Curve smoothing when importing from AutoCAD to MAX

[Connect34]

Hello I'm new here. When I import a 3D model from AutoCAD to 3dsMAX I can slightly adjust the smoothness of the curves to keep the original design curve, utlizing the import options; however it still looks a bit edgy. What are some better techniques to maintain the original curve smoothness of objects when importing from AutoCAD to MAX? 

[darawork · Accepted solution]

3dsmax menu -> Import -> Link AutoCad (click browse to find your .dwg)

Attach the file, then go to the next tab and make sure 'Show reload options' is checked.

Then press reload.

In the 'File Link Settings: DWG options' window;

Set curve steps to 100 and maximum surface deviation for 3D solids to 0.1mm

I usually uncheck all the other stuff on all tabs, and leave defaults for Spline rendering.

Just a note: Make sure there are no 'Ray' lines in your AutoCad dwg. 3DSMax doesn't seem to like the concept of infinite lenght lines and will freeze up.

[Connect34]

This is similar to the settings I've tried. I hope this is more efficient.

[Connect34]

Thanx. I'm not seeing a tab that has "Show reload options". Is it in import settings? Also, can you further explain ray lines? I'm not exactly sure what ray lines are.

Also, is it possible to fully manipulate a curve when importing from AutoCAD to 3dsMAX?

[darawork]

On the 'Files' tab, at the bottom left there is a checkbox 'Show reload options'.

Ray lines: 'Ray' command in AutoCad draws an infinte lenght construction line, try it.

To manipulate AutoCad entities in 3DSMax the .dwg needs to be binded, or right-click and 'convert to editable mesh'. If the file is still in a 'linked' state it can not be manipulated, only moved in location.

[PROH · Accepted solution]

Hi.
1 - Darawork is talking about the DWG-Link, and you are talking about DWG Import. In DWG Import there are no "Show Reload Options".
2 - Once imported, you can "refine" the resolution of arcs and curves (Editable Spline) in the Modifier panel (Interpolation Roll Out).

Hope it helps.

[Connect34]

That's good to know. Thanx. I'll see what I can do with that.

[wladdes]

Hi guys.

here is the soución, you can give the resolution you want to mesh inserted, same for the shapes.

Greetings. I hope this thing to me has served.

[knmdk]

Hey PROH could you provide a bit more details on 2? How exactly would I smoothen my "Editable Mesh" after importing? I can't find any Interpolation Modifier roll-out. The import settings (Curve steps 100 and Max surface deviation of 3D solids 0.01) are not enough to get as smooth model as I'd like. 

[PROH]

Hi knmdk

As I wrote, you can refine the resolution of arcs and curves (editable splines) after import. I didn't write anything about mesh. Besides that, the "curve steps" is for arcs and curves, and the "surface deviation for 3d solids" settings only applies to AutoCAD solids - exactly as it says.

If you are using solids, and 0,01 isn't enough, then set it lower (you might need to set your system to use 4 decimals). This is often the case when working in "meter".

Hope it helps.

[knmdk]

Thanks for response, PROH. Unfortunately I coudn't figure out how to set unit precision for "Maximum surface deviation of 3D solids" to something other than 0.0mm. Maybe you could point me where should I look for this setting? I've searched in Preferences and Units Setup - nothing.

However I've found a workaround that fixes precision for smoothing AutoCAD solids when importing to 3ds Max:

- I set everything to millimeters in Customize-Units Setup

- then in "AutoCAD DWG/DXF Import Options" dialog I set "Maximum surface deviation of 3D solids" to 0.1mm

- and (important!) I set the "Incoming file units" to "Centimeters" (instead of "Millimeters" which is default).

Setting last mentioned option to "Meters" makes drawing cylinders even smoother. Then you have to scale drawing to 1/10 (for Incoiming file units - Centimeters) or 1/100 (for Meters).

Since you're experienced user, PROH, probablyou you know another thing (not related). Do I have to make blocks in AutoCAD to be able to apply materials later in 3ds Max? Or there's a more convinient (and fast) way? If I don't create blocks all my solids are one object in 3ds Max (and I can't explode this object).

[PROH]

Hi. The control for decimals is here: Preference settings -> General tab -> Spinners -> Precision.

As you already found out, the "right" number depends on the units in both the ACAD file and the Max file. If you chose to do it the way you describe (which I think you shouldn't) then never ever scale on object level. It'll give you lots of problems later on with almost anything, including texturing. If you use the scale tool, only do it on sub object level. Do you need to scale the whole scene, then use the "Rescale World Units" utility (utilities -> more). But IMO, the best way is to set everything up correct - then there is no need of scaling, and the problems related to that.

No,you don't have to make Blocks out of everything, just select "Entity" instead of "Layer" in the importer, and you'll have everything separated.

Hope it helps.

[knmdk]

It certainly helped with Entities, thanks so much PROH. Silly to miss such important roll-out setting.

