Quick Tip: How to Make Easy Grunge in Blender
Andrew Prices shows how to add dirt to your renders.
You know when you move some furniture around there’s always a noticeably clean patch of carpet where the furniture used to be? That’s because dirt is everywhere, and it takes some serious elbow-grease to get anything as perfectly clean as most CG renders look.
It’s easy to add a lot of dirt everywhere, but that’s not how the real world works. We need to add dirt in specific places and make it look like it just naturally formed there. The texture map that does this is called a dirtmap.
There are many different types of dirt, too many to cover in one short video, so in this tutorial you’ll learn how to add the most common kind: Grunge.
Trickster! In a “quick tip” video for making easy grunge, the very last step is “overlay a grunge texture.” So to make easy grunge, you overlay grunge. Okay then! :)
Yeah, I agree…
Plus, for a “quick grunge”, baking AO seems tedious, wouldn’t it be quicker and more simple to use the pointiness?
Still, nice tip :)
there are advantages to baking and advantages to doing it live.
If your animating baking is a very good idea as the dirt distribution should remain static and not dependent on occlusion
The AO pass was to make the grunge exclusive to the cevises. The overlayed grunge was for a lighter (blanket) grunge that would cover the entire model.
Wow! Thank for quick tip
This may be nitpicking but Greg Zaal appears to have made this for Blender Guru, so “Andrew Prices shows how to” is not quite correct
You can get my glsl volume perlin noise here It doesn’t even require mapping:
http://www.blendswap.com/blends/view/79733
Cheer
This is a very wasteful way of doing this effect. Do the grunge in a texture mix not a shader mix.
Yeah, I would do it in texturing, too. For an object like this, I think texturing is the stronger way to go.
Though, this is only an example of the technique. I can see some use for this method, perhaps such as if you want to animate the effect, such as a time-lapse that shows dirt collecting on the metal or something.
I’m more of the mindset that options are nice. Options give leeway to problem-solving and innovation.
Indeed no harm pointing it out though
You should not need to bake for that (which implies UVs). Use the new pointiness geo attribute or use the OSL ao shader for blender to drive the mix. All procedural.
theres an OSL ao shader!!! that seriously made my day!
Glad I could help. I think i got it from here:
http://vadrouillegraphique.blogspot.de/2012/12/simple-osl-ambient-occlusion.html
It also does interesting other modes that could create worn edges, too (like the inverse of a dirtmap).
For wear maps the pointyness value is the way to go.
http://durknfred.blogspot.ie/2015/02/new-cycles-pointiness-attribute.html