Jump to content
Sign in to follow this  
sant0s81

earth texture on sphere, subdivide specific areas to add higher res texture

Recommended Posts

Hello,

I dont know if thats the best titel, but I try to explain what I would like to get.

I have a sphere with a high resolution earth texture.
It looks great in far and medium distance.
Now there is a specific area where I have to go even closer - and than again closer.

The problem is, that the overall texture is already extrem big.
So I again use a very high resolution texture, but only from that specific area.
As closer I come, I only chose that area that I need and get a very high resolution.

In Softimage my workflow was with clusters.
I divided a GRID (not a sphere) in 8*8 tiles and projected the massive overall texture.
Than I chose the face of that area and projected a texture only on that face (and a Cluster), but again with a very high resolution.
For getting even closer, I divided only one face in 4 faces and could again chose only one face, to project the part of that area in high resolution.
Finaly I used a FOLD operator, to create a sphere from that grid.

 

I add a picture, to explain it better.
Every color has its own projection.
The green one is just a spherical projection - but the other colors are all planar.

How would I do something like that in Houdini?

Thx alot :)

globe_tiles.thumb.jpg.790432b1e46356d273a555c0aa3ae982.jpg

 

 

 

Share this post


Link to post
Share on other sites

Hi Salomon,

if it's just about switching textures, you better solve this within a shader. Based on the distance from camera to surface you could smoothly blend between a large texture (ie. earth) and a tileable close-up texture (ie. mars).

image.png.b3d32dfd07cd8b420ec39abe17accc17.png

 

blend_texture.hipnc

Share this post


Link to post
Share on other sites

@konstantin magnus

thx for your reply.

Thats something i definitly need, too - the fading.

But its not about tileable textures but this:

I have one texture that covers the earth - its 40k.
Than I zoom in and have only one face covered with a texture (lets say europe), also 40k.
Than I divide that face into 4 faces and use only one face, to again add an 40k texture (lets say germany).
And finaly, I divide that face where germany is projected, again in 4 faces and add a texture, on with the alps - 40k :D

If I would cover the sphere with one texture that has the resolution of that little face, I need a texture beyond the possibilities what Houdini could handle.

Ill create an example to be more specific.

 

Share this post


Link to post
Share on other sites

Just use 4 texture nodes then and blend between those. The tileablity was just to illustrate that

  • more close-up maps are possible by scaling the UVs inside a material and
  • that you won't need any subdivision faces to achieve the effect.

Share this post


Link to post
Share on other sites

At some point, you are at the compositing level. Just create Houdini footage for the first zoom in. Once you are no longer looking at a sphere, use the 40k images to fake the rest in your compositor. Check out the old earth zoom tutorial on VideoCopilot.

Share this post


Link to post
Share on other sites

@konstantin magnus and @Atom

Thx again for answering.

Of course I am rendreing these different parts in seperate passes and than blend it in comp.

But its about the absolut correct position of the different textures.
Its not that I have just a global texture, than some part of closer europe and even closer germany map.

They always fit absolut correct in one of these rasters.

Every next level is a new datasaet downloaded with a higher zoom, but always on the absolut correct position of one of these smaller rasters.

Actually its like the system google maps is using.
Each zoom level has always a raster of maps, each raster has 256*256px (or 512px, dont remember).
When you zoom in, you still have the same resolution, just reloaded with a higher zoom.

I just wonder, how I can create UVs, that stick exactly on a face only, not on the hole geometry.

I attach a picture of a grid to explain a bit.

@Konstantin: The problem with scaling the UV is, that I cannot use the same UV, since the textures are on complete different positions on the sphere/grid.
 

globe_tiles2.thumb.jpg.4825d757ce13c74b821966e998ef9313.jpg


 

 

Share this post


Link to post
Share on other sites
2 hours ago, sant0s81 said:

Every next level is a new datasaet downloaded with a higher zoom, but always on the absolut correct position of one of these smaller rasters.

@Konstantin: The problem with scaling the UV is, that I cannot use the same UV, since the textures are on complete different positions on the sphere/grid.

Then scale and translate the UV coordinates inside the material using the UV transform-node.

 

Share this post


Link to post
Share on other sites

As Konstantin say it can be done with uv scaling, but I have done exactly the same earth setup stuff, first in 3dsmax, then in C4D, and it's more easy to do with multiple uv sets.
Each tile covering the full uv domain of the corresponding faces. With faces maching the google or Nasa slicing.
Thus I guess your question is more how about multiple UV sets in houdini.

If this help, here is a little start exemple.
If you use mantra for rendering, you must unlock the principledshader to change the second (or third or...) uv name inside.
second texture don't show in viewport but is rendered.
This shading part could surely be improved, as i'm not a mantra user.

Multiple uvs.hipnc

Share this post


Link to post
Share on other sites

I just realised, that I have to start with uv, than uv2, uv3, etc - NOT with uv, uv1, uv2, etc...
Did cost me some hair on my head :D

But I am facing another problem now and I dont understand it.
When I subdivide AFTER everything else, the textures suddenly get totaly messed.
Is there a way, to subdivide, but keep the textures correct?

Of course I see that the IDs are changed - but I thought, since I do that AFTER everything else, it should still stay intact...

edit: strange is, that the first texture is okay, just the other 4 are kinda distored...

edit2: solved - just had to change Algorithm, now it works.

 

subs_destroy_texture.thumb.jpg.077d0b58a8c011714cadc31bdcb7f3e8.jpg

Edited by sant0s81

Share this post


Link to post
Share on other sites

Hey :)

I am having a new problem with my little project.

Everything runs so far and its fun.
But I get seams between the different textures.

When I connect the tiles in photoshop, there is no seam.
I tried playing with the UV Transform, but the seams stay.

Do I somehow have to increase the resolution of the UVs?

seams.jpg.e57826cbbc87c337db3caa7301adfdb4.jpg

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×