Decals trembling

[Marcousik]

I want to build a road with the decals, but then the road is trembling each time the camera moves:

 

I'm on terrain 4096*4096

Any idea why this occurs ?

 

[Marcousik]

Update: Tested on 512 map, no bug so occurs only on 4096 terrain, but can't tell why

Update 2: It seems it is trembling only at the begin and at the end of a camera move. While the camera is moving it is ok.

[Josh]

How far away are you from the center point? (0,0,0)

[Marcousik]

[Josh]

If it doesn't happen with decals that are close to the center of the scene, then I think this is just 32-bit  floating point precision in action.

[Marcousik]

3 minutes ago, Josh said:

I think this is just 32-bit  floating point precision in action.

Right it is not tembling in the middle of the map, ok.

But do you know how to fix this? Or that would mean for my game design no roads after range (x,y) ?

[Josh]

Use 64-bit floats:

www.ultraengine.com

[Marcousik]

One thing I don't understand if why does the trembing not appear in the preview editor?

[Josh]

Try turning real-time render on in the editor.

[Marcousik]

It does not appear, I tried, no problem, only ingame

And the bug appears even on 1024 map at the edge. 

[Marcousik]

Could it not be a shader bug

[Yue]

5 hours ago, Marcousik said:

One thing I don't understand if why does the trembing not appear in the preview editor?

I think it has to do with the Occlusion Culling system that is disabled in the editor.

[Marcousik]

Ok maybe? But is that not strange that everything goes ok at the edges of a map... except decals?

I mean shadows, models, cng, emitters all work fine ,but decals are trembling. I m bit disappointed, it would have built good roads effects.

[Genebris]

Have you tried lowering camera far clip / increasing near clip? Just in case this is due to depth buffer precision somehow.

[Marcousik]

6 hours ago, Genebris said:

Have you tried lowering camera far clip / increasing near clip? Just in case this is due to depth buffer precision somehow.

I don't know about that. Could you give me details, where/how? Function?

[Genebris]

https://www.leadwerks.com/learn?page=API-Reference_Object_Entity_Camera_SetRange

No idea what default numbers are, so use GetRange first

https://www.leadwerks.com/learn?page=API-Reference_Object_Entity_Camera_GetRange

[Josh]

Defaults are 0.1-1000

[Marcousik]

@Genebris Dude 1000 Thx that made it, set the range to 0.5-600 fixed the tremblng 

I will credits your name for saving this idea if my project ever get finished! 

[Yue]

NIce!!

[Marcousik]

How performant are decals? Did anyone have an idea how much of them a map will support (approximativly)

I hope decal isn't that heavy because it has no shadow, no physics, no shape.

[Yue]

 

This will largely depend on the hardware power of the computer, so it is then up to me to implement a menu of drawing distance options for these objects, and for the end user to change these parameters to optimize performance.

Decals have draw distance parameters

 

[Marcousik]

Ok thx

[Yue]

Something I was thinking is that decal textures trigger mipmaps that far away degrades the quality of the texture, all this helps the performance of the decal that when far away does not show in high quality.

[Marcousik]

Yeah everything depending on the PC configuration, but overall I did a quick performance test and the results are incredible good:

That means more than 1600 decals be rendered at max view setting, tracing 6 roads over a 4096 map by 55-60 FPS

Video Card GTX 1660 - 6Gb

[Genebris]

Did you have vsync enabled? Also it's possible that amount of them doesn't matter as much as coverage of pixels on the screen. Josh knows if it's true.