[substance designer] How can I apply dirt to a complicated shape using the nodes?

oraeles77

Hello.

I have been using SD for a long time so this isnt a begineer question, for this example I've used a blender square to explain my question.

If you look at the image you will see what Im looking for, ideally a node, which will apply dirt, lower to the ground= more dirt, higher from the ground=less dirt. I assume some sort of position map/world space normal thing would be necessary, however I can't find a node which quite does it.

the dirt gradient sort of sums up the type of image I'd like to see on each face, however I would also like the textures to be seamless, so I assume I should also use a triplanular node?

any advice would be welcome.

oraeles77

Here are some things I've just tried. none of them quite hit the mark, but Im using that top to bottom node. with triplanular for seamlessness.

Clark Coots

Give this a try, I've used it for Rock models to apply dirt at the bottom. Blend node at end is "Subtract". Histogram Scan is optional for more control over gradient. Cloud 2 plus other noises can be whatever you want to break up the linear gradient.

oraeles77

Clark Coots said:

Give this a try, I've used it for Rock models to apply dirt at the bottom. Blend node at end is "Subtract". Histogram Scan is optional for more control over gradient. Cloud 2 plus other noises can be whatever you want to break up the linear gradient.

hey clark, thank you so much for giving the  time to reply, I will give it a try now. by the way, im surprised this isnt already a node!

oraeles77

Hey Clark Coots, I tried what you said, I had to add a top to bottom node, to blank out some of the tallest parts of the geometry, but its not quite right, i will keep at it, thanks for your advice.

Clark Coots

No problem, let me know how it goes.

When you used the Dirt node did you have "Use Tri Planar" set to True?

poopipe

If you feed the position and world space normal maps into rgb split nodes you can extract masks for whichever direction you want and then muck around with them

oraeles77

Clark Coots said:

No problem, let me know how it goes.

When you used the Dirt node did you have "Use Tri Planar" set to True?

yeah , i played around with that but it didnt exactly help out the main problem.

oraeles77

poopipe said:

If you feed the position and world space normal maps into rgb split nodes you can extract masks for whichever direction you want and then muck around with them

i sort of understand, but if you have a link to explain it a bit it would help a lot!

poopipe

The red channel is X, green Y and blue Z 

In the position maps they'll be simple gradients, the wsn map is what direction each pixel is facing in. 

You can work out what they do by simply viewing each channel separately on your model. 

oraeles77

poopipe said:

The red channel is X, green Y and blue Z 

In the position maps they'll be simple gradients, the wsn map is what direction each pixel is facing in. 

You can work out what they do by simply viewing each channel separately on your model. 

thanks i will look into that later this week.