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View Full Version : Cutting Through 3D Solids Using LW9



JanC
03-23-2007, 11:59 PM
I'm exploring ways to use a clip map or transparency map to cut through a *solid* object. (Please note that this is not a modelling question but a rendering question - I know how to model inner surfaces using boolean ops. I want to do this for reasons of rendering efficiency.) If the object is meant to be a solid then projecting a clip or transparency map through it should reveal a new inner surface through the object. What actually happens with the simple techniques I've tried - using transparency mapping on the surface texturing, or applying a clip map to the object in Layout - is that LW cuts away the polygons that form the outer surface of the object but leaves an empty space visible inside. Is there a way to achieve what I want, which is the appearance of a solid surface through the object?

Grateful for any suggestions.
Thanks.

Surrealist.
03-24-2007, 02:23 AM
Well, the thing is, I think you have to solve the faces issue. As far as I know it is either polygons or hypervoxels.

You can take an image and cut a hole though a subpatched object using displacement on one polygon, but to do it Lightwave generates thousands of polygons in the render. This still takes RAM and processing.

From the experiments I have done, a poly is a poly as far as render time and RAM - tested on poliginal objects, Subd objects and displacement objects. The render times and RAM are identical for each.

This left me to believe that it does not matter. Model as you would. It is the same problem all around and actually Subpatch objects in my opinion give you the most versatility and quality at render time.

As as far as hypervoxels are concerned, I'm not really familiar with what all they can do. Something to look into but the more complex you get with those the more render time.

But as far as geometry is concerned I am pretty sure you have to have a face of some kind.

zardoz
03-24-2007, 02:47 AM
I think that this tutorial will help you
http://www.newtek.com/products/lightwave/tutorials/animation/clip-map/index.html

Surrealist.
03-24-2007, 11:30 AM
That is a very clever idea and a great tutorial. Thanks for posting that. If the end goal is just to have the apparency of a solid flat face or image mask area that you can later add post processing to - then solved.

I may have completely misinterpreted the intent.

stevecullum
03-25-2007, 06:10 PM
I had the same issue a couple of years ago and used this plugin to solve it.

http://dodgy.ghostoutpost.com/Files/BooleanTexture.zip

I think you need to apply this texture as a clip map on both the cutter and object being effected. It might be what your looking for.