Brick Wall - Baking normal advice

OX14

So after reading several tutorials on how to sculpt brick walls and turn them into modular game assets, I am still having several issues baking the normal map.

I am trying to create a very simple brick wall. I have been following this tutorial:

http://www.brameulaers.com/tutorials/generic_wall_tutorial/generic_wall_tutorial.html

However I am trying to create a much simplified version of this, I am really just following the workflow.

I have several bricks with some extruded out and in more than others. When I come to bake the highpoly onto the lowpoly I get all sorts of artifacts down the sides of these extruded bricks. I believe the problem is in my unwrap of the low poly, I simply planar mapped the entire wall (following the tutorial) in order to get a nice flat unwrap. So obviously I am going to get these artifacts down the sides of the extruded bricks.

My question really then, is how do I go about creating a nice unwrap that will bake my normals nicely but also provide a nice unwrap to paint on when it comes to creating the diffuse?

Im at work at the moment so cant currently provide any screenshots, il update my post with images as soon as I get home though.

Ben Apuna

It sounds like you need to relax your UVs a bit.

You don't want the UVs of the sides of the extruded bricks to completely overlap each other.

The UVs on the sides of the bricks need some pixel space so that the normal/AO/etc... information can be baked onto the texture.

From the tutorial:

"After that I did a quick unwrap, just a flatten map and then relaxed, so I would get one continuous texture with no seams. Then baked ambient occlusion and normal maps to the texture. "

OX14

Thanks for your response Ben.

Yeah I did actually try something like this, I even went as far as to scale down the front polys so that they would get a bit of texture space once planar mapped.

Unlike the tutorial my low poly bricks are all separate elements rather than one continuous mesh, so when I try to relax it (using the standard max relax tool under edit uvw) they all relax far to much even after changing the default relax settings.

Ben Apuna

Any particular reason for going with separate elements?

Generally speaking it would probably be more efficient for a game engine (less verts) that is if this is for a game, and easier to unwrap as a single continuous mesh.

OX14

Cause im a lazy sod haha. I started by making a single brick from a box in max and sub-d it to make zbrush behave, sculpt in z brush, import the sculpt back into max over the top of the original box (remove the sub-d on the original box to form the low poly one). Then I simply instanced the the low poly and high poly sculpt to form individual bricks. Thats the reasoning behind the different elements.

But I will go back and create one continuous mesh from all the low poly elements and hopefully will unwrap allot better. Il let you know how I get on once I get home. Thanks for the help appreciate it.

OX14

A definite improvement from my first attempt, but still not what I am after. I will try to relax the extruded bricks uv's a bit more. Any other advice? render settings, cage settings etc etc?

I guess ultimately there is only so much you can do with a base mesh.

Ben Apuna

In this case because your wall is so uniform and flat, I think you would be better served by using a single quad as your low poly mesh.

Doing it that way though you'd need to adjust your high poly bricks so that the sides flare out a bit as they go further back into the wall. That way they will show up better in the baked normal map. You could probably accomplish that pretty easily by using a lattice/ffd deformer/modifier on each high poly brick without having to remodel them.

It also looks like you might want to adjust the positions of your bricks to take tiling into account. It looks as though all your bricks are supposed to be a uniform size, but on the sides where the texture/mesh will tile you will end up with some short and long bricks.

See these articles from the wiki about baking extruded shapes onto a normal map:

Sloped Extrusions



Modeling High/Low Poly Models for Next Gen Games

OX14

Yep you were right! Much cleaner results with just a single quad. Thanks I ended up using a FFD to flare out the bricks, and as they were all instances it didnt take very long at all.

Yeah it doesn't tile very well, and the bricks are far to extruded. Going to treat this wall as just an exercise for practising baking normals for sculpted objects. I think I will go back and redo the entire wall, make the bricks smaller/tile correctly and generally just make a more realistic brick wall.

Il post some screens when iv got some progress.

SpeCter

One suggestion: Try to use the Grid(and snap to it) it will make things easier for tilling.