I want to bake a normal map for very round sphere.

it is a very simply sense

1 create a sphere at /obj ,dive in ,set type ploygon mesh then uvflatten
2 copy that sphere at /obj ,dive in ,set rows and columns to 500,delete uvflatten

then create rop,and create baketexture node .


I got the Nt map. but it's a flat blue map . i don't know why . Could anyone give some advice ?

but if I add a mountain node for high division sphere. it bake correct.

After I import the nt normal map ,low sphere to UE4 ,of course create material and assign normal map ,but it's look like the the the low sphere in houdini . But I think it's should be a very round sphere. I guess the problem is the Nt map,because it is a flat blue map not a map with some tangent blue colur.


It's will be very nice if any one give any advice.

normal maps are not displacement maps.


Olaf

Olaf Finkbeiner
normal maps are not displacement maps.


Olaf

thank you for reply .
but after i bake ds map ,nt map, I create material and add to low poly sphere. it also the same .any idea ?

Hi. The reason why the tangent-space normals are flat is likely because the low-res sphere has smooth normals (the normals interpolated across its surface lines up with the normals on the hi-res sphere). If you use faceted normals on the low-res sphere (eg use “normal” SOP to assign per-vertex normals with 0 cusp angle) and bake Nt, you'll get what you're looking for.

dlee
Hi. The reason why the tangent-space normals are flat is likely because the low-res sphere has smooth normals (the normals interpolated across its surface lines up with the normals on the hi-res sphere). If you use faceted normals on the low-res sphere (eg use “normal” SOP to assign per-vertex normals with 0 cusp angle) and bake Nt, you'll get what you're looking for.

thank you for your reply .


I got the Nt map as you said . that's really a help.

but the problem still not be solved . i also cannot get the low poly sphere look like high ploy shpere .



1, i create the princip material .

2 ,in the bump& normal tab ,click enable,and add the Nt map texture just baked .then assign to the low ploy sphere. the sphere also look like nothing happen as below picture show.