[tobyaxis]

Sketchup is a polygon modeler. Alibre is a NURBS modeler. The last time I looked, Alibre used the ACIS modeling kernel. Did they change something?

Alibre uses Direct X not NURBS.

[HuFlungDung]

Uh, NURBS is not a display method. I think you're confusing directx with opengl graphics rules.

Just for the heck of it, I modelled a 1" radius sphere. In NURBS, the filesize is 29kb. The model is accurate to .0001" The same object translated into an STL mesh of the same precision is 6.5 megabytes!

[BurrMan]

Hi toby,
Yes, this is a confusion with the "display mesher" that is used to present the viewport. The 2 industry standards are DirectX and Open GL. These are the systems that drive your Video card but have nothing to do with your modeling kernel.

Alibre uses the ACIS Modeling Kernel, and actually wrote a proprietary version of the STEP format to carry their parametric information. A normal STEP (NURBS) solid doesnt have the definitions in it to carry this extra information.

"NURBS" is the underlying definition of the geometry.

Actually, EVERYTHING you see on your "Computer Screen" is a ploygon mesh. This is done by your video card. You can see this happen by drawing a precisely defined NURBS curve and then start to zoom in on it. At some point, you will see the edges start to flatten out to lines, though the underlying geometry is still an actual perfect curve. A polygon modeler or any polygon format, is actually this faceted geometry. It is no longer a perfect definition, but a representation.

FYI

[BurrMan]

I may have caused the confusion with some stuff in previous posts with regard to "Meshing". There are 2 types of Meshing I refered to with regard to our discussion. The first is the "Display Mesher" which is basically the programs "viewport" and the code Alibre uses to display objects in this viewport. This is actually a very integral part of your application and has a very strong affect on how the program interacts with the viewport. It is one of the more complicated things the application has to accomplish and can make or break the app. (Usually either proprietarily written, or, as in many apps, like some of solidworks, licensed code from a company like TechSoft3d... "HOOPS3d")

The second, was refering to "Meshing your NURBS" to a ploygon format. This is the process that is done to "Dice up" your NURBS model into little triangles (Polygons) that will be representing the NURBS Data. The more simple meshers give an "Automatic result" with no control oner how things are diced up. Push button and what you get is what you get. Better Meshers will give you control over how and what gets diced and to what detail. This will be represented in the final file as Large "rough" triangles or many more smaller ones depending on the "resolution" specified. You will see this refered to in Polygon world as "Poly count". A single sphere can be a 1 meg file, or a 50 meg file for the same exact sphere. (18,000 polygones or 480,000)

They are 2 independant things and the diplay has no affect on the actual geometry. You can make a NURBS shpere look like a "hexagon" on your screen by lowering the display mesher settings in the app, but the NURBS sphere is still a perfect sphere. Once meshed to a Polygon format, if the resolution of the polygon mesher produced a hexagon, you now have a hexagon. (or in the case of 3d, some sort of polyhedron)

Anyway, FYI.

[ben_jackson]

BTW, I just found out that while there is a "$97" version of Alibre, that price point is only available with maintenance, so in fact the lowest price version of Alibre Design Standard is $197. I wish they'd been more honest about that. Makes me reluctant to buy it even if it is still a good value.

[BurrMan]

BTW, I just found out that while there is a "$97" version of Alibre, that price point is only available with maintenance, so in fact the lowest price version of Alibre Design Standard is $197.

197.00 is still an extremely good price for a Parametric modeler with the features that Alibre has.

[ben_jackson]

197.00 is still an extremely good price for a Parametric modeler with the features that Alibre has.

I agree. I just don't like hearing "$99" over and over and finally going to the shop to buy and finding no $99 and no explanation. It's worth $200, but the bait-and-switch will leave a bad taste in my mouth.

[tobyaxis]

197.00 is still an extremely good price for a Parametric modeler with the features that Alibre has.

This is true BurrMan but don't forget that there are specific functions and tools that aren't available in the standard version.

[BurrMan]

I agree. I just don't like hearing "$99" over and over and finally going to the shop to buy and finding no $99 and no explanation. It's worth $200, but the bait-and-switch will leave a bad taste in my mouth.

I agree. It is kindof prevalent now day's.....But I dislike it also.

don't forget that there are specific functions and tools that aren't available in the standard version.

Didnt think about that. I should re-evaluate the features available in this new package.

[ben_jackson]

Didnt think about that. I should re-evaluate the features available in this new package.

You really can't. The big items (like static FEA and a parts library) aren't in the "pro demo" even though they're part of "pro". My conclusion was that the quality of Alibre was uneven enough (good some places, bad others) that I wasn't going to risk buying the upgrades with no trial.

[tobyaxis]

You really can't. The big items (like static FEA and a parts library) aren't in the "pro demo" even though they're part of "pro". My conclusion was that the quality of Alibre was uneven enough (good some places, bad others) that I wasn't going to risk buying the upgrades with no trial.

I have Professional which includes the Parts Library, Photo Render, PDF BOM's, Prints & Solid Models, and Algor Design Checker. Professional comes with a lot which is why I have not upgraded to Expert.

In a few months I may need Expert for it's Motion API. With the Maintenance up soon it is going to cost a little more, but a real bang for the buck so to speak.

[scudzuki]

Regardless of what's missing from Standard vs. Pro and Expert, it's a hell of a deal for $200. I'm sorry I suggested it was only $97 and it sucks that they mislead you but I challenge you to find a competing package that does as much for anywhere near the price.

Joe