I am looking for approach for casting hex based grid on terrain which is for now pre-made but eventually it will be procedural for my exploration game where you can scan planet and elements will be highlighted/hex grid selected. What could be the approach towards making this kind of hex grid as my terrain will be un-even.
I have seen approaches like mesh creation, using tile-map, unity projectors but eventually I feel like this should be something using shaders but what about selection?
Can someone please guide me in a right direction.
I think this topic is more like for https://gamedev.stackexchange.com .
My tips for you:
I think the hexa grid projection can be solved with Unity built in Projector, you can use ortoghraphic projection with it, so it does not matter if your terrain is uneven, also it has a convenient way for selecting which layers are affected only (terrain, your buildings etc...)
(The projector, is a shader magic tho, it blends the picture you give it to it, and the layer below it)
If projector does not satisfies your needs, im pretty sure there are grid shader already written for unity.
About the selection, i think you could also solve that with projector, or give some trail effect to the grid boundaries? - i guess you gonna still store the boundaries so..
About country borders in Civ:
I think they cast a spline using the hex grid border points, then blend it on the terrain. I saw a shader that could draw lines on a terrain, so you might found it!
Keywords for search: Beziér, Catmull–Rom, Spline, terrain shader
Related
I have a set of 2D polygon shapes, each one with a varying amount of points that are determined at runtime.
I need to draw (or "paint") these polygons on top of a surface.
I also need to fill in the areas of each polygon with a specific color that is also determined at runtime.
The polygons only really need to be drawn once, however solutions that would allow me to update/change the colors would be nice.The project will be built for WebGL.
The polygons are to mark of specific areas on a surface so they shouldn't repeat.
Polygons can overlap with eachother
What are the different/best solutions that may help me achieve this?
Am also open to suggestions and further reading
I'm a relative Beginner to Unity but a somewhat experienced programmer and know a slight bit about shader programming.
By polygons I don't mean geometry I just mean a regular shapes I would like to paint on to a surface. Its just that I will always have polygons with a varying amount of points that are loaded in at runtime.
First, u need to split the surface into that polygon then u need to have materials on them and the code that specifies the colour should update the colour of the material which is on that specific polygon. Creating materials could be done in code to avoid a lot of work in a simple loop.
I am pretty new to shaders in unity and am stuck on a problem.
I am using ShaderGraph and unity 2021. I understood the ShaderGraph examples from the unity page and "implemented" an OutlineShader thinking I could simply "inverse" the direction (not multiply by some value to get a bigger object then coloring that object and laying the original object ontop). Yet I am nowhere near what I want.
Basically what I am trying to achive is a stepped color gradient to the inside of the object. As an image it should look something like this:
Starting from color0 (green) going inward to color1 (yellow) until i reach the center with colorN (white) and repeat the same for the other side. The shader is then used on a material that is applied to a MeshLineRenderer (LineRendererPro from asset store with minor modifications for custom behavior) which kind of looks like this:
In the end the line should be colored according to the specified colors and the direction the line is going.
Explanation of a simple "Inline" Shader (similar to an outline) would help alot. I think I would be able to adapt that concept and implement multiple colors with (maybe) percentages of width. I don't want to use a fixed image/texture since i want to change the widths and colors.
Any input is welcome and thank you in advance.
I am beating my head a little bit here for a while but I still could bot find a way to set up a matrix that projects my Unity game in a Tibianeske like manner:
Reading on tutorials on internet I could figure out how a normal orthographic perspective works, but tibia's one is kind of odd.
Digging over webs I found in here a guy (Clint Bellanger) who describes really well how to get the same perspective in blender's render according to him:
Start with a scene in 45 degree isometric. Video game style, where
the camera angle is Blender (60,0,45).
In Blender if you look at Buttons Window -> Scene -> Render Buttons ->
Format, you can set the render aspect ratio. Set AspY to half of
AspX. This is the same as taking regular rendered output and scaling
X by 50%. If you rendered a cube, the top of the cube will be a
perfect square (though at a 45 degree angle).
