Bump area VERY narrow

Started by Dune, October 27, 2019, 03:26:33 am

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WAS

October 29, 2019, 08:07:52 pm #30 Last Edit: October 29, 2019, 08:19:07 pm by WAS
Quote from: Matt on October 29, 2019, 05:18:49 pm
Quote from: WAS on October 29, 2019, 05:00:31 pmBoth methods very clearly describe the same end results, not effecting geometry, by simulating the lighting via normals. Both results yield the same non-edited geometry (the sphere is still smooth as well as the casted shadow)

Yes.

Quote from: undefinedIn TG it's creating displacement, which is seen along the object, and in the shadows.

If you see the silhouette of the object change, this is displacement. In Terragen that will happen with displaceable objects. That was Hannes's sphere on the right. But Hannes's sphere on the left was just bump mapping.

Quote from: undefinedWhich results in weird looking objects it seems, especially with light interaction.

Yeah, that is the main problem with bump mapping.

Quote from: undefinedAt which point does this become displacement, and not simulated bumpiness of light? The height map method says it's used to get the normals, for the lighting. Not using it for actual physical displacement.

Correct, bump mapping just changes the normals for lighting. This is what Hannes's left sphere shows.


Hannes's sphere on the left very clearly has displacement... you can see in on the sides of the sphere and shadow, though. So I don't understand. This isn't "Bump" mapping, which is simulating bumpiness of lighting only.

Even in my ray traced example, it's very clearly creating displacement, very weirdly, I might add, over the same normal map simply converted to depth.

The way it is now, seems like it's own thing, trying to create displacement from a bump map, rather than lighting. For example, some materials of objects that use displacement and bump. You'd get strange results with the added displacement playing with light on top of the simulating lighting effect it should be doing, as the displacement is suppose to be the actual geometry/mesh adjustment, not the bump.

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When I zoom into the Normal Map version, it creates near back depression shadows where it should be fairly subtle, over the actual diffuse of the object (Fabric31). Is this because it's simulating lighting on top of creating displacement? Cause it looks bad.

Matt

October 29, 2019, 08:55:54 pm #31 Last Edit: October 29, 2019, 08:59:22 pm by Matt
Re. Screenshot_19.png:

Shadow on the ground: If the sphere is ray traced, any roughness you see in the shadow on the ground is caused by aliasing, not displacement, because there is no displacement on ray traced objects in Terragen 4.4. If we want to displace the shadow at all we need to use a displaceable object or the use the mesh displacement feature (deformation) on a high-poly model.

Silhouette: If the sphere is ray traced, any roughness you see on the silhouette is caused by aliasing, not displacement, because there is no displacement on ray traced objects in Terragen 4.4. However, if the render method is set to "force displacement" then it will displace the surface and the silhouette, but not the shadow.

Re. HardBlackShadowArtifacts.png:

This depends on the version of Terragen because its behaviour has changed a few times over the years. In some Terragen builds there may be some shadows appearing in the dips of the bump map on the surface of the object itself, and in the raises it can adjust the position of the terminator. This was an attempt to try to make it slightly better than traditional bump mapping. It was removed in v4.0 but added again in v4.1 because it can be used to work around certain terminator faceting issues. But it leads to other problems (including incorrect transparency) so it's been disabled again in build 4.4.40 frontier.
Just because milk is white doesn't mean that clouds are made of milk.

WAS

Again. Displacement is very clear, his, and mine... That's not just AA Matt. Ray tracing objects is applying displacement...

TG Frontier 4.4.40

And the shadow effect is too hard and fake and entirely changes material I'd say. A checkbox may be in order instead of arbitrarily adding/removing features at whims of complaints or what not. Seems more logical and easier to manage in the development path.

Dune


Matt

Quote from: WAS on October 30, 2019, 03:51:04 amAgain. Displacement is very clear, his, and mine... That's not just AA Matt. Ray tracing objects is applying displacement...

If you're talking about the cloth render then I will look into what's causing the black spots if you send us a TGD where this happens. But if you are talking about Hannes's sphere (the one on the left) then you are entitled to your opinion on whether it's doing displacement but I seem to have run out of ways to help you with that one.
Just because milk is white doesn't mean that clouds are made of milk.

Hannes

Although I initally didn't want to discuss this anymore, here is one last try.
Once again I used exactly the same settings for both images except the render method. The first one shows BUMP (Render method "Default"), the second one DISPLACEMENT (Render method "Force Displacement"). As you can see in the first image there's a perfectly round silhouette of the imported sphere, since it's only faking displacement. The second image shows a really displaced sphere.

Matt

Just because milk is white doesn't mean that clouds are made of milk.