Hiding Objects Inside Another Object During Render

[user_deleted]

Is there any way that you can create an object or mesh and when you render, have everything that's inside of it to be invisible? For instance, have blobby particles flowing through a transparent tube, and using sort of an inverse tube object or mesh outside of the tube to hide the parts of the blobbys that are poking through the surface of the tube.

[joojaa]

Actually yes its possible to raytrace this, but theres no way to act on the mesh data because implicit surfaces dont get meshed untill theya re sampled.

[user_deleted]

Sorry, I'm not sure what that means. Is it possible to get the effect I am looking for? I just need the blobbys to not show up outside of the tube, and go right to the edge inside. Is there any way to accomplish this? Or do I have to try something else like an animated shader or something? I don't have unlimited, so I can't use fluids, which would probably make this effect easier.

[joojaa]

QUOTE(Brian Langeman @ 02/02/07, 05:43 PM) [snapback]258746[/snapback]
Sorry, I'm not sure what that means. Is it possible to get the effect I am looking for? I just need the blobbys to not show up outside of the tube, and go right to the edge inside. Is there any way to accomplish this?

Yes, I said it can be accomplished by raytracing. But youd have to search for the shader or make it your self. Its called ray traced boolean. Its a sort of winding order shading trick. But it does not ship with your vanilla maya. (less than half of anything worthwhile does, but they dont ship with max, xsi, houdini, mentalray, vray, or brazil either. Because by definition ist not worthwhile if everybody has it)

anyway one can be found here http://www.binaryiris.com/main/?id=BoolTrace. google for maya version i think Sandstr

[user_deleted]

Thanks Joojaa. I found the one that Sandstrom made, but I'm having some troubles getting it to do anything. I've installed all the files just like the text document said, and I've updated the rayrc file too. It shows up in the Shader Manager, and I can also create the node and assign it to my test scene of a sphere and a cube. I set up my render globals to Mental Ray and Production Quality. Then I link a Blinn material to the shader input on the BoolTrace nodes, and assign a different one to each object. Then I fill in the renderIn and volumeName fields and try and render it.

In the script editor it gives me this error "// Warning: (Mayatomr.Custom) : C:/Program Files/Autodesk/Maya8.5/mentalray/include/BoolTrace.mi: couldn't find shader library //".

In the output window it says this "PHEN 0.3 error 051011: shader "BoolTrace" not found".

I have no idea where to go from here cause it seems to be looking right at the BoolTrace.mi file and not finding the shader in it or something.

[joojaa]

Its complaining that it cant find the dll, it too must be copied to your search paths. However youmay need to recompile the plug at ome point. (ps if you have maya 8.5 you dont need to edit the rayrc juts copy the dll, mi and mel files in place and restart maya)

But id ont actually like the way the plugin is made, its way too restrictive.

[user_deleted]

I copied the dll file into the mental ray/lib folder and I recopied everything hehe. Then I deleted the lines from the rayrc file. Still nothing, although when I delete the lines from the rayrc file, the output window says that the BoolTrace function is undefined. What is recompiling the plugin, and do I need certain software for that?

I wish there was another way to do this, but nothing else I try looks like what I want. Will this even work with blobby surfaces? You said something about implicit surfaces before, and I'm not sure what that is.

Also, is it possible to do this in Maya Fluids? Or do you get the same problems with liquid penetrating through geometry. It obviously wouldn't be a problem if it was on a surface or something where you don't need to see the other side, but unfortunately I do need to see the outside.

[joojaa]

Sure its a ray trace trick. Read the manual it expleoins how t install custom mentalray shaders very well.

Its impossible for me to debug your operating sytem form over here. (theres just way too mucj you can break in it that can cause anything). Thats the main reason any sane 3d production needs a computer genius, as its not just the 3d app you need to worry about but just about every resource the computer has is maxed out in any sane 3d production environment

QUOTE
Also, is it possible to do this in Maya Fluids? Or do you get the same problems with liquid penetrating through geometry. It obviously wouldn't be a problem if it was on a surface or something where you don't need to see the other side, but unfortunately I do need to see the outside

haven't tested, if you man ocan then sure but i doubt a volumetric fluid will work, note i don't use boolTrace but i use something very similliar except its selection logic is a bit more expandend.

as for implicit

http://en.wikipedia.org/wiki/Implicit\_surface