Facetted Object

Started by j meyer, March 07, 2011, 10:26:29 am

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j meyer

Hi there,
while testing something texturing objects i came across this one.
Using a node set up like this
[attachimg=#]
i found that as soon as you reduce coverage (surface layer) you get
that facetted look.(smooth normals still on)
[attachimg=#]
It seems to be caused by distort normal in conjunction with warping
of the fractal break up shader and shows up also when the blending
shader input is used.
The above goes for the distribution shader too.

freelancah

Im guessing this is because the smooth normals does not affect the polygons itself, only how light is calculated on them. The polygons are what bounds the fractal so thus this polygonal clipping happens. If you would subdivide the cube more you might get away with no polygonal clipping.

I'm guessing here, perhaps someone else can explain it better

j meyer

Thanks freelancah,but i guess not.
[attachimg=#]
This is just without distort normal and warping.

j meyer

Any official opinion would be appreciated. ;)

j meyer

Hello,Planetside do you read me?

dandelO

I've never actually seen any difference using smooth normals checked or unchecked for objects in TG, other than the internal rock object, it works very well for that.
I'm not sure it even modifies an imported object at all. I might be wrong, though.
Importing a faceted object into Vue(for example) and using object smoothing actually really cleans up the surface creases, many times I've done this and been disappointed in the same object in Terragen and needed to subdivide the object again.
Checking 'smooth normals' in TG, I've not noticed any difference. I must test it again myself to re-confirm this, though...

Sorry, I'm of no help here, just thought I'd post my own findings.

j meyer

Thanks Martin,but the problem has got nothing to do with smooth normals,
i just mentioned it in my first post to avoid answers like:do you have smooth
normals checked or something in that vein.Obviously a misleading mistake.
The problem is:if you use the above node set up and decrease the surface layers
coverage you'll get that facetted look as long as distort normal and warping on the
PF that is used for fractal break up are checked(which is the case by default).
I hope this cleared it up a bit.
Maybe someone could try if that is reproduceable on other machines,too.
If it is still not clear what i mean i can provide a tgd and the testcube.


dandelO

Sorry, full of shit, as usual. :\
Should probably just give up and stick to myself, at least I know what I'm talking about, even if I don't know what anyone else is! ;)

Night night! Hopefully you'll get a fix, sorry, J!

airflamesred

I'll have a look at this. Just one question (and I think its relevant) Is this obj uv mapped? I have had differing results with and without sensible uvs. I shall have a go with your node set up.

Oshyan

I'm told by Matt this may just be a fundamental limitation in how these shaders work when applied to objects. I'm not sure whether that means an accuracy issue, or what. But it didn't sound like it was easily resolved.

- Oshyan

j meyer

dandelO - No problem. ;)

airflamesred - the shown object is not uv mapped,but i first noticed the effect on an
at least partly uv mapped free car model,so...

Oshyan - thanks for the info,good to know that it's not due to my PC or myself.

airflamesred

Well don't ask me why but there is a noticable difference with the state of the uvs.
That probably doesn't help here though it depends on what you are trying to achieve. I gave up on this method of texturing a while ago (Oshyan seems to be confirming my suspicions) in favour of mesh painting. My terragen skills are poor at the best.

I couldn't reproduce the example you show but that would be dependant on any number of things (polys, seeds etc) I realise this doesn't help much but I'm not convinced there is a solution.

j meyer

Thanks airflamesred.
As far as i'm concerned the solution is to have distort normal and warping unchecked,
at least for non uv mapped objects.