Author Topic: How to improve output quality  (Read 4460 times)

I'm in the process of learning how to use Substance Designer and I am trying a texture a window with a wooden frame. The object is for Second Life, thus I can only use diffuse, normal and specular maps.

So, what I am doing is to blend AO and curvature maps with the diffuse, as you can see in the graph...

The problem is that when I blend these maps together the diffuse output is too dark. What filter can I use to make the image lighter?

Also, do you have any suggestion to improve the graph?

you could  add a "levels" node  to get more granular control before the gradient.  I've also done adjustments using the contrast/luminosity filter for more dramatic changes.

also, may want to make sure you are using the same size images in a blend as your intended output to avoid to much aliasing...  down scaling the 4K to 512k would cause a lot of.. messiness in quality.

hope that helps.

[edit]

also, not sure how you blend the AO in, but I will use a multiply and adjust accordingly...  same for the curvature (but I don't blend curvature with diffuse).
Last Edit: March 23, 2014, 07:47:38 am

Thank you for the tips, Walker.

I use multiply for both the AO and curvature blends. Curious about your comment that you don't blend the curvature with the diffuse. You don't because you don't need it or because it's bad practice?

Thank you for the tips, Walker.

I use multiply for both the AO and curvature blends. Curious about your comment that you don't blend the curvature with the diffuse. You don't because you don't need it or because it's bad practice?

The curvature map shows convexity/concavity. The most common use of your curvature map is to use as a mask for working on the exposed convex edges - edge wear, scratches, etc.

concavity can be used for dirt buildup, etc.

there's nothing wrong with using your curvature in your diffuse, but it might look funny. It's not really for lighting, that's AO. Most of the time you want to use it as a mask, not directly blended into your diffuse.


Plug your blue diffuse colour into the "background" input connector on your Blend Nodes throughout your graph.  Currently you seem to be using your diffuse colour as the additive when you really want it around the other way, ie add AO and Curvature to your diffuse blue main colour so these should be connected to the "foreground" input.

But as Phil said, the Curvature is better used to to create your Specular output in combination with a Levels Node connected after rather than as an additive to your Diffuse.

Also, in your Blend Node settings, change the Blend Mode to something like Add (Linear Dodge) if you need to brighten your Diffuse.   

Thank you for all the tips, guys. I really should do this more often.

@Phil, @artzfx: my intent with using a curvature map was indeed to add edge wear to a low-poly model. I also thought the curvature map helped simulating curved edges but apparently I misunderstood its use. I'll look into this. Can anyone point me to a good example of how to use a curvature map?

@artzfx: thank you for the tip on using the background connector. I have also tried to switch the blend node to add but the result was too light. And, since I seem to be using a curvature map the wrong way, I may not even need to use a Levels node. Without the curvature map the output is definitely lighter.

Any additional feedback on improving my graph is welcome.

As Phil said the curvature map tells you if that pixel is concave, convex for flat. The curvature is flat when the pixel is grey. When its white the pixel is convex, when black concave. Generally you have edge wear where its convex and grime buildup where its black.

Using a curvature map with a blend mode set to multiply is incorrect usage of a curvature map. If you have a flat (grey texture) curvature map, multiplying it with the diffuse will just darken the diffuse by 50% (diffuse * 128/255).

SD has a bunch of different blend nodes in the library. Library->Filters->Blending. You can use the overlay node to have it darken when the curvature is black, brighten when the curvature is white and do nothing when the curvature is grey. It behaves exactly like the photoshop overlay blending mode. This is a simplified use of a curvature map.

A better use is using it as a mask. You can use a levels node to convert the curvature into a concavity or convexity mask to use for more complex edge wear or grime buildup.



Thank you, jan. I am trying to find additional details on how to use the curvature map in one of the available videos. I wish there was some written documentation on how to use this stuff.

Try the Pod tutorial Part 7 http://www.allegorithmic.com/community/tutorials or the Cymourai tutorial Part 4 http://www.allegorithmic.com/community/tutorials

He bakes the curvature map and shows how to use them, however you can also use the Curvature Node in the SD Library if not choosing to bake one.

EDIT:  Here is another older SD2.5 tute from the Allegorithmic guys that explains curvature map use http://www.youtube.com/watch?v=6TU7LKX3IWg
Last Edit: March 25, 2014, 07:19:58 am

Hi Indigo,

As artzfx said, you should use your main input (color of the mesh) in the background input of the blend, and the "additional" effect in the foreground (top) input . This way, you'll have the possibility to adjust the intensity of the effect using the "Opacity" parameter of the blend.

You can use your curvature in a blend node, with the blending mode set on "add sub". With a low value for the opacity you should have something correct. You can also modify the curvature before the blending (for example using a "warp" node to add variations).

Another way to use the curvature map is to use it as an input in a filter. We provide several filters (based on a curvature input) in the library in the "Mesh Adaptive" group. For example: "Edge Speckle", "Edge Dirt", "Edge Notch" or "Edge Damages".
Lead technical artist
gaetan.lassagne@allegorithmic.com

Ah! Thanks so much artzfx for the links to the right videos. I really needed that.

Interesting tips, Gaetan. Thank you, I'll try your suggestions.

So, I have followed the suggestions you guys kindly provided and I am getting better results. I have blended the curvature map with an Add Sub mode and reduced the opacity as Gaetan suggested. I also tried other filters but the result wasn't what I wanted.

I have also blended the curvature map with the specular output of the dyed wood material I am using. I suppose this should be the proper approach. I have some artifacts that I need to correct in the normal map but other than that the results are pretty good. I am particularly pleased with the wood texture.

Further suggestions are welcome.