Loading...
> >

[solved] lantern iray glass shader mystery

bitwelderbitwelder Posts: 212
edited October 2015 in Technical Help (nuts n bolts)

I'm making a lantern which uses a mesh/emitter for a flame and it has glass panes on 4 sides. When the lantern is placed at 0,0,0, it emits light as expected, evenly in all directions.  But if I just move the lantern along the ground in any direction, it stops emitting evenly.

 

Some things I've tried with no significant difference--although the quality of light may change slightly, the un-even emission pattern remains:

-- applied all the different glass and water shaders available under the iray presets

-- modeled the glass panes with thickness (6 polygons per pane), used single pane (1 polygon) glass, used double pane glass (2 polygons); also tried variations with normals flipped in different directions

-- turned "thin walled" option on and off in glass material surface settings

-- rotated the light/glass in the Y 90 degrees--- no difference, the pattern appears exactly the same--the pattern does not rotate with the light

-- removed the glass, and the problem was gone; it went back to even emission in all directions

 

For simplicity's sake I recreated the problem by making a primitive cube and applying the Iray "Glass - Solid- Clear" shader, then a sphere to which I applied Iray "emissive" material. I needed to tick "Two-sided light" to make the emitter work. Parented the sphere to the cube, and created a primitive plane for a ground. See results in attached jpeg. I'm using Daz Studio 4.8.0.59.

 

Any ideas what might be going on here? Why would just moving the lantern change the emission pattern? What are some more things I can try? Thanks!

 

 

image

emitterIssue01.jpg
992 x 1026 - 180K
Post edited by bitwelder on

Comments

  • FishtalesFishtales Posts: 6,119

    The shader for glass in a lantern is Glass- Thin - Clear. The Glass - Solid -Clear one is treated as a solid object and not a slim pane of glass so the whole of the inside of the lantern is treated as solid glass by the Iray renderer.

  • bitwelderbitwelder Posts: 212

    Thanks for the response. I tried applying Glass - Thin - Clear to the cube, but I'm still getting the irregular emission pattern...

     

     

    emitterIssue02.jpg
    460 x 421 - 41K
  • SzarkSzark Posts: 10,634

    Did you turn ON Caustics in the Render settings Pane as I found that to be the key when lighting through glass.

  • bitwelderbitwelder Posts: 212

    With Caustics turned on it is working great. Thanks very much, Pete!

  • SzarkSzark Posts: 10,634

    Sweet and my pleasure to help.

Sign In or Register to comment.