AutoCAD Modeling - Rendering in VIZ

[Eric]

To all those who model elements in AutoCAD, and render in VIZ:

 

When you model an object, do you use strictly faces? Or do you start with a Solid object, and explode it down to faces, and delete the surfaces that won't be visible?

 

I've always modeled strictly with Solids, and kepts the model completely intact, without exploding and deleting faces. However, I'm starting to realize this might be a rookie mistake, which is making my rendering/radiosity calculations longer than they need to be.

 

Any quick tips on a method of modeling in AutoCAD for linking into VIZ?

 

Eric

[Vince Paske]

I model in AutoCad using solids and keep the geometry intact when I bring it into Viz using the file link manager. Normals tend to flip when bringing in faces from AutoCad and I don't think there's any advantages to deleting unseen faces, but it might lighten the model and reduce load by a few seconds - which you should weigh against the time spent exploding and hunting down all the faces. Stick to solids dude and you'll have an easier time editing the model as it changes too.

[STRAT]

if you know solids then stick with solids.

if you know surfaces then stick with surfaces.

 

Viz/max deals with both very well but has different issues with each method too.

 

i always use surfaces over solids as it's infitesintly more accurate than modelling in solids, altho solids is a faster to edit.

[CHE]

I used to have the same darn question. Solids or Surfaces? Here is my input:

Solids: Fast Modeling, Heavy Models, Hidden faces, less flexible.

Surfaces: Slow Modeling, More control over the model, vertex to vertex modeling (more accurate), very flexible.

Conclusion: Go ahead and learn how to model in MAX/VIZ. I did and I have no plans to go back to CAD. You won't believe how fast, accurate and flexible Max/Viz is. In one word, I have control over every single step of my modeling. Back and forth. Forget about importing exporting and the so called file link feature. You don't need to go through all this. My two cents.

[Eric]

I assume when you refer to faces as being more accurate, you're saying in terms of lighting calculation. Otherwise, I personally think modeling with solids is much more accurate for me in terms of feet and inches. Also, since my 8-5 job revolves around drafting services, I'm much quicker with Autocad 2000 than I would ever be modeling with faces inside of VIZ. I think VIZ leaves much to be desired for its modeling capabilities. Over the last few days, I've been working on modeling with faces to see if it makes a noticeable increase in my radiosity calculations.

[CHE]

I think that is very important to match vertices. With solids you will end up with isolated vertices and useless extra faces. Have you tried MAX 5? In MAX I start by creating a very quick/ruff model using standard primitives and then I modify the geometry as I go into detail. I do this by using MAX's modifiers (which are priceless), deleting, and creating new faces, etc...Don't get me wrong, there is not a right or wrong way to model. If you are used to working with solids and it gives you a good result then just focus on that. Regards.

[Dave Buchhofer]

Solids CAN be useful, but once you get used to editable poly's in max/viz there really is no going back, its somewhat different goemetric ideas, but they both work about the same, though coming from opposite ends of the spectrum.

 

truthfully, model however you are fastest when you need it, and model to learn other styles when you have that time allowance, it WILL come in handy, the fastest way to do something is usually a combination of 3 or 4 different styles.

 

Basically, do what you're comfortable with.

 

If your target is radiosity however in the long run, i would say to start working on Viz modeling. Using meshtools (Or the tools now in Max5) its very very intuitive. you just need to think in terms of edges and intersections instead of unions and subtractions.

 

Its all dependant on the model/design