spherically re project a hdri on to geometry

V-Ray V-Ray Common Render Theory
1

ok ok

i want to spherically re project a hdri on to geometry like …
the real viz thing but i want to do it in max…

and max’s sphere uvw mapping is in ward i want out word…projection …

and the Olney way i can think is a pain in the ass…multiple camera re projection thing…
so …am i missing something?

http://imagemodeler.realviz.com/photomodeling-software-products/vtour/modeling-software.php

2

So you want to project an image onto geometry? Just start texturing the geometry with the desired portions of the image. Use UVW tools to unwrap or texture bake, etc…

Not sure how the spherical UVW is inward and not outward? That doesn’t make any sense…

3

Indeed. The only possible difference i could imagine for Spherical UVs would be flipping on the u-axis

Regards,
Thorsten

4

I guess you are talking about a “mirrored Ball” HDRI ? In this case you could use HDR Shop
to convert it. Open your HDR in HDR Shop. Choose
/Image/Panorama/Panoramic Transformation/.
Select “Mirrored Ball” as source image and “Latitude/Longitude” as Destination Image. This
creates an image that can be mappen spherical.

cheers,

sam

5

its not a mirror ball is cylinder mapped hdri…

hmm …
its not a mirror ball is cylinder mapped hdri…

there should be a way to …do a 360 camera projection …with out doing multiple camera projection…

6

I still dont get what is wrong with cylindrical or spherical mapping. can you show a pic of the problem ?

Regards,
Thorsten

7

Okay, you should have mentioned that before. You have a Cylindrically mapped panorama that you need to convert to a Spherical panorama? In that case convert it in HDR shop.

8

i have done something similar in the past and you have to think about two problems:

Say it’s a square and you have an hdri panorama from in the middle of if and want to use it to project this panorama onto a 3d model of this square.
You have a material with the hdri as diffuse map and apply it to the mesh of the 3d reconstruction of the buildings. Then you have to apply an UVW-map (spherical, or in your case cylindrical) to the 3d object and place the gizmo to the geographical correct position where you stand when you make your panorama.

ok, here the two problems:
1. there will be not enough verteces on your mesh to get an undistorted map, so you have to subdivide you mesh

2. there will be “Projectionshadows” because this mapping can’t look around the corner… you would need another map for these artifacts

… and these are the reason why it’s easier to work with cameramapping and realviz.

:-/