Dear NVIDIA Community.
Isaac Sim 4.1.0
I have encountered a bug while designing an MDL material.
From official NVIDIA MDL handbook:
https://mdlhandbook.com/mdl_handbook/index.html#displace#displacement-mapping-moving-a-surface-point
I took a waves_as_displacement material from Listing 12.5
My mdl code as copy from handbook:
mdl 1.8;
import ::base::*;
import ::df::*;
import ::anno::*;
import ::state::*;
import ::math::*;
import ::tex::*;
import ::scene::*;
float fit(
float v,
float old_min, float old_max,
float new_min, float new_max)
{
float scale = (v - old_min) / (old_max - old_min);
return new_min + scale * (new_max - new_min);
}
float sinusoid(
float f,
float frequency = 1.0,
float minval = -1.0,
float maxval = 1.0)
{
float fraction = math::frac(f);
float angle = fraction * 2.0 * math::PI;
float scaled = angle * frequency;
float sine_value = math::sin(scaled);
float result = fit(sine_value, -1.0, 1.0, minval, maxval);
return result;
}
float uv_wave(float2 frequency = float2(1.0), float2 minval = float2(-1.0), float2 maxval = float2(1.0))
{
float3 p = state::texture_coordinate(0);
float u_component = sinusoid(p[0], frequency[0], minval[0], maxval[0]);
float v_component = sinusoid(p[1], frequency[1], minval[1], maxval[1]);
return u_component + v_component;
}
export material waves_as_grayscale (
uniform float2 frequency = float2(1.0),
uniform float2 gray_max = float2(0.5)
) = let {
color tint = color(uv_wave(frequency, float2(0.0), gray_max));
} in material (
surface: material_surface (
scattering: df::diffuse_reflection_bsdf(tint: tint)
)
);
export material waves_as_displacement (
uniform float2 frequency = float2(1.0),
uniform float2 distance = float2(0.1),
color tint = color(0.7)
) = let {
float displacement_distance = uv_wave(frequency, -distance, distance);
float3 displaced_normal = state::normal() * displacement_distance;
} in material (
surface: material_surface (
scattering: df::diffuse_reflection_bsdf(tint: tint)),
geometry: material_geometry(
displacement: displaced_normal)
);
Material waves_as_grayscale shows perfectly using both RTX - Real-Time and RTX- Interactive (Path Tracing)
However waves_as_displacement does not work at all in any settings
@pcallender
MDL Displacement is not supported in Isaac Sim renderer or this is a bug?