I totally understand what you're talking about setting up drawing units correctly. However once I set up Spinner Precision in Preferences to 3 decimal I still get only 0.1mm for "Maximum surface deviation for 3D solids" in "Import Options" window. If I type in 0.001mm - it just won't work. Moreover this if I enter "0.001mm" and then click to a different input box in "Import Options" - precision changes from 0.001mm back to 0.1mm. Should it be this way? In case it's important all my units are set to millimeters both in 3ds Max "Units Setup" and in AutoCAD's "Drawing Units".

For now after a quick testing I import my scene from AutoCAD to 3ds Max in Centimeters with "Maximum surface deviation for 3D solids" set to 0.1mm and "Generate coordinates for materials mapping". Then I scale down my scene using Uniform Scale Tool and "Edit - Transfom Type-In..." set to 1/10. Materials seem to apply correctly after that.

I guess I'm set in case there's no way to get precision of 0.01mm (for "Maximum surface deviation for 3D solids").

[PROH]

Hi. Hmmm... very interesting. Never ran in to this problem before, but after checking, I see that you are right. There is a build in limit at 0,1mm. I understand your need for a workaround, but the one you're using will give you lots of problems, because of the scale tool. I'll suggest a "cleaner" and easier workaround to get 0,01 deviation, when importing DWG files in mm:

1) Set both unit systems in Max to "cm" (System and Display)
2) In the DWG importer uncheck "Rescale"
3) After import, set both unit system in Max back to "mm"

Now everything should be correct without any scaling.

PS - Be very careful with the scaling tool. Although it's a common practice for CAD users to scale in every situation, it's a bad habit that's giving you all kinds of problems in Max. Just take a look earlier posts at this forum.

Hope it helps.

[knmdk]

After diving deeper into woderful world of 3ds Max I've got a couple of tips for anyone facing model scaling/smoothing issues after importing from DWG.

Firstly you should probably try exporting your AutoCAD to FBX and then apply Turbosmooth modifier to all objects (inside 3ds Max). If your model isn't really complicated it'll work nicely. And you can tweak any problemmatic objects later inside 3ds Max anytime later on. Beware you'll loose all object ID info if you'll use FBX (and all AutoCAD blocks will be separate objects instead of instances in 3ds Max).

Secondly if you really need to import your model as a DWG (in case model is complicated and you want to save block IDs) you can set your 3ds Max units to Millimeters, then two ways:

1. Import your DWG (which should be in mm as well) setting curve steps to 100 and maximum surface deviation for 3d solids to 0.1 mm (in the import dialog window). Once imported apply Turbosmooth to all objects. They're gonna be smooth as you're used to in AutoCAD.

2. Import your DWG (in mm) but tick Rescale in import dialog window then set incoming file units to centimeters. Remember to  set curve steps to 100 and maximum surface deviation for 3d solids to 0.1 mm. Then you have to deal with scaling which is going to be 10x times larger that it should. But because 3ds Max works differently with scaling tool if you'll just select all imported objects then right-click Scale tool button and set scaling to 10% you will have problem. All textures (once you apply them) will be off 10x times. So you have to:

- select all imported objects

- apply XForm modifier

- hit + sign before XFrom in modifier stack (all objects still should be selected!)

- click on Gizmo

- then right-click Scale tool and set scaling to 10%

- viola now you can continue working and all textures will have right scale and mapping coordinates!

P.S. Don't forget to use UVW Map modifier once you apply your material.

[199995]

Hi
I'm new here. I have some question about importing 3d file(exactly 3d relief) to 3ds max 2016
I read this information above but I still have problems. 3Ds max doesn't open file. I know that settings are wrong but I don't know why and which is wrong. So what is the best way to open 3d relief cad file into 3ds max?
Thanks in advance

[PROH]

Hi. Never used 3D relief, but one possible cause could be that your dxf/dwg file isn't containing any compatible objects.

Maybe this can help:

https://knowledge.autodesk.com/support/artcam/troubleshooting/caas/discussion/t5/ArtCAM-Forum/Export...

Hope it helps

[pproestos]

yeap... of course you can refine anything in 3ds max. Personally after filelinked the autocad 

solids into 3ds max, then I assign a smooth modifier. Thanks for the inspiration guys... take care. 🙂

[tornadotodd2016]

I am a noob but learn quick. I downloaded a 3ds model from celestia of the space shuttle atlantis. It looked good in my 3d viewer but when I opened it in blender They cylinder tanks were very blocky. Not round and smooth but like many sided instead. So I opened it in 3d max and there were a lot of errors which I fixed a pick with poly convert and the model looks ok but not smooth and realistic like the shuttle and tanks should be. I also converted to obj and same result. I tried some smoothing in the modifier tab but I cant figure it out and I really want this to turn out realistic and nice. You guys all seem nice and helpful on here so I thought maybe someone would be so kind as to help out a noob. I am still learning all of the lingo. I would like to be able to fix this in max without reconverting because I had to already fix the errors in the model.

[Darwin33]

If your drawing is in meters I change units, both display and drawing in 3ds max to mm, then in autocad also in mm and import without rescale and setting 100 to smooth curves and  0,1 to deviation. Then in 3dsmax set up back units to meters, diplay and drawing. Seems to work fine for me and no need to rescale. I tried the turbo smooth but ruins my geometry.