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View Full Version : Mapping image on object, newbie question


MJV
11-22-2004, 05:05 AM
Ok, stupid newbie question, but I'd really like to get past this little roadblock so hopefully someone will help. I read the manual and it seems like getting an image mapped on an object should be pretty straightforward, yet I can't do it. Default scene, default geometry sphere, blin surface shader, image in diffuse channel. Seems like I should see the nolcon_pic image now mapped on my sphere, but instead it just turns pink. Any ideas?

http://www.mvpny.com/XSIImageShadingMV.jpg

ndog
11-22-2004, 06:26 AM
Have you set the texture projection?

Ablefish
11-22-2004, 07:06 AM
Yeah, Get->Property->Texture Projection->[projection type]. Or there's a short cut to the exact same command if you scroll down in the image node property page.

MJV
11-22-2004, 12:33 PM
Yeah, Get->Property->Texture Projection->[projection type]. Or there's a short cut to the exact same command if you scroll down in the image node property page.
Thank you very much. Stupid newbie hurdle surpassed. :bounce: I thought I tried everything there including the new button, but tried it again and it worked. Also, I guess I was thinking that with everything default, it might just load with a default projectoin already in the ballpark.

MJV
11-22-2004, 01:08 PM
Oops sorry, new question. Any idea what's going on with this spherical projection at the top? Seems to kind of fall apart there.

http://www.mvpny.com/XSIImageShading2MV.jpg

Ablefish
11-22-2004, 04:06 PM
Yeah, you can open up the texture editor to look at the default spherical uv set to understand why it's looking like that.

One way to improve this is by changing the texture projection from Explicit to Implicit. You can do this by selecting your sphere and pressing Alt-Enter. Now find the Texture_Projection_Def tab. One thing though - after doing this, the projection is dependant on the support object - in other words you can't freeze the UVs in this case.

You can still freeze your construction stack on the object, but you have to open up an explorer and an op in the stack before hitting the freeze button - otherwise your projections will be frozen and their supports will vanish.

MJV
11-24-2004, 12:09 PM
Yeah, you can open up the texture editor to look at the default spherical uv set to understand why it's looking like that.

One way to improve this is by changing the texture projection from Explicit to Implicit. You can do this by selecting your sphere and pressing Alt-Enter. Now find the Texture_Projection_Def tab. One thing though - after doing this, the projection is dependant on the support object - in other words you can't freeze the UVs in this case.

You can still freeze your construction stack on the object, but you have to open up an explorer and an op in the stack before hitting the freeze button - otherwise your projections will be frozen and their supports will vanish.
Thanks. Opened the texture editor as you suggested and I can't understand why the default spherical uv set is so messed up. Changing the projection to Implicit makes the image render correctly, but the UV's as shown in the texture editor are unchanged. Why must they come to a point like that on the top and bottom?

Default sphere with default spherical projection with default image should render correctly. It's almost incomprehensible that it does not.

4SweetB
12-25-2004, 06:56 PM
Default sphere with default spherical projection with default image should render correctly. It's almost incomprehensible that it does not.

I totally agree. I tried this in LightWave. I took the default image from XSI and asked LightWave to make a sphere. LightWave doesn't even HAVE implicit mapping, as far as I know, anyway. None of that distortion! (I'm not saying LW is better than XSI... I like XSI better in most respects, but LW happens to handle this better.)

You can tell the reason by comparing the UV maps generated in XSI and in LW. In XSI, the poles come to only four samples at the corner points of the UV map. Not so in LW... the vertex for each pole has a separate sample for each of the divisions.. so the top in the UV map zig-zags. This keeps everything straight instead of having that swirly nonsense.

But LW doesn't have NURBS, or an operator stack.... seems like you can never win, lol.

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