Adding grime to obj models

Started by Djb3000, June 01, 2014, 03:48:00 PM

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Djb3000

Hi,
I have been working on an image with an obj model made in Blender.

What is the best way to put dust and scratches etc on the windscreen (Shield?)? I tried a uv map in Blender but it doesn't show as I have zero opacity on the windscreen shader. Do I use an image map shader as a mask?

Hope somebody can help.... I'm sure this has an easy solution.  8)

TheBadger

QuoteI'm sure this has an easy solution

;D  ;D  ;D



Sorry, I know thats not helpful.
It has been eaten.

TheBadger

#2
OK,

So actually there are several threads on this topic. The thing is they all seem to present different issues on this topic. So you may have problems based on the exact result you want. But here is a tut by dandelo that you should start with.

The glass must be its own object. That is to say, the car body and the wind shield should not be one mesh.

http://www.planetside.co.uk/forums/index.php?PHPSESSID=fdcc073f924ae32981fa0b1f088ebecd&topic=15018.0 scroll down a little and look for the insect.

here is some other on topic links
http://www.planetside.co.uk/forums/index.php/topic,15003.msg146044.html#msg146044
It has been eaten.

Djb3000

Thanks. I will experiment with these.  8)

Djb3000

I cant get this ti work at all. Ive tried with the method below on the separate windscreen mesh. but i just get either nothing with the opacity on the windscreen shader set to 0 and black with it set to 1. The water shader doesn't seem to have any effect at all.  :(

Kadri

#5

Does the windscreen mesh have a UV map?
Not sure but at first your problem looks like UV mapping related.Anyway...
Use that UV map as the "Projection type" in the Image map shader.
Be sure that you have the "Transparency" at 0.95 or so in the "Water shader" node.
And the "Decay distance" at 2e+008 (it might be lower or higher then this)  or so in the "Sub-surface" tab.

If you have done all of those and still get not the effect you want
one of the possible problems could be that you have to play with 2 settings especially;
"Decay distance" in the water node "Sub-surface" tab and the "Colour" tab in the image shader
You may have to fine tune the image appearance with the "Convert to linear" and then playing
with the "Conversion gamma"  value in the "Colour" tab in the image shader.
Small values like  0.1 will be more transparent and big values like 10 will look black.


bobbystahr

try this thread below, I've put a .rar of a project there for you to try. It may be what you need to try.

http://www.planetside.co.uk/forums/index.php/topic,18342.msg178034.html#msg178034
something borrowed,
something Blue.
Ring out the Old.
Bring in the New
Bobby Stahr, Paracosmologist

Djb3000

Wahey! It works.  :)

Thanks for the brilliant help and guidance.

One last question though, what sort of number is - 2e+008? I have no idea what it means.

Thanks again

AC5LT43R

Surely it would be much easier to render the car separately? I'm not sure how things work in Blender exactly, but if I were doing this in Max (and I plan on doing so soon), I'd create a spherical map from Terragen and then use it to light the car in Max, render the car in Max and then render the BG in Terragen, then comp the two together in Photoshop/AE whatever your choice of package is.

A quick search on Google shows me this tutorial for putting scratches/dirt on glass http://www.blendernation.com/2011/11/14/creating-a-scratched-glass-bottle-with-cycles/

inkydigit

hi zapatista  8)
for some other ways maybe, here is a link to klas's glass (scroll down page a bit for the link), I have used it many times, only downside is having to separate the glass parts of the object and load them separately... you could probably add a power fractal on top of the water shader to add some dust etc?
and 2e+008 is a very large  number 2+ 8 zeros I think... and minus would be very small?
someone will have a better answer I am sure!
cheers
Jason


bobbystahr

Quote from: AC5LT43R on June 04, 2014, 08:47:55 AM
Surely it would be much easier to render the car separately? I'm not sure how things work in Blender exactly, but if I were doing this in Max (and I plan on doing so soon), I'd create a spherical map from Terragen and then use it to light the car in Max, render the car in Max and then render the BG in Terragen, then comp the two together in Photoshop/AE whatever your choice of package is.

A quick search on Google shows me this tutorial for putting scratches/dirt on glass http://www.blendernation.com/2011/11/14/creating-a-scratched-glass-bottle-with-cycles/


I think the question was ; "How do you do this  IN  TG3?" AC5LT43R, not blender or Max.
something borrowed,
something Blue.
Ring out the Old.
Bring in the New
Bobby Stahr, Paracosmologist

Djb3000

Thanks inkydigit, but I cant see the link.

Also thanks for advice AC5LT43R. I did consider using Blender for textures etc, but I wanted to work mainly in Terragen for this. I'm still quite new to these techniques and as landscape creation was my initial interest I didn't want to be sidetracked too far into Blender. Hope this makes sense and thanks again for your suggestion.  8)