[j_petrucci]

Hi,
I'm trying to use MXI images to simulate skylight like HDR; I used Maxwell Viewer to convert HDR to MXI then I create a big emitting sphere surrounding the scene then applied the MXI.

Unfortunately, HDRI lightning needs normals to be inverted towards the objects and the sfere is a closed NURBS surface which normals can't be inverted; so I created an hemisphere, but the texture went wrong because it also contains the ground that wasn't supposed to be at the horizon level...

But I don't surrender! I revolved an arc for 359° to make an "almost" complete sphere, with invertible normals! But here it comes the bigger problem: the only projection method Rhino plugin knows to apply a texture is UV mapping and so the HDR image is tilted 90° along the X axis, i.e. the sky is frontal and the ground is behind my shoulder... doh!

So, the only solution is to rotate this "semi" sphere to have the axes in the correct position, but you have to be careful to avoid the missing part of the sphere becomes part of the view; my english is not so good, so I hope you understood, otherwise I'll post some wireframe...

does anybody has a better solution for HRDI lightning with Rhino+Maxwell?

[bathsheba]

Hi,
So, the only solution is to rotate this "semi" sphere to have the axes in the correct position, but you have to be careful to avoid the missing part of the sphere becomes part of the view; my english is not so good, so I hope you understood, otherwise I'll post some wireframe... :roll:

does anybody has a better solution for HRDI lightning with Rhino+Maxwell?

I think you're doing it correctly, Rhino's poor mapping feature is very annoying. Hopefully you will only need to do this setup once, then you can reuse it.

-Sheba

[Micha]

Hi,

I build a sphere with the poles up and down - > got to the frontview -> draw a line horicontal and cut a tiny part of the down pole -> reverse normal -> ready to use.

[j_petrucci]

Hi,

I build a sphere with the poles up and down - > got to the frontview -> draw a line horicontal and cut a tiny part of the down pole -> reverse normal -> ready to use.

thanks Micha , your method is sure better than mine, even if I noticed that the HDRI is still 90° rotated, so the sphere needs however to be rotated, too; maybe MXI coordinates conversion to UV is inverted...



one little thing: developers can include ISO setting from the plugin?

[j_petrucci]

yes, I also think that could be an handy workaround...

[Micha]

hmmm ... I dosn't must rotate my env maps. And it is better for me, than my biased renderer use the env maps too.

Here a suggestion more: don't use the default rhino meshing for the MXI sphere. Better, manual build a mesh from it with less polygons and apply the emitter shader. I have got a speed increase of more than 30% in my last image.

[Micha]

... and here the easy way to flip normals: build a mesh from a sphere, so that less polygons will be used and flip the normal. It is inpossible to flip the normal of a sphere, but of a meshed sphere it works.

[Micha]

... oops, here a easy way for a NURBS spheres:

- draw sphere from the top view

- use command "MeshingManager" and set a polycount for rendering (small sphere are better to adjust, - scale it later to a big size keep the small poly count)

- now, the normal of the sphere can be fliped