topic Re: Holes in geomerty are correct in viewport. Non-existant in renders or export in 3ds Max Modeling Forum

Holes in geomerty are correct in viewport. Non-existant in renders or exports.

Anonymous — Fri, 27 Sep 2019 06:52:37 GMT

Hi all.
Not too sure what I've done to cause this issue.

My geometry is the plastic bezel around gauges in a car. I have put slots into pieces, so planes behind the bezel can be seen.

In the viewport I have slots and I can see and interact with the planes behind, through them. As soon as I render the area they are just flat and textured in the same material as the rest of the bezel as if they're not there at all. I have exported to FBX, in like with the game editor I am using and there are tiny slits, like a poly's normal is flipped and that's all that is visible. Previous exports were perfectly fine.

I started with the bezel, modeled boxes to the size and shape of the slots, used boolean to cut holes through and everything was working perfectly in viewport and render. I then converted to editable mesh to apply UVW Map for the texture and somewhere along the way messed the slots up.

I'm in the process of redoing the boolean holes with a slightly larger box than what's already in the viewport to see if that fixes it. If it does, i'd still like to know what I've done to cause it.

I am assuming the boolean to mesh convert is the cause.

Many thanks

Re: Holes in geomerty are correct in viewport. Non-existant in renders or export

leeminardi — Mon, 30 Sep 2019 14:25:49 GMT

"I'm in the process of redoing the boolean holes with a slightly larger box than what's already in the viewport to see if that fixes it. If it does, i'd still like to know what I've done to cause it".

When doing a Boolean subtract I think it is always a good strategy to have the object that is being subtracted not have a surface exactly flush with the object that it is being subtracted from. The theory of Boolean operations requires regularization in such a case to avoid getting an infinitesimally thin surface. Max is usually successful in doing this but sometimes is not.

Re: Holes in geomerty are correct in viewport. Non-existant in renders or export

Anonymous — Mon, 30 Sep 2019 23:11:47 GMT

Hi again

I did repeat the boolean with slightly larger box for the subtraction over top of the first subtraction. Just scaled up my original boxed for the subtraction by 0.002m.

It came out as expecting. Perfect holes in viewport again and importantly, holes in renders and export.

Converted to editable mesh after and it did the same thing. Visible holes in viewport, nothing in renders or export.

If I converted to editable poly after doing the subtraction all is well.

Not sure if that's intentional or a bug with Max or my geometry. But conversion to editable poly after the boolean seems to retain all geometry information.

Re: Holes in geomerty are correct in viewport. Non-existant in renders or export

leeminardi — Mon, 30 Sep 2019 23:58:16 GMT

Can you post the file with the boxes you used for the Booleans?

Re: Holes in geomerty are correct in viewport. Non-existant in renders or export

Anonymous — Tue, 01 Oct 2019 00:14:16 GMT

Unfortunately not what I had. I've near finished with the entirety of what I was doing so all the boxes are deleted at this point.

My process was to take the bezel object. (editable mesh originally)

Set view to front, orthographic so it was flat and even.

Create a plane, 1x1 segments to the size I needed, convert to mesh, and grab vertex's to pull 1 corner out and pull 1 in to give it the slanted sides, but keep horizontal top and bottom.

Shell the mesh converted plane to make it into a box.

Clone the shell for each hole and position the other 13. 14 including the original.

Select the 14 shells, and the bezel and boolean subtract the shells from the bezel.

Delete the shells.

Convert bezel to editable poly.

Re: Holes in geomerty are correct in viewport. Non-existant in renders or export

leeminardi — Tue, 01 Oct 2019 00:21:32 GMT

Rather than creating a plane, 1x1 segments it might have been better to use a box, convert it to an editable mesh (or poly) and manipulate the vertices or edges to get the slanted sides needed. Also, I would not have scaled the boxes without doing a reset transform afterwards if I am expecting good results from a Boolean. Scaling often causes problems.

Re: Holes in geomerty are correct in viewport. Non-existant in renders or export

Anonymous — Tue, 01 Oct 2019 00:29:15 GMT

I was thinking that as I was typing it. Forget the plane and go straight to the box I needed anyway.

Coming from Sketchup, creating a plane and extruding is standard procedure.

Thanks for the info on scaling, seems like it could be a wee trap.

And thank you for running though what I had done to figure it out.