So I figured it out kinda. I created empty project and editing .c3proj file was enough. I added just one sprite afterwards and the error happened again. So I edited "sprite.json" file in "objectTypes" folder and changed "exportFormat" property from "losless" to "png" and it solved my issue.

dop2000 I see the following error in the console:

[Project] Exception opening: Error: invalid export format

at p.pwa (projectResources.js:187:50)

at p.La (projectResources.js:201:138)

at p.rma (projectResources.js:202:145)

at g.oxd (projectResources.js:179:205)

at e.qma (projectResources.js:164:373)

at p.txd (projectResources.js:135:239)

at async Promise.all (/r251-2/index 8)

at async e.Qhc (projectResources.js:139:120)

at async Fa.Zhc (projectResources.js:1089:385)

at async window.xib.C_ (main.js:2105:47)

lOa main.js:2108

C_ main.js:2105

await in C_ (async)

jP main.js:2097

await in jP (async)

(anonymous) main.js:2064

So it seems that it has something to do with the format of some project files. But all images are in .png and all audio files are in .webm format. Can you give me any advice please?

Hello!

I have a non-trivial question. Due to the specifics of my job I have to work with the older versions of C3 like r251.2 or r241 and sometimes I need to open projects created on the newer versions of Construct on the older ones. Usually I just needed to edit "savedWithRelease" property in .c3proj file, disable 3d rendering and/or enable orthographic projection to make project comaptible.

Everything worked fine until the recent updates. Now when I try to open the modified project file (that was previously saved on the newest versions of C3 like r308) I get the following error all the time: "Failed to open project. Check it is a valid Construct 3 single-file (.c3p) project."

I can't even copy any object (e.g. sprite, particles) from one project (opened in r302+) to another (opened in any older version of C3). I get the following error: "Some items were not pasted. Not all the copied items could be pasted to this project. Check all the names and requirements match."

However if I try to copy a sprite from the project opened in the new version of C3 and then paste its info from buffer into a text file and change the "exportFormat" property from "lossless" to "png" I'm able to paste this edited data into a project opened in the older version of the engine without any problem.

So at least I'm able to copy objects between the projects now. But what can I do to make the whole project compatible with the older versions of C3 again?

Any help is really appreciated. Thanks in advance!

Thanks Ashley! I can't believe that I haven't noticed this myself 😅

1drv.ms/u/s!AkmrWgxeuxlKhIg-7JoGEwomBLceSg

Play around with that.

That's an interest approach. Thanks for sharing! But I've achieved the desired effect using tiled background object with random X offset already.

change your display settings from Nearest to Biliniar or Triliniar it works for me. it is a rendering low quality issue.

Click project folder name in right side ... and left side on settings bar u have display area and under Sampling select Triliniar and is all looking smooth for me.

Yes, I know that. I meant that you can't use one long sprite because you'll have to stretch it eventually. And stretching will distort the sprite. And spawning tons of little sprites instead of particles will ruin the performance during an intense gunfight. That's why I switched to tiled background and achieved the desired effect with the random X offset property.

The events you have now should work with a sprite, it will face the same way as the laser.

One long sprite won't work because lasers can be of any length. It will look distorted and I need pixel-perfect image. On the other hand tiled background might do the job... I'll try it out today.

Looks like particles are better for spray in a direction, it doesn't rotate the original image. Better to use sprites as you mentioned above.

Spawning sprites along vertical or horizontal line is an easy task but what is the best way to spawn them alongside diagonal laser?

Rotating the particle object should help because it's the angle of the particle object that you need to change for the direction. When you spawn it, set the angle also with an action.

No, it's not working as I said before. Here is the sample .c3p file that demonstrates my problem. Shoot with LMB and you'll see that only horizontal shots looks fine.

dropbox.com/s/f25m5k73cxhry1q/laser_trail.c3p

Yes, you're right. Normal angle is what I was looking for. Now I just need to choose the best implementation for my game. Thanks for pointing me in the right direction!