Skip to main content

Problems with map display...

I spent a total of about 4 hours trying to find out why my map wasn't displaying properly.
Turns out there was nothing wrong with my code, or my shader, the problem was in the imprecision of the floating point numbers used to scale the UVs and the default use of sRGB color space by blender.


(top left) This is similar to what I was getting, obviously not right, but I couldn't figure out why.  
(top right) Using data from the map each square is given a red color from 0-255.
(bottom left) There are 16 possible arrangements of tile and the red color offsets the UVs of that tile by a set amount.
(bottom right) The rather unimpressive final base result.

When scaling UVs Blender avoids imprecision in floating point number by just rounding up to a more suitable number, so 0.0625 becomes 0.063. This is fine usually, as you don't really care about pixel perfect placement in most applications. But when your total image is only 32 pixels across it can cause issues as 1 divided by 16 is NOT 0.063! Easy to solve, I had to add a second modifier after the offset to correct the rounding. But I didn't even know about this problem until I had solved the second one...

Blender uses sRGB color space by default. This is fine as nearly every application does these days. But the above method relies on linear color distribution, each color must map exactly to its true value or the offset will be wrong. This was solved by switching color management for the offending texture to simple RGB color space. Sadly the setting for this is hidden away in a collapsed tab in the texture settings, so I only thought about it after a lot of time wasted modifying code and testing other solutions.

So finally, the map display works. However... I'm not sure I like the result. :(
It's great that I solved the problem though as I can use this method in Vinland 1936 for texturing the terrain.

Comments

Popular posts from this blog

Automating Level imports from Blender to Godot

  Recently I've been making some levels in Blender an importing them into Godot. There are only about 7 or 8 shaders for each level, not counting dynamic objects which will be added later. But to improve rendering performance, it can be a good idea to split the meshes up into sections. At that point you might be faced with a list like this: Or it might be even more chaotic, if you didn't use simple names for the objects in your level. So it can take a long time to sort out all the meshes, make them unique and add textures and so on. Blender imports with simple Blender textures, or with placeholder materials. This is sometimes OK, but if your Godot shaders are very different to those used by Blender, it means applying new materials to every mesh object in the level when you import the scene. I found that during the design process, I was importing and readying a level several times before I was happy with the final layout. So at first I was wasting a lot of time. In Blender, I us

Dynamic terrain in GODOT

Long time no posts. I haven't been keeping up with the projects I started. At first it seems fun and exciting, but I always run in to limitations in the setup, plus the grind of just making stuff without any real challenges... It ends up being something that I don't want to commit to. So right now I'm just messing around with some ideas and see what comes out. No commitment to a bigger project, just some time to try new things. This week I've been working on procedurally generated terrain.  In the past, there were some big limitations on how I approached this, because the game world had to have the whole map, from the micro to the macro. I had to choose a scale somewhere between, which meant I couldn't have really large maps, or really small details. I think I've found a way around that. Below you can see two types of map data coexisting on top of each other. The wireframe is the collision data, used for physics and for clicking on the map, to move characters ar

Make your game models POP with fake rim lighting.

I was watching one of my son's cartoons today and I noticed they models were using serious amounts of simulated rim lighting . Even though it wasn't a dark scene where you'd usually see such an effect, the result was actually quite effective. The white edge highlighting and ambient occluded creases give a kind of high contrast that is similar to, but different from traditional comic book ink work. I'll be honest, I don't know if there's a specific term for this effect in 3d design, since my major at university was in traditional art. I learned it as part of photography. You can find plenty of tutorials on "what is rim lighting" for photography. It basically means putting your main sources of light behind your subject so that they are lit around the edges. It can produce very arresting photographs, either with an obvious effect when used on a dark subject ... ..,or as part of a fully lit scene to add some subtle highlights. See ho