BMRT & Volume rendering

BMRT & Volume rendering

Post by Chris Thei » Sat, 08 Mar 2003 03:48:13



Hi there,

I'm a newbie using BMRT thus I'd need your assistance pointing me the way
with my following problem. In principle I do have 3D voxel data (the indices
respectively coordinates of cells plus a scalar value for each cell) for
radiation fields. This data should be visualized with volume rendering using
BMRT. Furthermore I'd like to add a 3D geometry which I can convert from 3DS
to a RIB file. Does anybody have a clue how create a RIB file for
visualizing my radiation data.

Sorry for any possible annoyance but I'd be really grateful if you could
tell me how to do it or possibly give me a hint or an example RIB file.

Thanks in advance
Chris

 
 
 

BMRT & Volume rendering

Post by Brian Perr » Sat, 08 Mar 2003 12:36:02


Chris,

Depending on the format of your data you could import it into any number
of modeling packages and save it as a RIB directly. You could also
create some type of script that would build a RIB file based on the data
you have collected using visual basic (or similar depending on your OS).
(Like adding a sphere to each coordinate you have stored and scaling it
by the X value.)

There's multiple ways to do it but I use a tool called Rhino3d which
comes with a free demo. You could import the 3ds file and save it as a
RIB and render it that way. There's also a Rhino plug-in I distribute
for free called RhinoMan which is setup to make rendering in BMRT (and
other renderers) much easier.

http://www.rhino3d.com
http://www.rhinoman.com

Brian Perry


> Hi there,

> I'm a newbie using BMRT thus I'd need your assistance pointing me the way
> with my following problem. In principle I do have 3D voxel data (the indices
> respectively coordinates of cells plus a scalar value for each cell) for
> radiation fields. This data should be visualized with volume rendering using
> BMRT. Furthermore I'd like to add a 3D geometry which I can convert from 3DS
> to a RIB file. Does anybody have a clue how create a RIB file for
> visualizing my radiation data.

> Sorry for any possible annoyance but I'd be really grateful if you could
> tell me how to do it or possibly give me a hint or an example RIB file.

> Thanks in advance
> Chris


 
 
 

BMRT & Volume rendering

Post by Chris Thei » Sat, 08 Mar 2003 17:02:45



Quote:> Chris,

> Depending on the format of your data you could import it into any number
> of modeling packages and save it as a RIB directly. You could also
> create some type of script that would build a RIB file based on the data
> you have collected using visual basic (or similar depending on your OS).
> (Like adding a sphere to each coordinate you have stored and scaling it
> by the X value.)

> There's multiple ways to do it but I use a tool called Rhino3d which
> comes with a free demo. You could import the 3ds file and save it as a
> RIB and render it that way. There's also a Rhino plug-in I distribute
> for free called RhinoMan which is setup to make rendering in BMRT (and
> other renderers) much easier.

> http://www.rhino3d.com
> http://www.rhinoman.com

> Brian Perry

Hello Brian,

thank you for your information. I'll checkout Rhino & your plugin.
Furthermore I'll implement an export filter in my software that will create
the spheres. Just one other question regarding the volume rendering. Any
idea which shader I could use or whether I could find one that might be
suitable?

Thanks
Chris

 
 
 

BMRT & Volume rendering

Post by Brian Perr » Sun, 09 Mar 2003 02:23:07


I'd take a look at fog, smoke, and supertexmap that come with BMRT and
attempt to write your own if that's feasible. BMRT isn't capable of
using "interior" volume calcs, only exterior, but you might be able to
fake it with some sort surface/volume shader depending on the effect
your looking for. Unless I'm cluless of what you after.

Brian




>>Chris,

>>Depending on the format of your data you could import it into any number
>>of modeling packages and save it as a RIB directly. You could also
>>create some type of script that would build a RIB file based on the data
>>you have collected using visual basic (or similar depending on your OS).
>>(Like adding a sphere to each coordinate you have stored and scaling it
>>by the X value.)

>>There's multiple ways to do it but I use a tool called Rhino3d which
>>comes with a free demo. You could import the 3ds file and save it as a
>>RIB and render it that way. There's also a Rhino plug-in I distribute
>>for free called RhinoMan which is setup to make rendering in BMRT (and
>>other renderers) much easier.

>>http://www.rhino3d.com
>>http://www.rhinoman.com

>>Brian Perry

> Hello Brian,

> thank you for your information. I'll checkout Rhino & your plugin.
> Furthermore I'll implement an export filter in my software that will create
> the spheres. Just one other question regarding the volume rendering. Any
> idea which shader I could use or whether I could find one that might be
> suitable?

> Thanks
> Chris

 
 
 

BMRT & Volume rendering

Post by Chris Thei » Sun, 09 Mar 2003 20:09:43



Quote:> I'd take a look at fog, smoke, and supertexmap that come with BMRT and
> attempt to write your own if that's feasible. BMRT isn't capable of
> using "interior" volume calcs, only exterior, but you might be able to
> fake it with some sort surface/volume shader depending on the effect
> your looking for. Unless I'm cluless of what you after.

> Brian

Thanks Brian for putting up with my stupid questions :-) The effect I'm
looking for is some sort of transparent cloud or fog with different colors
where each color represents a certain radiation level. I'll take a look at
those fog/smoke shaders that come with BMRT.

Thank you very much
Chris

P.S.> Is there a version of your plugin that works with Rhino 3.x 'cause
version 2.0 can't be downloaded anymore (at least I don't find it).

 
 
 

BMRT & Volume rendering

Post by Moritz Moelle » Sun, 09 Mar 2003 22:18:48


Chris,

Quote:> In principle I do have 3D voxel data (the indices
> respectively coordinates of cells plus a scalar value for each cell) for
> radiation fields. This data should be visualized with volume rendering using
> BMRT.

look at the ray marching shaders ('clouds' & 'hypertexture') included
with the material for the book 'Advanced RenderMan - Creating CGI For
Motion Pictures' (ARMan for short). The material is available online
here: http://www.mkp.com/renderman.
I also suggest using another RMan compliant renderer though, for pure
speed reasons -- Aqsis & Pixie are both open source, 3Delight is free.
Aqsis:    http://www.aqsis.com/
Pixie:    http://www.cs.berkeley.edu/~okan/Pixie/pixie.shtml
3Delight: http://www.3dlight.com/

Both shaders btw. do *not* require the renderer to support ray-tracing.

Cheers,

.mm