Boolean Cutters

[wildcard]

I’ve played around with Boolean cutters several times now and I’m pretty pleased with how simple they can be used for cutting shapes.

 

However, I’ve been digging through the project files on the A:M Extra DVD and I’ve not (yet) found a project that makes use of a Boolean Cutter, instead, I only see very skilled spline modeling of which I can only dream of.

 

I did a quick search hoping to find a possible reason why I don’t see it used often and if there are any downsides to using Boolean Cutters.

[Rodney]

The primary reason many modelers might shy away from Booleans in A:M is because they plan to use their models in other programs or game engines.

As Booleans in A:M don't deform/reform/transform the actual mesh of a Model. exporting the model to other formats will leave the original mesh in it's unchanged state.

 

In many polygon programs Booleans aren't used in animation. They are used as Modeling tools exclusively.

That's where the benefit of Boolean cutters tends to end for mesh deformers.

 

The main benefit to Booleans in A:M is that they are implemented at render time, thus reducing the processing time necessary with denser meshes.

Booleans in A:M are therefore not simply Modeling tools but are optimized for animation, which is harder to do when dealing with deformers that actually change the geometry of a mesh. Yet another powerful aspect of Booleans in A:M is that they are (or can be) specified. That is to say, by assigning them to a heirarchy of Bones, the Booleans can cut (and color/texture) meshes depending on the relationships you specify. In this way they can cut through one part of an object yet ignore another entirely... while being animated.

 

We can exploit the power of Booleans best if/when we plan to keep a project inside A:M.

 

You are more likely to see Booleans in shared Project files rather than in individual Models on the Extra DVD because that collection had an expectation that anyone looking for the Models would primarily be interested in the model's geometry. As it isn't always obvious, Models with Booleans should have the word Boolean listed somewhere in the file to remind everyone using it the Boolean cutters are there.

[wildcard]

The primary reason many modelers might shy away from Booleans in A:M is because they plan to use their models in other programs or game engines.

As Booleans in A:M don't deform/reform/transform the actual mesh of a Model. exporting the model to other formats will leave the original mesh in it's unchanged state....

 

Thanks,

 

I hope that in the near future, my modeling skills have improved to such degree, I'm able to do with out the Boolean cutter. but for now it will do just fine.

 

A:M is just a hobby, I've no plans or goals set to have what I create to be used in other programs. Should those plans, I know I've to stay clear from Boolean cutters then.

[robcat2075]

I'll also note that booleans such as polygons modelers have that actually cut the mesh don't always work.

 

You can put two shapes together, tell one to cut the other, wait for it to chug through all the calculations and then get the message "Operation failed."

[Rodney]

It's been so long since I've tried any Boolean type cut in a poly program that I've thankfully forgotten the experience.

 

Truth in advertisement... I just remembered another important thing about Booleans in A:M.

Something else you should do to get the most out of Booleans in A:M is to close the mesh (any closed mesh will usually do).

If the mesh is left open A:M may not know whether to render the geometry from certain angles because it can't read your mind to know what to do.

It may interpret an opening where you don't intend one to be because of the angle of view.

So... avoid all that... tell A:M what to render by closing the mesh so the Booleans can cut cleanly and clearly through.

 

This doesn't mean that you cannot get away with cutting through open meshes in A:M but when you do just remember that you get what you get and not always what you want to.

[pixelplucker]

Here is use for a boolean cutter because it is a huge hassle to model this with splines and have it look good.

Not sure how the dimples would work with Newton though.

Dice.zip

[wildcard]

Here is use for a boolean cutter because it is a huge hassle to model this with splines and have it look good.

 

That`s pretty much the exact reason I'm not touching my now correctly shaped and beveled pentagon.

[John Bigboote]

Booleans are great. Make sure:

 

-Your normals are pointing right ways (out for the positive shape, in for the negative cutter.)

-Your 'cutting' geometry is closed.

-Your camera never passes thru the boolean.

 

The MAIN downside, in my book- is that you have to do a render to see their effect. So your model will look kinda weird until you render.