We can then use Blender nodes to rotate the result 45 degrees. The
output:
Note this started as a cube, so there's a lot of "vertical"
distortion. So you might have to scale meshes to 50% Z before using
this method. Also notice the Edge seems to be applied after the
Aspect, so the edge isn't distorted.
Blend file: http://clintbellanger.net/images/temp/UltimaVII.blend (I'm
a Nodes noob so there might be a smarter setup).
For kicks, here is that tower again. I pulled it into the above
workflow scene and scaled Z by 50%. Click "Re-render this layer" on
the first node to create the composite.
On his method, he used stuff like rescaling the render and changing the scale of models, Im convinced I could get along just with the 4x4matrix in unity(or in any other 3d environment really).
Hope someone more experienced with perks of 3D maths could help me to figure it out. Thank you! =D
What you ask for is a simple parallel projection. The typical orthographic projection is just a special case where the projection rays are perpendicular to the image plane. However, every parallel projection can be represented by an affine shear transformation followed by a standard orthogonal projection.
Im convinced I could get along just with the 4x4matrix in unity(or in any other 3d environment really).
Yes. Using default GL conventions here, all you have to do is to take the standard ortho matrix, post-multiply it by an appropriate shear matrix and use that as the projection matrix.
As I understand it, the standard projection model places an imaginary grid in front of the camera, and for each triangle in the scene, determines which 3 pixels its 3 corners project onto. The color is determined for each of these points, and the fragment shader fills in the rest using interpolation.
My question is this: is it possible to gain control over this projection model? For example, create my own custom distorted uv-grid? Or even just supply my own algorithm:
xyPixelPos_for_Vector3( Vector3 v ) {...}
I'm working in Unity3D, so I think that limits me to cG or openGL.
I did once write a GLES2 shader, but I don't remember ever performing any kind of "ray hits quad" type test to resolve the pixel position of a particular 3D point in space.
I'm going to assume that you want to render 3d images based upon 3d primitives that are defined by vertices. This is not the only way to render images with OpenGL but it is the most common. The technique that you describe sounds much more like Ray-Tracing.
How OpenGL Typically Works:
I wouldn't say that OpenGL creates an imaginary grid. Instead, what it does is take the positions of each of your vertices, and converts them into a different space using linear algebra (Matrices).
If you want to start playing around with this, it would be best to do some reading on Matrices, to understand what the graphics card is doing.
You can easily start warping the positions of Vertices by making a vertex shader. However, there is some setup involved. See the Lighthouse tutorials (http://www.lighthouse3d.com/tutorials/glsl-tutorial/hello-world-in-glsl/) to get started with that! You will also want to read their tutorials on lighting (http://www.lighthouse3d.com/tutorials/glsl-tutorial/lighting/), to create a fully functioning vertex shader which includes a lighting model.
Thankfully, once the shader is set up, you can distort your entire scene to your hearts content. Just remember to do your distortions in the right 'space'. World coordinates are much different than eye coordinates!
Say the user taps 4 spots on the iphone, defining an irregular 4 sided polygon (in 2d space). Is there a way to map/fit a (potentially highly distorted) image onto this shape, without using OpenGL?
Something like:
Is my only option to somehow calculate the 3d space that my irregular 4 sided shape sits in (based on where the tapped 2d points sit), create an OpenGL plane in that space, and map my texture to it flatly? Seems like there should be an easier way...
Thanks in advance.
Update: After diving into OpenGL I'm almost there... but I still can't get the texture to distort correctly. The triangulation seems to be messing with the texture mapping:
I can't answer your question completely, but one thing I would say is that you don't need to think about any conversion / mapping to 3D. Using OpenGL you can easily draw the shape in 2D and have the texture mapped as you desire. No need for any fancy maths or conversions. It's no more complicated than drawing a rectangle. OpenGL doesn't care that your 4-sided shape isn't actually rectangular.