Low poly shapes

Hi folks,

I’m really confused about something, I’ve been trying to follow along with Dave Reed’s 3D interior development videos on YouTube because I’ve wanted to work on interiors & furniture etc for a while (the results he’s getting look amazing, so check the videos out if you haven’t seen them)

But I’ve fallen at the first hurdle, so to begin he brings in a cube, sized as a flattish rectangle (imagine one piece of board used in a set of flat pack furniture) initially a really basic box with only 8 vertices & quickly finds out that it looks really wonky when lit, I’ve noticed this myself many times, I don’t really understand why, I mean a cube is 6 sides, so I don’t understand why you can’t use a simple cube, maybe something to do with resolution & how shadows are created? Anyway, then he brings in another cube like this;

Post subdivision - 2
Linear subdivision - checked

Division X - 82
Division Y - 2
Division Z - 32

Size X - 2.57
Size Y - 0.0773
Size X - 1.0

Then he validates it, then voxel remeshes at 385. The box is then 126k vertices. Then he uses a modified smooth tool to slightly round the edges, which then means he can decimate it all the way down to 63 vertices before it starts to look wonky if he decimates it again.

So I’ve followed along & I just can’t replicate this, I can just about decimate down to 990 before it starts to look distorted. So I’m stuck there. Obviously there’s a big advantage to being able to model walls, cabinets, doors etc with only 63v as a starting point instead of 990v, I just can’t work out where I’m going wrong.

I realise non of this will make much sense if you haven’t seen the videos, so if anyone who hasn’t seen them has any tips for how to get low poly shapes which you can colour & light realistically I’d love to hear them.

In the decimation tool you have to work with the “uniform faces” slider. That one tells decimate to produce x % of all triangles to have the same size. I just tried your example and by setting this value to 0, I could even go down to 32 verts without losing shape. Of course - no rounded edges at this point, and the topology is a mess.
I also do not get, why Dave would go through all these steps. I tried with with a standard box and could decimate down to 53 verts.
Then again - maybe a box with just reduced resolution would do the trick too? I mean if 63 verts that are spread all over the place work, 200-something with clean vert distribution should as well?

Also : Nomad is awesome at handling massive amounts of verts. So if your board has some hundred verts it won’t make Nomad break a sweat, even if you use 1000 of these boards in your scene.

Thanks for the response. I should have explained I also followed his decimation sliders which do have the uniform faces at 0, initially my settings were different & I thought that was the problem, setting that to zero, unchecking preserve painting & setting target triangles to 50% did improve things, but still only to 900v, there must be something else I’m missing.

I’m not sure why he’s using all these steps either, possibly for the rounded edges? which do look nicer than pin sharp edges I think, the final result looks great. Though at this point I’d be happy to achieve the standard box at 53v the way you’ve done it, obviously the underlying topology being clean is better in the end, but I can’t even get that to work right now :man_facepalming: Could you walk me through how you got your standard box down to 53?

I guess I want to keep the boards down low because I want to save as much space as possible for characters, which will obviously be much more detailed.

Well, there’s not much to it. I add a box, validate it and scale it, so it looks like a board. Then I start decimating, until I hit 53 verts. You can see the settings in the screenshot. It’s from the web demo. I did not change any settings there.

Btw : You can get the round edges without any smooth tool just by using “post subdivision” with “linear subdivision” unchecked. You then need to play around with the subdivision level and the actual division in order to get the “roundness” you want. Of course this comes with lots of extra verts.

You can can scale that one down to 59 verts with round edges intact.

And “target triangles” tells Nomad, how far it should decimate. Decimation converts quads into triangles. The percentage says by how much you want to reduce the vertex count. So as you progress with your decimation, you might wanna experiment a little by raising this slider. So if you are at 500 verts - instead of going down to 250 verts (50%), you might wann go to 375 (75%) and see how that looks.
If you have a full quad mesh and set “target triangles” to 100%, Nomad will simply turn all quads into triangles without reducing the vertex count at all.

