Strange render problem with a glass bottle

[OzBoz]

I'm trying to model a glass bottle and all edges are straight/vertical but it seems wavy. Not sure if it's the model or something with the material. Maybe someone can help me out.. to make it clear what I mean look at the picture. Thanks in advance!



btw. I use the standard clear glass material for now.

[TqM]

Re: Strange render problem with a glass bottle

it is most likely the model. Turn on hidden lines and see if the cylinder lines are matching up with the lines on the render. if it is the model then methods of fixing it include soften/smoothing, which doesn't always work very well. or you can make it again and make sure the form doesn't fragment, or make it again and except this time when you have the curves before extruding them or however you created the form, divide them to as high a number as possible. I do this as a safeguard generally.

!!!Oh also there is a bug in sketch up (im not sure if this is unique to me or not), where creating a tube (via the plugin 'tube along path' or the follow line ), where the direction in which you draw the original pathline has an effect on the outcome, sometimes creating a poly'd form instead of a smooth one. (i'm guessing this is more likely your issue).
Hope something in there helped.

[OzBoz]

Re: Strange render problem with a glass bottle

Thank you for your reply. I'm not sure what can be wrong with the model, like if things are maybe 'twisted' I think you can expect such render outcomes. But now I got no real explanation for it.

I made some screenshots of the model and the weird thing is that although hidden geometry doesn't show diagonal lines you can see them very faint in the bottom image (with the red line). Think that is causing the weird render but I don't know how I solve them and make them dissapear.

[TqM]

Re: Strange render problem with a glass bottle

Yes those would normally be subdivision lines on the geometry, I am not sure why it is not showing them. My only solution to you is to remodel it with even more smoothness. I'm not sure how you modeled it previously but in actually all circular forms are an infinite number of straight lines, so really your model is just showing a lack of smoothness on the curve, so try and remodel it with more detail on the curvature. Give it a try if you can.

May I ask what the final use of the bottle is? If you are planning on putting something like a label on it then this effect you have going might look good.

[Jackson_cg]

Re: Strange render problem with a glass bottle

There's nothing wrong with the amount of detail on that bottle- I use way models with much lower poly counts all the time without problems and high poly props will kill SU in no time.

One thing to try is explode the bottle group, remove smoothing, apply the glass material directly to the geometry and then re-group it and apply smoothing again.

If that doesn't work can you post a link to the bottle and I'll can take a look at it for you.

[OzBoz]

Re: Strange render problem with a glass bottle

If that doesn't work can you post a link to the bottle and I'll can take a look at it for you.

Thank you for your offer. I did found out what causes the ripple effect. The long vertical lines/edges were not one line but three. That shoudn't make a difference because they are all vertical with the blue axe. But after I changed it SU didn't show the strange triangles and V-ray rendered it well.

Bad thing is now the inside of the bottle has the same thing but well.. it's less obvious and too much work to change it.. if I feel like it I might take another look at it. Wouldn't be much work with a round bottle but this one is bit odd shaped with a bit of a flat side.

Result for now:

[Jackson_cg]

Re: Strange render problem with a glass bottle

Glad you found a solution... for the outer face at least.

BTW, there's an extremely fast and easy way to rebuild any bottle/drinking glass from an existing dodgy model: just create a vertical section plane through your bottle model and explode all. Redraw any line on the section plane so it will become a closed face. Draw a vertical line from the centre point of the inside face of the base of the bottle to the centre point of the bottom face of the base so you now have two halves of the section though the bottle and delete one half so you're left with a roughly L-shaped face showing the profile of the bottle. Now just draw a circle (number of segments depends on what you're going to use the bottle for- closeups or background bar/wine cellar props) from any centre point until it meets the L-shaped face and use SU's "Follow Me" path tool to extrude the section around the circle. Sounds like a long process, but it takes seconds to do and is an extremely efficient way to fix bad models and to design lathe-type objects like glasses, vases, etc.

Nice materials and studio environment BTW.

[OzBoz]

Re: Strange render problem with a glass bottle

Glad you found a solution... for the outer face at least.

Thanks again for the reply... i'm pretty much a 3D noob at least render wise. But the nasty part of this bottle is that it ain't round. So what I did was create half of a bottle and scale some parts of it to get the right shape and measurements. Rendering glass takes a lot of time I notice and it's been some work to get things set up right. Need some 8 core computers here

Render below is a 30 minute render but well.. looks pretty ok. I think I got rid of most weird artifacts but not all.

About the materials and setting.. think it's so hard to get the right picture. But I've someting in my mind and try to get things right. But with glass stuff it takes a while.

[Jackson_cg]

Re: Strange render problem with a glass bottle

Same principle applies for oval/square/organic forms- in fact any shape which can be formed by extruding a profile along a path, like the Aalto vase I modelled below. Just draw the circle as I described above, then distort it using the scale tool to make an oval before using the "Follow Me" tool. This method only runs into problems when the profile itself changes along the path, but it'd definitely work for your bottle above.

[TqM]

Re: Strange render problem with a glass bottle

Good technique Jackson. I like. Thanks.

[OzBoz]

Re: Strange render problem with a glass bottle

Same principle applies for oval/square/organic forms- in fact any shape which can be formed by extruding a profile along a path, like the Aalto vase I modelled below. Just draw the circle as I described above, then distort it using the scale tool to make an oval before using the "Follow Me" tool. This method only runs into problems when the profile itself changes along the path, but it'd definitely work for your bottle above.

I think I did my bottle the same way. But since some parts are flattened I wasn't sure about the best way to get it done. Like the bottom of the bottle is a pretty oval shapen with even a bit flattened sides but when you use follow a path you will also have a weird shaped 'neck' for the bottle and that should be round again.

What I now did was creating a half bottle around a normal circle. Then I selected parts of it and use scale to make it oval. After that I extruded some parts to get the flattened part of the oval.

Not sure if it can be done easier think I did it using your described method only I had to be a little creative because the shape of the bottle.

[Jackson_cg]

Re: Strange render problem with a glass bottle

Ahhh.... very good point about the neck of the bottle being round- I didn't think of that. I guess the easiest way to do it from scratch would be to do the "Follow Me" trick for the oval part of the bottle, then scale the top edges of it so that they are round to match the neck of the bottle. Certainly more to this model than it seems at first!