displacement triangles appearing on imported geometry

[analogueWay]

Would you like to post a sample scene (maybe something like just the walls that you showed in the sample rendering)?

I haven't run into this problem yet, but I am sure that it's in my future as I get a lot of geometry from our architects.

-Jeremy

edit:: I didn't realize the thread was this old. You can forget this post. I'll just deal with the AutoCAD/displacement issue on my own when I get there.

[tonymacdonald]

gotta love archicad!

[paulison]

tony do you have any problems with ArchiCAD? Ive had no real problems except for when i export a mesh with smoothing which isnt interpreted correctly in max.

Im guessing that similar to the original posters problem (in AutoCAD but no doubt a similar thing), this can be solved by adding another smooth modifier and just setting it to auto.

Oh yeah ive also been using a really good utility called polygon cruncher which is quite good at reducing anything heavy in polygons exported from ArchiCAD. Also converting to editable poly before modifying works well for me.

So you think stick to ArchiCAD? Ive worked with people tell me its trash and refuse to use it yet I find the excessive polygon/verticies arnt really a problem after a bit of tweaking in viz/max. Big scenes render great in vray!

[dapeter]

I use displacement all the time on AutoCAD files imported into viz and max. AutoCAD doesn't really go by the whole polygonal thing, so if you have an ADT wall with a window in it the vertices cutting the hole in the wall for the window do not get connected to the corners of the overall wall polygon.

All you have to do is add a subdivision modifier (I usually subdivide to 3 feet or so) and then the vraydisplacement modifier. The extra tri's the subdivide operator created joins the window verticies to the wall corner verticies. I've had no problems using this technique with any geometry I've imported - in fact my current project has a ton of multi-sub displaced walls with brick, stone, and stucco - no problems as long as I use the subdivide modifier.

[tonymacdonald]

I have found the 3ds export from ArchiCAD 9 does apply a smoothing to terrains. To remove it i select the polygon and remove the smoothing and its fine. I hadnt had that problem before version 9.

Archicad is great peice of software for Architectural modelling. The major benifit over AutoCAD is that ArchiCAD has no limitations modifying the model geometry. Anything can be modified easily and quickly, slabs, walls, windows, terrains can all be modified without any exploding and remodelling. ArchiCAD is also fast due to its parametric capabilities and extensive window, door and object libs. Like you say the polygon counts arnt an issue for me either. Polygons are more an issue when creating detailed modelled trees in treepro for me. one tree can be larger than an entire archicad model. There are alot of companies in Sydney using ArchiCAD as there main 3d modelling application for Architectural work due mainly to ArchiCAD's speed in modelling and flexibility in modifying. Check out some of the old 3d comps on the net (3dshootout's) ArchiCAD has always been 1st or in the top 3. I have to say VRAY just seems to eat up the poygon count anyway.

[dennis]

as been said....put a subdivide modifier on it...it has done wonders for me in same situations.

[sjmoir]

Old topic I know but useful. I found the subdivide (Radiosity Modifiers) worked for me too, on a large closed spline shape extruded to represent lawn areas.

[Rolojero]

Hello i tried some of the tips you people post tks a lot!! but none work apparently has to be with the way autocad construct solids and i think the only solution is to beggin to model in max... at least those parts we want displace

But IMPORTANT i noticed this only happens with solids a little more complex than standard, the image below is an autocad region with a circle substracted, but the same material into a rectangle extruded works perfectly fine



Tks a lot for coments but if you come along with another posible solution please post it!!

Pd.- The post i found it searching for autocad displacement and neither has noticed had so many time in the freezer!!!

[instinct]

mind posting this grass piece ? i´d like to take a look at your issues as we had similar with cad imports.

Thorsten

[Da_elf]

what do you mean workds fine? i can still see triangles there

[percydaman]

what do you mean workds fine? i can still see triangles there

reread this portion.

but the same material into a rectangle extruded works perfectly fine

[dapeter]

It doesn't even look like you subdivided the face using the subdivide modifier in max/viz.

If you did, and you still get triangular artifacts, I've found that adding an editpoly modifier and 'slicing' some new vertexes in around the holes and openings, then subdividing that resulting mesh, can get rid of some of the funny tri's AutoCAD objects and booleans can create.

[Rolojero]

Hello, how are you friends!!

The triangles looks to me like if some of them were positive and other negative i mean if displace work upside in some and down to others and also the displace looks lige if it get different distribution of the bitmap in every triangle, i try standard mat two sided and did't fix it, i'm looking for a way to consider a autocad object as a whole and not a composition of planes (triangles very bad achieved) and maybe that can be the solution... is't there a way to weld all the planes into one?

Tks a lot fot replies

Instinct: you want me to post a piece of grass you mean the map or the scene?

Saludos desde los Cabos!!

[Da_elf]

oooooh my bad. it looked like he was compairing one image as the good one and one the bad. now i see he was showing that its just as bad no matter what you do.

[fabrizio]

If I export a solid with a dimension<0.5 cm in dwg from rhino, I have a bad result in max6+vray 1.47. (and without displacement)

fabrizio