeps if that's not the case.

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Well it seems like his sweep (only the bottom part of the shade I believe) casts shadows correctly. It is the top part of the object that doesn't work, right? And if that is also a sweep, then you might have to check if it is a solid. (eg. the 2D Poly a closed shape)

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1 hour ago, Jan-Burger TROOST said:

Dit you try another render method than OpenGL? I found OpenGL had light shining even through walls…

 

That did it Jan-Burger and it sucks that that is the case.

What is happening with OpenGl anyway?  Never had this happen and never thought THIS would be a wishlist item.

Problem solved......sort of.  It seems now I can't get there from here....lest I RW.

Thank you all for your suggestions. This is rather dumbfounding.

Bradley

 

Maybe there's a preference somewhere????

Such as:   "Don't transmit light through solid opaque objects".   Sheesh. Who would have thought?

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In open GL options there is a use shadows, and another check box for ground only.  Also a level of shadow checkbox.  check that out.

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5 minutes ago, Rob Books said:

In open GL options there is a use shadows, and another check box for ground only.  Also a level of shadow checkbox.  check that out.

Thanks for that Rob but no joy.

Interestingly, with or without shadows checked, I am now getting this strange rectangular artifact?

Maybe I need to just rebuild this light in a new file?

1963194156_ScreenShot2018-08-16at6_35_03AM.thumb.png.48a322f4f3cd5e0ecd33546d370a801f.png

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Any chance you could post a file with the light fitting ?

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Posted (edited)
12 minutes ago, markdd said:

Any chance you could post a file with the light fitting ?

HERE'S THE WALL WITH SYMBOL AND WITHOUT BATTENS. THANKS

 

LAMP TESTY.vwx

Edited by bc

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Same result here after trying various things - pasting into a clean file, rebuilding parts of the geometry, replacing the light etc.. I think you should bug submit the file (link in the footer below). I don't think its behaving as it should, especially given that it has a "plate" at the top of the curved shade. Even in Renderworks the fin detail shouldn't be casting shadows.

 

Kevin

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45 minutes ago, Gadzooks said:

What effect are you after bc?

 

656322154_ScreenShot2018-08-16at15_25_01.thumb.png.e9394f3b4190385bf97f15396431ae4d.png

NOT THIS EFFECT.

I just want the light to shine down from the shade as it would in real life rendered in OpenGL.  See RW render attached.  I want the light to perform like this in OpenGL.

1512777083_ScreenShot2018-08-16at6_13_35AM.thumb.png.e545f4f29764086f86b0282113207134.png

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38 minutes ago, Kevin McAllister said:

Same result here after trying various things - pasting into a clean file, rebuilding parts of the geometry, replacing the light etc.. I think you should bug submit the file (link in the footer below). I don't think its behaving as it should, especially given that it has a "plate" at the top of the curved shade. Even in Renderworks the fin detail shouldn't be casting shadows.

 

Kevin

Thanks for you time in corroboration,  Kevin.  I'll try a bug submit.

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This is absolutely a bug, but I have no idea what could be causing it. I boiled it down to simply the flared shroud sweep object and the light, and the shadow is still incorrect, regardless of the texture applied to the shroud, so it isn't a cast/receive shadows thing. Same thing with a new light object. Same thing if i extract the faces of the sweep and build a replacement out of nurbs surfaces, its almost as if the shape alone baffles openGLs shadow calculations. 

The other thing that makes me think bug, is that in Renderworks it behaves exactly as I would expect, and that while openGLs light calculation is much more primitive than Renderworks, this is certainly something that openGL should be capable of.

Definitely submit a bug, ill chime in on it.

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If you make the light sources visible you can see that the sweep (shade) does block the light correctly, only when the light source is moved too far up it shows through the sweep. As if the "point light" were the scematic light bulb used to show the light source.

Maybe in OpenGL the light source is computed not with the single point light in mind, but rather using the scematic bulb...

Its weird and doesn't make sense.

Low light.jpg

mid light.jpg

hi light.jpg

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I did file a bug JimW thanks for chiming in.

Yes Alt+F4.   When the light is no longer within the shade, it casts shadows properly.

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The workaround, such that it is, is to make the light source a Spot and change the beam angle to 180°

 

 

1896844702_ScreenShot2018-08-16at17_13_36.thumb.png.d4387d4c53b1fa850a1707a1695ce98c.png

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40 minutes ago, Jim Wilson said:

This is absolutely a bug, but I have no idea what could be causing it. I boiled it down to simply the flared shroud sweep object and the light, and the shadow is still incorrect, regardless of the texture applied to the shroud, so it isn't a cast/receive shadows thing. Same thing with a new light object. Same thing if i extract the faces of the sweep and build a replacement out of nurbs surfaces, its almost as if the shape alone baffles openGLs shadow calculations. 

Yes, I tried a Shell and a Solid Addition too.

 

41 minutes ago, Jim Wilson said:

The other thing that makes me think bug, is that in Renderworks it behaves exactly as I would expect

I'm not entirely sure it renders correctly in Renderworks. Here's a screen shot from my testing. The lower shade has a cap on it so there shouldn't be any light coming through the fins above it.

 

318609411_ScreenShot2018-08-16at9_12_59AM.thumb.png.a7d42629c9816f788b211f3904226413.png

 

Kevin

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1 minute ago, Kevin McAllister said:

I'm not entirely sure it renders correctly in Renderworks. Here's a screen shot from my testing. The lower shade has a cap on it so there shouldn't be any light coming through the fins above it.

 

Oh I hadn't testing RW with the original, just after I striopped everything but the flared shroud. That screenshot looks close but yeah, not perfect. I'll test that too and see if its a geometry bug or a opengl bug.

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1 hour ago, markdd said:

The workaround, such that it is, is to make the light source a Spot and change the beam angle to 180°

 

 

1896844702_ScreenShot2018-08-16at17_13_36.thumb.png.d4387d4c53b1fa850a1707a1695ce98c.png

Yes, thanks I did go there with ;less than 180 but it's not as good.

@Kevin:  Hmmmmm.  My Fast and Final and Custom RW all seem to work OK.

Could it beeeeee..........................................SATAN?!

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