 

HERE is an old animation from my archives, booleans in motion:

AMbooleans.mov

[johnl3d]

Some of my attempts

 

http://www.hash.com/forums/index.php?act=a...ost&id=4204

 

http://www.hash.com/forums/index.php?showt...&hl=boolean

 

 

http://www.hash.com/forums/index.php?act=a...st&id=42026

 

http://www.hash.com/forums/index.php?showt...&hl=boolean

[wildcard]

Did a few test renders and the Boolean Cutters are working fine. The air ducts shape is nicely cut out of the pentagon (shaded side)

 

How ever, I'm encountering odd vertical lines and I don't know why.

Instead of creating yet another topic, I'll just ask the *Off Topic* question in here.

 

The top panels of my Mad Cat it's bird like feet have odd vertical lines running through it.

 

When I only render the panels alone, I don't have these odd vertical lines.

 

Anyone know a cause?

[Rodney]

From the looks of your recently posted animation I'd say you figured out what was causing those lines?

Not sure but if you did I'd love to know what it was.

 

You might want to remember what creates those lines. It's a pretty neat effect.

[Gerry]

I had a problem with lines like that awhile ago, and I believe it was caused by the type of shadows I was using, i.e., z-buffered vs. ray-traced. Don't remember which was causing the problem but switching made the problem go away. I'm pretty sure the shadow type is set in the light settings.

[robcat2075]

Z-buffered lights have a "bias" setting for dealing with "self-shadowing" artifacts. That may have been the problem.

[wildcard]

From the looks of your recently posted animation I'd say you figured out what was causing those lines?

Not sure but if you did I'd love to know what it was.

 

You might want to remember what creates those lines. It's a pretty neat effect.

 

I'm not fully sure if I truly fixed it and what is the exact cause of it. But I believe it had to do something with two patches, laying on top of one another or internal patches.

 

My model was made up out of stacked pieces. So I had patches stacked on top of patches even though there was a decent amount of spacing between them.

 

There is the beveled rectangle (fully closed), with to the sides and on top a cut in half beveled rectangle, the top panel, is a slightly tweaked rectangle to have a bit more curve to it and the very important rivets to complete it all

 

I could only see these vertical lines on the top panels, but not on the sides ones that where basically the same.

I've tried attaching the top panel, but at first it didn't look like it solved the problem, until I noticed I had still a patch forming underneath the the panel (a patching with in a model). After some tweaking I removed they internal patch and that solved my odd looking vertical lines problem.

 

I discovered the same vertical lines on the center beveled pentagon and I feared I had to go through modeling hell to get that fixed with out screwing up a well shaped beveled pentagon, but turned out to be quite easy.

 

 

When I get home, I'll upload up the version that had these vertical line problems, just to rule out it's a problem on my side. This talk about z-buffers and lights makes me want to see what happens if I rotate the model 90 degrees and see how the side panels react when they are facing upwards. If they also get these vertical lines distortion than it might very well be a light thing in combination with a underlying patch. But that`s just me guessing and trying to make sense of it all.

[pixelplucker]

Make a copy of the model for backup.. Break some of the splines that come to that patch "k" key and see if there is another patch in the same space. It does look like there are double patches.

 

If not then it might be some long edges causing it. I recently had a shape that looked similar. I fixed it by selecting the edges that made up the patch and flipped them over and re-attached it. I noticed there was a problem when I couldn't flip the normals on it.

 

If you show normals, select the patch and try flipping it and if it doesn't change then that maybe the case.

 

You could always post the model or part that is a problem and we can all pick, poke and prod at it.

[wildcard]

I didn't save any Choreography settings, what had me spooked for a second.

 

When I did a quick setup and a render, I could not see any vertical lines.

Played around with the light a bit (angles) before I could reproduce it again.

 

I also rotated my model 90 degree's on to it's side and the side panels now also showed the vertical lines.

 

This still has me worried a bit, that I may still have this glitch in my current project, but I've a different lighting angle. But will test that out later.

For now, you guys have fun toying around with it, if your looking to reproduce this vertical line distortion, where I wasn't really happy with

 

temp.prj