Gabi opened this issue on Feb 27, 2000 ยท 12 posts
Gabi posted Sun, 27 February 2000 at 5:36 AM
Hi all, I tried to create a "lens effect" in Carrara by placing a glass sphere on a wood table (plane) and placing a bulb or a spot light directed such that the shadow pointed to the camera. What you should see is a light amplification (meaning a bright light spot) in the "shadow" of the sphere. This didn't work, even when the render settings were adjusted to the best possible mode with a ray depth of 15. Can anyone help? To see what I am talking about have a look at the Bryce image at the following URL: http://www.gdiekert.de/3d_test/Bry_1_12.jpg Any help is appreciated! Happy rendering! Gabi
ClintH posted Sun, 27 February 2000 at 6:58 AM
Gabi - I see what ya mean. I havent tried that. I might have a chance to try and reproduce it here.. I'll see how the day goes. BTW - One time, you'll like this, I had a sphere in a basic scene, similar to yours, and I got a square shadow from the sphere...no lie. Very strange. I showed my wife she thought it was funny. I thought it was strange.. ;) Anyway - There seems to be some interesting issues with C that pop up from time to time. Clint
Clint Hawkins
MarketPlace Manager/Copyright Agent
All my life I've been over the top ... I don't know what I'm doing
... All I know is I don't wana stop!
(Zakk Wylde (2007))
Gabi posted Sun, 27 February 2000 at 9:43 AM
Thanx for the reply. I would be glad if you could try to set up this simple scene. I am just not sufficiently experienced with Carrara to decide if I did something wrong or if the renderer just doesn't render this scene correctly. Unfortunately, even more expensive programs seem to have trouble with that. I can predict that the result won't be perfect anyways, since the spectral colours of the visible light (the rainbow effect) cannot be displayed by ANY raytracer (as far as I know). However, the lens effect should be seen (it IS seen in Bryce). BTW: The best renderer I have seen so far to render this effect was that of Real 3D. This is nearly perfect! "C"U, Gabi P.S. Keep up the good work in this forum 8^)
ewinemiller posted Sun, 27 February 2000 at 11:22 AM
Carrara doesn't support caustics, so you won't see the light amplification you're looking for. Of course, you can fake it with some gels and strategically placed spot lights. Eric Winemiller Digital Carvers Guild Freeware and commercial 3D extensions http://digitalcarversguild.com
Eric Winemiller
Digital Carvers Guild
Carrara and LightWave
plug-ins
ClintH posted Sun, 27 February 2000 at 11:35 AM
OK - I rendered this at the highest setting for detail. I tried the Glass shaders and they didnt do it. I got a solid shadow. So - I tried a transparent shader. Well look at the shadow! Thats wrong. It shouldnt be solid. 
Clint
Clint Hawkins
MarketPlace Manager/Copyright Agent
All my life I've been over the top ... I don't know what I'm doing
... All I know is I don't wana stop!
(Zakk Wylde (2007))
ClintH posted Sun, 27 February 2000 at 11:40 AM
I justed posted this to the Carrara mailing server. I will see if this is a bug or if we are overlooking something. I'll post back when I get more information. Clint
Clint Hawkins
MarketPlace Manager/Copyright Agent
All my life I've been over the top ... I don't know what I'm doing
... All I know is I don't wana stop!
(Zakk Wylde (2007))
ewinemiller posted Sun, 27 February 2000 at 11:52 AM
Clint, Just turn on light through transparancy on the renderer. It will give you what you are looking for. Eric Winemiller Digital Carvers Guild Freeware and commercial 3D extensions http://digitalcarversguild.com
Eric Winemiller
Digital Carvers Guild
Carrara and LightWave
plug-ins
Gabi posted Sun, 27 February 2000 at 11:53 AM
Great, Clint and Eric! Thanks a lot for your help. I would really be happy if this would be updated - maybe in a later version (if there will be a later version :-( ). I am trying for nearly one year now to set up a scene I need this feature for. I hope I don't have to wait another year! Imagine (well, this is not my scene) that you want to create an outdoor scene where the sun is shining through a wine glass sitting on a table... Doesn't look very realistic when the wine glass just produces shadows. BTW: I am having the same problem in Cinema 4D; however, I just have the demo version (I thought about buying it, but only if it solves that problem) and couldn't get it to work until now (maybe there is a way to do it in this program though). Clint, if you set the renderer to transparency with through light (or similar - I don't remember the exact words; sorry, but I am German), you get slightly better results (the shadow is just not as dark ;-) Gabi
ewinemiller posted Sun, 27 February 2000 at 11:56 AM
Here is a test image 
Eric Winemiller Digital Carvers Guild Freeware and commercial 3D extensions http://digitalcarversguild.com
Eric Winemiller
Digital Carvers Guild
Carrara and LightWave
plug-ins
ClintH posted Sun, 27 February 2000 at 12:39 PM
Man, I have all that turned on. OK - Now that I see it rendered by someone else I must have something set wrong. Damn it. I'll poke around more. Thanks Eric! Clint
Clint Hawkins
MarketPlace Manager/Copyright Agent
All my life I've been over the top ... I don't know what I'm doing
... All I know is I don't wana stop!
(Zakk Wylde (2007))
ewinemiller posted Sun, 27 February 2000 at 1:03 PM
I played around with it a little more and was able to recreate the problem. Seems soft shadows don't work with transparent objects. Eric Winemiller Digital Carvers Guild Freeware and commercial 3D extensions http://digitalcarversguild.com
Eric Winemiller
Digital Carvers Guild
Carrara and LightWave
plug-ins
ClintH posted Sun, 27 February 2000 at 1:30 PM