OTOY Forums

Hey, I'm trying to do a simple render only light just won't seem to pass through the windows. I even put a mesh light on the other side of the glass, and it won't light up anything inside the room. I'm using the latest plug in, and I used stock 'glass' for the windows. I can see outside the room just fine, and from an aerial perspective, I know the corner of the room should be well lit.

What happens if you delete the windows?

DrHemulen wrote:What happens if you delete the windows?

I'm not sure what you mean. Its a material of many for the shell of the room.

Oh ok, I thought the glass was a separate object. What if you apply a basic shader with opacity 0 or a portal set to off? Just to check if it is the light setup or your glass material?

Off the top of my head, you may also want to verify your kernel settings. The numbers next to the depths (specular, glossy, and diffuse) have a significant impact on how much light shows up, and how many "bounces" it is allowed to make. For my quick previews, I have all but specular set to 2, and for even previewing things with transparency effects, I find things can be stubbornly opaque until each is around 5 or so, depending on scene/material/lighting complexity. That applies even on something simple like the glasses on the character render I posted recently in the main sticky thread (page 20, I think). Granted, that's with the direct lighting kernel, but the principle applies to some degree for all of them, and I'm unsure which you are using.

For that one image in particular, if I left the depths at 4, the light would pass through the window, and reflect properly off of the water, show the stuff under the water appropriately, and then hit the glasses (again, showing proper reflection) and stop. Since there are two supplementary lights in front of the character, I'm not sure why those rays didn't pass through, but nothing went through the glasses until I bumped the depths up to 5. I still had to turn down the opacity of the lenses material a bit, but I think the last part is because I am using the direct lighting kernel, because it's not really as "smart" about path-tracing through materials as the others that are designed for it (somewhat logically, lol).

Edit: Also, you can try turning on/off the importance setting at the bottom of the Environments tab. Sometimes results are better one way or the other when dealing with interior lighting in particular. Also, from what I remember in the one thread I used to be able to find on portals, they only work in open slots, and anything being in the "window" negates them entirely, but I'm struggling to find that thread (which is old) or any new info on them, so take it with a grain of salt.

So I had loaded the standard glass, and light just wasn't going through by default.

I reloaded the default material, which was diffuse, and opacity 0, so that works just fine.

Hi,
for sun through glass with specular material you need to verify that the "Alpha shadow" option is always enabled in the kernel settings and the "Fake shadow" option is enabled too in the specular material settings. The glass geometry has to have thikness otherwise it react as a big lens. Another option is to use a glossy material instead with a falloff node in the opacity, with this material the geometry does not need the thickness and you can find a version of it in the LiveDB>Materials>Non-Organic>Glass>glass fake falloff.
ciao beppe

Thanks for the tip beppe.