Thanks :+1: this really is a mystery, as soon as I hit decimate on a standard box it starts degrading very obviously :thinking: the only difference I can see on your screenshots is you have preserve painting checked, so I’ll try that as soon as I can :slightly_smiling_face:

Re: post subdivision without linear subdivision checked, yep I knew that but yeah was drawn to his method for the low polycount

That degradation - is that, because you have smooth shading on? Check the “cog”-menu. With smooth shading on as soon as I decimate a standard box, I see nasy artifacts. However when I turn smooth shading off, the geometry looks just fine.

However, when I add a box with post-subdidvion rounded corners I don’t see any artifacts when decimated down to 88 AND smooth shading on:

I think, the mystery lies in the rounded edges. With “uniform faces” set to 0, Nomad can decimate the geometry in a way, that’s “good” for “smooth shading”. However sharp edges from a standard box will be affected immediately (visually) by “smooth shading”.

Maybe Stéphane can explain, why this happens. I don’t have the technological knowledge.

Really appreciate all your efforts thanks :+1: I’ve tried smooth shading off & on, it did make a difference but not much of one :man_shrugging:

I’ll let you know how I get on trying your suggestions as soon as I get chance

So bizarre. I’ve managed to replicate your decimated box without rounded edges (down to 96) with smooth shading off.

As soon as I try a rounded edge box of the same size (rounded by post subdivision - 2) I just can’t decimate below 4 figures, with or without smooth shading on. Something else I notice about the box rounded in this way, even before decimation, if I have smooth shading off, the curves on the edges are slightly pixelated instead of smooth.

Think I’m going to try doing the same thing on the web demo, if that works maybe delete nomad from my iPad & download again fresh :man_shrugging:

Nomad sculpt is actually a sculpting app…
What Dave does is not practical for furniture. The decimate thing he got from me just a few days ago in combination with my Round All brush, now he wants to decimate everything. Furniture like this should be created more like in these videos or use CAD software.
Part 1: Nomad Sculpt - Cabinets & Shelves 1 - (Furniture) (V1.71 -17.1.2023) - YouTube
Part 2: Nomad Sculpt - Cabinets & Shelves 2 - (Furniture - Doors) (V1.71 -17.1.2023) - YouTube

How to decimate reasonably correctly:

Translated with DeepL Translate: The world's most accurate translator (free version)

Don’t delete or reinstall Nomad, it doesn’t improve anything - you can reset the settings within the app. - that is a statement from the developer Stephan.

Thanks :+1:

I do appreciate that this isn’t what nomad is for & if I had access to all the different apps/ programs to do everything properly that would be great. Unfortunately I don’t & Dave is getting great results, at least visually, which for what I want to achieve at the moment, is what matters most to me. I’m not looking to actually make real life furniture using nomad, I’m interested in creating 3D illustrations using it.

I’ll definitely check out your videos later though thanks

The point is to have fun sculpting and for that Dave’s videos are absolutely great.
But if you want to know how to do some things in a minute instead of 1 hour, then you should also look at other tutorials (:wink: it does not have to be mine).
Dave will understand the fun, but you were confused yourself because of the cube he used…
Have fun with your sculpts.

Disable smooth shading for this shape if you want flat shading.

Smooth shading doesn’t make any difference to the decimation, it’s only visual.

There is a small regression to decimation the latest Nomad version but most of the time it should work fine Decimation Issue - #4 by RogerRoger

Otherwise maybe delete UVs if you have it, the decimation algorithm needs to keep UV seams relatively intact otherwise:

Thanks again :slightly_smiling_face: I actually started a while back with Glenn Southern’s tutorials, which I assume are more ‘correct’ & technically sound, I think I have seen some of yours too :+1:

I was just really impressed with some of the results Dave’s achieved recently & particularly with the rooms he’s done some things I’ve wanted to do for a while.

I guess it’s good to learn from as many places as possible, my problem is I quickly lose interest in one method & move on before I’ve learned properly :rofl::man_facepalming:

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Thanks for taking the time to help & congratulations on a fantastic app, I’m really enjoying using it, even if I’m not always using it correctly :sweat_smile::+1:

Agreed, he really nails the presentation/rendering part.

Ah that decimation issue video has also helped. If I decimate at 50% every time I still can’t decimate down as low as I’d like, but if I change the % to a much lower number just before it starts to look wobbly, it seems to work much better. So far I’ve managed to get my round edged board down to 115V & it still looks clean :slightly_smiling_face: