Importing object from AutoCAD to Max, why not smooth?

[CADIDAC]

When I import an object from Autocad into 3dsmax, how do I get the object to appear smooth, and not striated?

[Cad64]

:huh: Can you post a screen shot? Not really sure what you mean? :unsure:

[CADIDAC]

Sure thing:
http://img525.imageshack.us/img525/7476/screenshotew0.jpg

[Cad64]

Hmmmm, that's quite an interesting model you have there. How did you create it in Autocad? Is it a solid or surfaces? It doesn't look like it imported cleanly into Max. If you want to post the dwg file, I can play around with it and see if I can get it into Max.

[CADIDAC]

Thank you so much.

It is just an extruded cylinder, unioned with a half circle that was lofted into a rectangle. That lofted object was mirrored a few times to create the rest. I planed on using the "twist" command in max to twist it 180 degrees. This is all in an effort to make a crude model of this:

http://www.bluenergy-ag.net/images/prod_turbine.jpg

[Cad64]

Yah, Max doesn't like that Cad model. You will have much better luck doing the whole thing in Max. I created the model below pretty quickly by just drawing the shape outline with a circle and a couple of splines. Then I booleaned everything together, extruded, applied a twist modifier and then a smooth modifier. It's probably not exactly what you're after, but I think it's pretty close and only took a few minutes.

[CADIDAC]

Wow that looks great. Thank you for taking this time to help me.
I have never drawn anything in Max before, I have only used it for bringing in cad models, applying materials, and rendering them at an acceptable level. After you draw the circles and splines, how do you tell Max that you want to create a region out of what you have drawn, so that it can be extruded? Is that effectively what booleaning everything did?

[Cad64]

The boolean just joins the circle and the splines into one complete outline. Once you have everything joined, the next step is to select the outline, right click and select "Convert to Editable Poly" from the pop up menu. This will convert the spline object into a region that can be extruded.

[CADIDAC]

Is there a trim command in Max? If not, maybe I should find another way to draw this:

http://img153.imageshack.us/img153/9554/maximagehn8.jpg

[Cad64]

No, there's no Trim in Max.

You could create the outline profile shape in Autocad and then import the 2D linework to Max. Then just select it and apply an Extrude modifier to it. Once the shape has been extruded, right click and "convert to editable poly". You will probably have to flip some of the polygon faces though. Especially around the inside of curved areas. They sometimes get inverted.

Well, I'm off to bed now so good luck. :wink:
I'll check back in the morning. :)

[CADIDAC]

Thanks again for your help Cad64. I followed your instructions, and the outcome is much better. However, I don't think I had to flip any polygon faces? Maybe that is why yours was smoother than mine?

http://img504.imageshack.us/img504/7356/editablepolyhz8.jpg

[Bikoholic]

Actually there is a trim command in 3DSMAX. It is located under the spline modifier menu. However CAD64 is correct it's easier and more accurate to just draw the spline in AutoCAD and import it into max.

[Cad64]

Actually there is a trim command in 3DSMAX. It is located under the spline modifier menu.

:o Oops, I stand corrected. Thanks Bikoholic. :thumbsup:

[Cad64]

Thanks again for your help Cad64. I followed your instructions, and the outcome is much better. However, I don't think I had to flip any polygon faces? Maybe that is why yours was smoother than mine?

No, if you had backward facing polys you would know it. They would either show up as black or they would be invisible. Your's look fine. You should turn on "Edge Faces" to see your tessellation lines. It looks like you don't have very many. Hit the "Tessellate" button under the "Edit Geometry" section, one time, to add more resolution to your model.