Problem with the sobel edge detection [UDK]

Ganon

Hi guys ! I'm not a technical guy ...

I take the sobel edge detection from the forum of UDK . It's working quite good but, i've a problem with distant objects.

Look on picture:

Without skydome :

With Skydome :

There is a special parameter in the material effect ?

If someone want a screenshot of anything, tell me ...


Thank is advance

JamesWild

Unfortunately that's pretty unavoidable, and is one of the main problems with Sorbel. The depth buffer is nonlinear and loses a lot of accuracy at a distance.

While you could disable the outlines past a given depth value, that would prevent near objects making outlines on the skydome.

If you make the skydome translucent and give it an alpha of 1.0f, it will appear solid but not write to the depth buffer, so the Sorbel will ignore it. But this has other problems (sorting and stuff) and is not an ideal solution.

Farfarer

Is it not possible to set the skydome shader to not write to the Z-Buffer?

Ashaman73

I'm not using UDK, but outlines in my game. A good idea is to fade them out at a certain distance, this has the benefit of removing outlines for small objects in the distance too, which is very annoying sometimes.

The depth buffer is nonlinear and loses a lot of accuracy at a distance.

Disclaimer: I don't know UDK.
The z-buffer is often nonlinear, but in deferred render pipelines the depth buffer is often linear (faster and better position reconstruction).

JamesWild

Farfarer wrote: »

Is it not possible to set the skydome shader to not write to the Z-Buffer?

Sadly I think using a blend mode is the only way.

Ganon

Thank for the reply ! I put the material in "translucent mode" and it's working good !



thank you very much !

spectre1130

I saw this in the P&P forum and it is nothing short of awesome. I commend you for even trying such a complex shader. I wouldn't touch that with a ten foot pole at this point. Good job!

Oniram

scale the skydome really big

Ganon

@ spectre1130 : Omg, thx you )
@ Oniram : it's just a test with a skydome from UDK, not mine . I don't really know the "good" scale for a skydome