Author Topic: Explanation on normal map artifacts?  (Read 2693 times)

Hey guys. I've noticed this in normal maps created in SD as well, but in this I'm in SP2. As you can see in the picture, there are those grid like lines showing up in the normal map. I created this just as an example by painting with the height channel with alphas that come with SP2 (Splash spots and Spray I think). And the normal map channel under the texture set panel is set to RGB16F so it should be 16 bit. Also the texture res is at 4k. So, normal map is 16 bit, texture is set to 4k, but those lines are still showing up for some reason. One theory I have is that the alpha textures being used to paint are not 16 bit or the sbsars in this case? So if anyone that knows more about how this works could explain this, I'd appreciate it!

Thanks! :D

hey, did you try to triangulate your mesh before to export?

I did. But that shouldn't matter as I'm painting this on a flat plane mesh with the minimum amount of tris (2)

do you mind sharing some of the files ?

Sure. I've included the spp file and the fbx used. I've left the res at 1024 in the file because it seems to do an alright job the lower the resolution is for some reason. So when you open the file, try upping the res from 1024 to 4096 first and you'll see what I'm talking about. It turns from smooth gradient to a pixel grid.

Got the same bug: just a question: how did you create the pattern at first ?

I honestly don't remember lol. But it was generally just using an alpha as the brush, then using a different alpha as an eraser and going back and forth. I want to say I was using the splash spots and spray alphas but I'm not sure. Might of been another alpha in there too. But the one in the attached spp is just that method above ^ with just the splash spots and spray alphas.

Well from what I can see, it may just come from the spray pattern which lacks definition at 4k

hmm. That gets me thinking about how SP and SD handle going back and forth between resolutions. Like if I import a premade bitmap into SD to use for a graph, say at 512, if the graph goes above 512 I assume it's doing something similar to what Photoshop does with some sort of interpolation? And if the graph goes back down to 512, does it go back to its original imported resolution or does it only consider the current resolution at one time, meaning it forgets what resolution it was imported in once the res changes.

Same question for SP?

Although come to think of it, I would think that spray pattern was probably made with an fx map rather than an imported bitmap? Not sure though since it's an sbsar so can't access the source.

We do bilinear filtering when upscaling/downscaling bitmaps