Zylann
commented
6 years ago I wish Godot had togglable #ifdef support in its shader pipeline (https://github.com/godotengine/godot/issues/17303), because that would be one of maaany options I wish the terrain shader could have... I cannot switch shader just for regions of the terrain, and I also can't have much options either at the moment, because that would mean I have to add if blocks all over the place (bad!) or copy/paste the shader dozens of times (also bad). I already have two if for holes (which is legit) and depth blending (which is not), I would like the latter to go away as well...
Also, using triplanar sounds like an expensive operation to add to a shader that some people already have difficulty to run (https://github.com/Zylann/godot_heightmap_native_plugin/issues/22). The current shader has to sample at least 8 textures at once + a few others + the ones Godot inserts internally. 8 fetches are used for splat textures. Triplanar multiplies those by 3, which becomes at most 24 fetches, JUST for the splats.... that's quite a lot, and further reduces the amount of users able to use it. (the article even explains performance is the first downfall). That comes down to the technique being used of course, which I plan to migrate to texture arrays once Godot supports them, but I will still need 8 base fetches unfortunately... Perhaps it could be reduced by using triplanar only on some of the splat textures though. For example, that would raise from 8 to 12 instead. You see now I need ability to code shader options pretty badly before that^^
For now, I can eventually add an option that will enable triplanar mapping only on the FIRST splat texture, which means 1 more if block in the fragment shader to do 4 more texture fetches. So it can be done, but not as efficiently as I would like to. Ideally, I really would like to replace those ifs by #ifdefs because they will almost never change during the execution of a game.
Otherwise, your only go is to modify the shader and implement triplanar on the textures you want, which shouldn't be too difficult (if you know about shaders).
There is another alternative for cliffs that looks better, which is to use cliff meshes (regular models) instead of leaving a stretched heightmap, because, well heightmaps aren't good at cliffs anyways :)
DigitalMonkeyPa1
Tri-Planar mapping can eliminate these, but performance may be disturbed. https://gamedevelopment.tutsplus.com/articles/use-tri-planar-texture-mapping-for-better-terrain--gamedev-13821 This post explains how to use tri-planar mapping, but it is for jMonkey engine, but the shader code looks almost similar to godot's shader language. Putting an option to enable or disable this one would be cool.