Rojo3d. 3D engine for Construct 2

R0J0hound

Hi, maybe you cold give me a technical advice?

My game is moving forward every day, with the method "two steps forward, one step back".

I'm at the point where I have thought trough stopping using standard sprites (with roughly 12 collision mask points) and instead focus solely on 3D objects with assumption that it will release some of the cpu.

So far I've been using sprites as a collision detector as well as reference for 3d mesh.

With collisions the event started like this:

- for each actor, actor overlapping terrain, for each terrain.

but since I want to make sprites redundant I am thinking of putting all terrain data in to arrays. So first all level data will be in an array, roughly 2k objects with their data per level, or roughly 200 objects per room in a level. These are terrain object and each of them is a cell contenting Json data with npc's and other things that I load temp array with and place on the map. Checking if their are active can be done trough var change in an array. but I'm also considering having another array just with id's and distance to npc, so that I can sort it quickly according to distance and stop loop if distance is greater then a value.

Here are my doubts come in:

- if I sort array with 100 entries (if I use active objects array) or 2k entries ( if I do all checks inside map array), then check distance up to a certain distance and then pick those objects and do my collision code ( which is ellipse radius calculation done twice, once on xy plane and another on plane created by calculated radius and z to calculate z to place object on. Also first radius calculation is used as collision with walls if player is below floor range). Will that work as good or better then using LOS plugin to check x'y in one of the arrays, or work as good or better then checking overlapping with sprite? And how would that work if I had 40 npcs needing to check their surrounding to see if they are colliding with anything?

Also, the checks are spread across several ticks with counter, so if counter is 1 I do this and that, and then counter = 2 and so on. Obviously that is necessary.

Also, if id go with that, which 3D object position property would be mirroring of a sprite. Would that be XX, YX, ZX or XX, XY, XZ? I don't understand why there is so many variants for position in 3D, please explain.

Best

M

I aim for simple and easy to read with my events if I can. Using arrays to store object info instead of sprites may or may not be better, it just depends on how you want to implement it.

You can sort arrays, but you can also sort sprites with “for each ordered”, just use the stop loop action when loopindex=0 if you just want the closest. Or use a higher number to do stuff with more.

The only time I use an array for terrain is if it’s in a grid formation, in which case a tilemap can work too for 2d. If the terrain is different sizes and whatnot I’d just use sprites.

Not sure I grasp your distance calculation. Would a 3D distance calc work better?

Sqrt((x1-x2)^2+(y1-y2)^2+(z1-z2)^2)

I have no technical expertise with the fov behavior. I find behaviors seldom do what I want so I’m more inclined to do stuff from scratch than do things to bend behaviors to my will.

For your last question I think there’s a misunderstanding.

You get the position of objects with the x,y and z expressions as I recall.

The orientXX/Xy...Zz expressions is the orientation matrix of the 3D object. Aka. How it’s rotated.

You can think of those as three vectors.

OrientXX/Y/Z is the left vector of an object

OrientYX/y/z is the up vector of an object

OrientZx/y/z is the forward vector of an object.

That’s called “broad phase” collision detection. Basically doing approximate collision detections by using a distance check or something. Other ways are using bounding boxes, bsp, quad tree, collision cells, etc. construct already does it somewhat with the overlapping condition.

Anyways you can do that with events but you’d have to actually do it and test if it improves performance. The overhead of implementing those things with events can often result in things being slower oddly enough.

Anyways the logic of the distance check you describe could be:

For each sprite

For each terrain

Compare distance between sprite and terrain <100

Sprite overlaps terrain.

But with events you already reduce the terrain loop by doing this instead:

For each sprite

Sprite overlaps terrain

For each terrain.

But that’s mainly because internally construct can filter the objects faster than you can do manually with events which are slower.

You other idea of adding and removing objects as needed is another idea. But you’ll have to test it. This plugin was made so you only have to make events to update objects you want to move. All the static objects will just redraw fairly efficiently. Adding/loading on the fly would be slower but it may end up being faster in the long run. But you’d have to actually test it out.

R0J0hound Question re MeshTag:

I don't suppose there is mesh IID or UID, isn't it?

Would be cool to be able to set up all meshes of same group with single action without loops. Ie: MeshTag: cube, MeshId = 0 - pick all else pick nth.

You probably could get better performance by reducing the number of instances of the plugin. But I guess it depends on what you’re doing.

With the tags it’s just one per mesh. I was considering adding a group feature but I don’t have enough to time to implement it and test it without breaking things.

When creating 3D objects you can copy another object so you don’t have to set up each attribute. But other than that there’s no way to change a bunch of objects at once without a loop.

Hello R0j0hound!

An impressive job, no doubt. And I'm probably doing it wrong (after all, I've only been working with the plugin for a few hours), but still, I have some doubts.

First of all, 3D models do not appear anti-aliased. I wonder if I am doing something wrong (probably) or vice versa, this is how the plugin works.

And how do I load the textures? The only thing I've managed to do is load them through a sprite, but it doesn't affect the model.

In any case, thank you soooo much for the plugion and for not forgetting the C2 users!

Hi,

There is no anti-aliasing done.

To use a texture on a model there are two steps

1. Load the texture from a file or sprite to a tag. The tag is to refer to it later.

2. Tell an object to use a particular loaded texture. Should be an action under 3D appearance or something.

Thanks! I will check it ASAP!

Thanks! I will check it ASAP!

You can use image shaders to trick AA or just render in higher resolution with high quality up scaling and downscaling.

I had a little fun with Rojo3d and I'm impressed. I will definitely do something in my spare time, maybe some kind of ps1 demake horror.

I have not tested this idea yet but for example: rigged obj are not suported but I can swap obj frame seq files and sync them to the animated sprite frame for easier control?

like: if sprite(walk animation) is frame 1 then show walk_frame1.obj ...

Hi,

Yes can do that and swap the meshes used on the fly no problem. I imagine it would work well for stop motion.

Glad you’ve found it useful. I’m not currently developing it further. I coded myself into a corner and would need to take time to figure out the best way to rewrite it and I don’t have the same momentum or time to do that at this time.