question about the renderers (for experts)

[rirad]

I think the space in between is considered empty. Unless you use a 3D (fog) shader (don´t know why you should), than it is considered ´full´ I guess.

Don´t know how it works in in other render engines but I guess it´s the same.

[ThirdEye]

Why? For transparent objects to fill the empty space with glass ;)

[Srek]

Hi,
any render engine does this that is able to calculate refractions.
From what i know every render engine does only calculate the needed part. They will treat non transparent parts as simple opaque surfaces since there is no need for additional calculations.
Only one part is sometimes interesting and that is the existence of a backface, but that has nothing to do with volumetric information.

Regards
Srek

PS
what should a renderer do with informations about the inside of opaque objects?

[Per-Anders]

what you're refering to is volumetric rendering thirdeye. cinema does volumetrics much like most packages in that when it encounters a volumetric surface is then takes samples inbetween the back facing surfaces of an object at measured distances (just like with volumetric lights). however c4d has no inbuilt volumetric shading system apart from pyrocluster which uses the voxel method (area close to a point is sampled). it does have the bhodinut shaders, but again those mostly take surface values rather than actual volumetric information. currently on c4d the only trully volumetric surface to surface material is the fog, one day however c4d will have useable and controllable volumetrics. but for the meanwhile surface shading is perfectly adequate, and you can create ultra real glass if you want with that... volumetrics always take forever to render.

[Mike Abbott]

There are some shaders that will use this 'closed volume' info - but non for Cinema as far as I know.

Take the glass example. Glass has a colour - normally green. Imagine you looked through a rectangular glass block that was much longer than it was wide. Look through it long ways and the colour is more intense. You are looking through more volume - all of which is green.

Here's a shader for EI that uses this volume info. I wish we had one for Cinema (ps: I have asked Konkeptoine - no go I'm afraid).

http://www.Konkeptoine.com/
Look up the RTS glass samples.

Mike Abbott
www.vgd.co.uk

[ThirdEye]

@mdme_sadie: for example look at this image, it was SI|XSI made, look in particular at the bottom of the coke bottle, it seems really full of glass, i think he used a volumetric shader, don't you? I'm not able to get a similar result in C4D.

[Per-Anders]

buy bhodinut Praline, it has a depth shader, or you can use distance falloff which is free.

both of these will do what you want (i.e. deeper = more colour)

praline has a lot more control though. i'll try to post some pics.

oh and i'm uncertain if that's a volumetric shader, it would take forever to render, and it's much faster to do normally, the bottom of that bottle is merely a reflection.... try using two channels one for front and one for back with different refractive indexes and reflection types (i.e. for the back you want a sharp falloff to match the refractive coefficiant).

[ThirdEye]

Originally posted by mdme_sadie
buy bhodinut Praline, it has a depth shader, or you can use distance falloff which is free.

both of these will do what you want (i.e. deeper = more colour)

praline has a lot more control though. i'll try to post some pics.

oh and i'm uncertain if that's a volumetric shader, it would take forever to render, and it's much faster to do normally, the bottom of that bottle is merely a reflection.... try using two channels one for front and one for back with different refractive indexes and reflection types (i.e. for the back you want a sharp falloff to match the refractive coefficiant).

1) I know XSI has a volume glass shader, are you sure that the bottom of the bottle has a simple reflection?

2) What do you mean for a "sharp falloff to match the refractive coefficiant"?

[rirad]

@ThirdEye: Not an answer to your question but this might interest you:
http://forum.bhodinut.com/viewtopic.php?t=631

[ThirdEye]

Originally posted by rirad
@ThirdEye: Not an answer to your question but this might interest you:
http://forum.bhodinut.com/viewtopic.php?t=631

Thank you, I know it ;)

I think what I needed was a C4D plugin like Ogo Hikari's LW one :shrug:

[LucentDreams]

uhhhm firs tof all they are right there are glass shaders people have made for XSI with volume nodes in them to help caculate for certain effects, one example owuld be the XSI glass examples used by bjotto to make that cow render. I know from the guys site that hes was using the volume node to help create this effect, whether that bottle uses it or not I can't say.

MDME Sadie is right Praline has a this ability. But all I will say is be patient, beeeee patient. ;)

[ThirdEye]

mmm I'm patient... Now :p

[sanciok]

Maybe it's not what u're looking for. The Banji 3D shader provides to calculate your glass object as a solid, and u can also set the volume in this shader. Maybe is different than having a voume glass shader, but i think u can get some nice results with this.

[sanciok]

and u can also get some nice results using the fog channel.
In this shader i also used ChanLum in the luminance.
The fog channel is set at 177m.

[sanciok]

ouch... i just realized that i did something extremely similar to this thread.... Sorry...
http://www.cgtalk.com/showthread.php?threadid=23487

[CGTalk Moderation]

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.