Jagged Shadows & Edges with Normal Map

PineCliff

I have been rendering a model that I am working on using Iray and I have found an issue that I can´t seem to solve.

When I add a normal map to the model I get ugly square shadows and in various places the model edges show through making the faces look square. I have included 3 picture, 1st without the normal map (which looks fine), 2nd with the normal map applied and 3rd with studio lighting from a set I bought. I made the normal map from my texture using a free browser service and renders have all been done using the default render quality.

I have tried subD which looks a little better however there are still square looking faces (albeit smaller).

I have checked the model itself and it looks smooth in Hexagon, plus MeshLab doesn´t throw up any duplicate face problems.

I have also tried tinkering with all the sliders on the materials panel (I am using uber as my base).

Any help will be appreciated :)

felis

Are you sure that those lines are along the mesh edges?

Normal maps should not follow the mesh, as it is just a lightning illusion.

And have you only applied the normal map between the first 2 pictures? And if you lower the strength og the normal map, does the lines then dissappear?

If that is the case, then it must be the normal map itself. How have you made that?

PineCliff

felis said:

Are you sure that those lines are along the mesh edges?

Normal maps should not follow the mesh, as it is just a lightning illusion.

And have you only applied the normal map between the first 2 pictures? And if you lower the strength og the normal map, does the lines then dissappear?

If that is the case, then it must be the normal map itself. How have you made that?

The first picture is without normal map, it's perfectly fine. The second two are with normal map added. I made the normal map by uploading the texture to a free site that then generates normal and bump maps for you. I am a little stumped. The model also looks smooth and fine in Hexagon. I made the UV map in Silo the models always look a little blocky there.

felis

Just to test. Could you find another normal map and apply that?

Many shaders has a normal map, so just try to copy one from such in instead and see how that looks.

PineCliff

felis said:

Just to test. Could you find another normal map and apply that?

Many shaders has a normal map, so just try to copy one from such in instead and see how that looks.

I tried normal maps from two different fabric packs and the problem is still there without any variation from using my normal map. It is very strange.

felis

New suggestion.

Try to apply the whole shader, you tried to use the normal map from, to the modelm and see how that looks.

Or try to make a screenshot of your surface settings - it sounds as if something is wrong.

Szark

could also be down to what the normal maps have been saved as, SRGB8 (8bit) jpgs can result in this issue. 16 bit PNG will be better but since I don't mess around with human figures I can't say for sure. There is a plug-in for Gimp that can convert RGB maps to normal maps or the latest Photoshop CC2019 has a normal map maker biult in under Filters > 3D

PineCliff

felis said:

New suggestion.

Try to apply the whole shader, you tried to use the normal map from, to the modelm and see how that looks.

Or try to make a screenshot of your surface settings - it sounds as if something is wrong.

Applying the whole shader didn't make any difference. However I have solved the problem by adding a SubD and then raising the Render Subdivision to 3. Its odd but I'm guessing that it's a render thing.

Thanks for the help felis and Szark. Im going to look into that Gimp plugin too.

PineCliff

Szark said:

could also be down to what the normal maps have been saved as, SRGB8 (8bit) jpgs can result in this issue. 16 bit PNG will be better but since I don't mess around with human figures I can't say for sure. There is a plug-in for Gimp that can convert RGB maps to normal maps or the latest Photoshop CC2019 has a normal map maker biult in under Filters > 3D

The new Normal Map made with the GIMP plugin looks great in render without any SubD.

Thanks for that Szark.

Szark

my pleasure I should have added that I normally use the Sobel 3x3 preset