Hi there!
today i ran into a problem when trying to recreate the image3d shaders in jason iversen's intro to shader writing. i hope it hasn't been asked already (at least i didn't find it).

before i did this intro, i tested some shaders from the shader pdf and all worked fine but when i tried to do the image3d shaders, i didn't know where to put the .ds files.
i put the .vex file into vex/image3d (as this directory was already there and the other i3d shaders inside) and moved the .ds file to vex/dialogs/image3d. finally i put a file called VEXimage3d into the vex directory and put the link to the .ds inside (like in the example for the first sop).

does anyone one what i did wrong (everything ?) and how to correct it?
many thanks in advance

You're going about this in the “old” and difficult way.
Check the vid tutes on OTL's. And search this forum for more great advice on importing shaders.

To solve your problem:
You simply need to compile the vex code into an op type library file.

All you need to do is use the following command.

vcc -l ShaderName.otl ShaderName.vex

This will create an .otl file which can then be imported through
File>Import new op type

It will put everything in the proper place for you.

Easy as pie

thanks a lot for the advice!

just tried it out and it worked

but i have another quick question ops:
when using the VEX builder, how can i add “inputs” to the output VOP? for example the output vop for i3d shaders only has one “input” (density), but in houdini's shader help file it says, that you can add additional channels to an image3d file with “export variables” (searched for that one in the forum, but most of you seem to prefer code ).
how can i introduce such an export variable to my vop shaders?
i tried “export parameter” in the parameter vop, but that seems not to work.

thanks a lot

It works.
Use input value - ON
Export parameter - ON

You can check i3d file with i3dinfo.exe

Thanks a lot guys :mrgreen: