Hi,

I had a few questions about the file format for image 3D files.

1) Is it true that only the “density” channel is written to the file? I'm writing some i3D VEX code based off of the tutorials that Jason Iverson wrote on odforce (thx again Jason!) but am confused a bit. It would be so handy to be able to write additional data into the i3D file! I gotta feeling this is being done, but not sure how yet. In one example (see below), Jason declares a var to be “exported”, but when I gen up the i3D file, it appears only the “density” channel is written.

2) Is the i3D file format published anywhere? I can dump the contents using a utility like “od -vcx” but it would be a lot easier if I didn't have to reverse engineer it …

3) Where does one place the .ds file. I was able to make an OTL and import that into Houdini, but I don't feel 100% comfortable with OTLs yet and would like to know how to “install” the i3D VEX function. I looked through the $HFS/houdini/vex tree and didn't see any examples I could learn from.


This file format is really interesting and if I can get more data into the file, I've got ideas for using Real Flow data with 3d “texture” files … groooooovy! If it can't be done I suppose I could write a plugin to create my own file format, but would rather not create yet another protocol to deal with …

Thanks!


–Mark




image3d blend_attribute( vector freq={1,1,1} )
{
float d = 0, max = 0;
vector clr = 0;
export vector blended_color=0;
forpoints( P )
{
d = mdensity(P); //get density of metaball
if (d > max)
{
clr = mattrib(“Cd”, P); //get the unblended color attribute
max = d;
}
blended_color = d * mattrib(“Cd”, P); // blend based on density
}
density = max;
}

Allright!!! Did a search through previous posts (I know I should have done that first …) and found the error I made to export more channels into an i3D file! I needed to export one of the parms to the VEX function.

Oh man, this is getting interesting! :-)


–Mark


image3d blend_attribute( export vector blended_color=0; vector freq={1,1,1} )
{
float d = 0, max = 0;
vector clr = 0;
forpoints( P )

…

}

Yes, you can output multiple channels of data to i3d as you've already discovered. As for the file format, it's proprietary. Having said that, you can use i3dconvert to convert .i3d to .geo. (see "i3dconvert -")

Perhaps Frank Firsching could provide further insight for hacking i3d as he's already done it.

edward
Having said that, you can use i3dconvert to convert .i3d to .geo. (see "i3dconvert -")

Perhaps Frank Firsching could provide further insight for hacking i3d as he's already done it.

i3dconvert looks interesting but I'd like to be able to “bake out” i3D files from the Real Flow import SOP, instead of having to run a VEX function.

So … if Frank would be so kind as to share his insights, it'd be very helpful! :-)


–Mark

call me necrophile for digging out this old thread

did someone manage to convert volumes in bgeo into i3d's with the i3dconvert command ?

thanks!!!

Seb

xionmark
2) Is the i3D file format published anywhere? I can dump the contents using a utility like “od -vcx” but it would be a lot easier if I didn't have to reverse engineer it …

Just to echo this question.
Are there any published documentations on i3d's format/spec?