Game maker 3d projection

Note that this can have unwanted results when scaling each axis non-uniformly, as the scaling happens after rotation, unlike when drawing sprites which scales and then rotates. To work around this, you must build at least 2 matrices and multiply them or use the new matrix stack. Anyway, onto building the matrix. For this example, I will use a matrix to move the drawing to the center of the room, and rotate it by 45 degrees about the Z-axis.

We must then assign this matrix to the world matrix. This is best done in the draw event, right before you need it. After drawing your transformed output, you should reset the transform matrix to the identity, so drawing returns to normal. And that concludes the basics of transforming in 3D. This is used like this:. It seems to be a handy way of sotring matrices globally without the use of vars. It is important to remember that this does NOT affect the drawing of transparent textures!

Draw-order still matters too! Note that depending on how you build your projection matrix, you may need to reverse the cull order. They are far more flexible now. So you no longer have a choice between automatic flat or gouraud shading — the alternative is to write a shader and make sure your normals are correct for the type of shading you want.

Luckily, my Blender export handles both flat and smooth normals on export. Noting the above cameras, we used negative fov and aspect values in order to use left-handed space. Layer depth — this is a thing that can and will affect any 3D rendering! Layer depth of the instance that is drawing is added on relative to the current world matrix! Keep this in mind if something seems to have its Z offset weirdly.

Vertex batches — the more of these, the slower your game can run as more info has to be sent to the graphics pipeline. This is more of a concern on mobile targets as most modern PCs can handle a lot, but optimisation is still important and good. When using normal rendering e. In my experience, the limit is much harsher on mobile platforms in general.

This is not a complete explanation or list of solutions, so there may be better ways out there, but this should at least help point you in the right direction and help you to understand what is going on here. Often, you want to draw something transparent. You expect to be able to see anything behind it with no trouble at all. After all, it works just like this with all the 2D games you made, why would this be any different in 3D? When working in 2D with the built-in functions, depth and layers, GameMaker manages draw order so you never experience this artifact of rendering transparent things.

As soon as you switch to 3D, enabling a depth buffer and start rendering in ways GameMaker cannot automatically manage, suddenly this problem rears its ugly head. When something is rendered and z-writes and z-tests are enabled, the process is a little more like this:. No information about transparency is stored, therefore, anything drawn behind but after a transparent shape is discarded, so it appears invisible, however, things drawn before the transparent shape appears as expected.

Some of the process of the tests can be tweaked e. This has the benefit of beings the fastest and easiest solution, but comes at the cost of disabling transparent rendering often completely. Well, unless you do a little more work. More on that soon. The problem is that it can make things get way too bright, due to the additive blending, and can make the order of things look very..

Note that we still leave z-testing active even though z-writes are disabled, so that particles do not render on top of things that they are behind. One of the simplest ways to be able to render transparent things without too many artifacts is to use z-ordering when rendering. In some cases, you may have a mesh that has both transparent and solid parts.

You may want to split this into multiple meshes, but this can cause performance hits. You kinda have to go by trial-and-error to see what gives a good balance of good visuals and good performance.

These will require sorting by the distance to the camera. In some cases, you may still find it useful to disable z-writes and use additive blending to make self-overlapping transparent meshes render with fewer artifacts.

You have to decide if this is worthwhile for your game on your own though — if you have a complicated fragment shader and the GPU is a bottleneck, sorting beforehand may be beneficial. You can actually just use one group and order everything , but this can have more of a hit on performance and still leave artifacts when transparent and non-transparent meshes are at similar depths. A method that solves most of the problems, at the cost of performance, is Order-Independent Transparency.

This is a really cool method that allows you to draw in any order and still have transparent things appear properly, even at close proximity and even within a single mesh.

It would be easier if there were more hardware support, which I believe the Sega Dreamcast had…. Okay, I think that covers the basics!

I will be adding to this, especially when shaders are public. If you have any questions or corrections, let me know! Hey there. Thanks for taking the time to make this. Thanks again! Any tilemaps in your room should be visible in 3D space — the main thing to keep in mind is that the Z coordinate of a tile will be the same as the depth of the tile layer the tile exists on.

Haha, no problem! Your email address will not be published. Save my name, email, and website in this browser for the next time I comment. This site uses Akismet to reduce spam. Learn how your comment data is processed. M McFab mMcFab administrator. M McFab administrator. This guide is written with beginners to 3D in mind. A lot of matrices are autogenerated and assigned in the code without ever needing to know how they work.

However, knowing how they work can help a lot. X, is NOT a 3D engine. You will need to know how to use GML. This guide is written with beginners of 3D in mind anyway. X draw GUI , and there are already guides and help available. Remember to use the manual! It answers a LOT of the questions you may have, and can give you more information about a function. Tutorial : 1 Setting up 3D requirements and a 3D projection with the new camera To begin with, the following code will all go in the create event of some kind of control object, unless I specify otherwise.

Okay, before we even get started, we need to enable some things. This updates were the camera is looking from, without having to unnecessarily update the projection.

The winding order has been maintained so drawing is consistent if culling is enabled. Hence, the batch is broken. This is pretty challenging for a couple of reasons. Sprites are on texture pages. That really sucks. In that case, you can safely pass in -1 as the texture.

A vertex format determines how the vertex buffer is built and interpreted by the renderer. It needs position and color data at minimum, but texcoords are required if you want to display textures over geometry. Vertex formats can be defined at any time before you start to build the vertex buffer, so I put mine in the create event of a controller object. This is the fun part! We need to iterate over a grid once to build each cell of our grid into world geometry. This is where we build the actual geometry.

For each cell, we need to build up to six walls, so we loop through the size of our wall enum and send that value in. If you compare it with the other wall building code in the sample project, you may notice some patterns. If you do not conform to these patterns when building geometry, you will get culling and texture errors on render. The order triangles are built in does not matter, but the order their vertices are built in does.

As an alternative to manually defining all six walls, it is also possible to build two triangles six times and rotate each pair, but that is outside the scope of this tutorial. You need all three of these functions to properly build in the provided format. Texcoords are another type of coordinate system, this time normalised 0 through 1.

A texcoord can be understood as the coordinate pair on a texture where a particular image starts or stops. You can use these to perfectly align textures or stretch and squash them. Using the example texture for this tutorial, you can see these coordinates are y-down. Coincidentally, GameMaker is also y-down. If we place four images on our sprite for use as our texture, then we need to remember where each image begins.

These coordinates are inserted into the vertex buffer after our position data, but for the sake of clarity, I have removed all other vertex functions from this example. Before we can render anything on screen, we need to tell the renderer how to approach the scene. Because only a very simple camera is necessary, I will be providing some code as-is and very briefly explaining what values are for what.

If you would like to learn more about projection matrices view the resources at the bottom of this tutorial. In GameMaker, the render matrix variables view, projection and world directly affect the application surface — no need for messy camera or view setups!

Because we are rendering a Z-up world in this example, the third set of arguments, Up , is [0,0,1]. It is also common to have a Y-up world, using [0,1,0] instead. If the view matrix is the camera property representing its position , then the projection matrix is the camera property representing its lens.