Displacement issues

[james_g_brown]

Hi,

On various external images we have been creating lately we have been using displacement for bricks and have experimented with numerous settings but always run in to some trouble.

If you look at the attached image you will see that in the render on the left, the brick isn't 'sharp' and the edges all look a bit crumbled and are not nice and sharp, even though the b&w map we are using (top right of the image is nice and neat and sharp.

Has anyone else had this issue? Its the only thing in Corona that is holding us back at the moment and if we can rectify this we will be super happy!

Any help would be great.

Cheers,

James

[James]

You could lower the screen size in Displacement under Performance in the render settings.

[james_g_brown]

Hi. Yeah we have tried that. It helped a little but when we have brick taking up such a large part of a 5k image it didn't really do much and would often crash our scene if we lowered it too much.

Thanks

[James]

What res are the brick maps?

[james_g_brown]

8k

[James]

Even though 8k is big, its divided up by alot of bricks. Looks like 24 bricks wide, so thats only 333px per brick - which when you look at it that way, its not very high res for those fine joint lines.

Also have you got them as Coronbitmaps or normal bitmaps? The different filtering opts shown here might help you out.  https://coronarenderer.freshdesk.com/support/solutions/articles/12000033420-what-is-the-difference-between-corona-bitmap-and-3ds-max-bitmap-node-

[james_g_brown]

We have tried using max's 'tiles' for displacement as well to get rid of any maps and texture sizes and still had the same results.

thanks for the info about filtering. We will have a play with those and see if it helps.

Cheers.

[maru]

Try blurring the displacement texture a bit. It may sound counter-intuitive, but it will be actually easier for Corona to render without edge artifacts, and with low blurring, the edges should still stay quite sharp.

[james_g_brown]

Thanks Maru, will give that a try as well.

[romullus]

That should be quite easy to test. Move your camera closer to the brick wall and render small crop. If bricks still looks bad and jaggy, then it's probably due to low quality/resolution of displacement texture. However if it looks much better at close up, then most likely that means that displacement screen size is too big. If i'd have to guess, i would say it's latter. In your attached example, gaps between the bricks are about 2-4 px size, that means at default settings they are subdivided just in 1-2 triangles - that's nowhere near enough for good looking displacement.

I would probably leave displacement for close-up shots and for distant ones i would use normal map. The gaps would look much cleaner.