View Full Version : clip maps

03-01-2003, 10:54 AM
I would really like to be able to asign more than one clip map per object. Based on uv texture maps.


03-01-2003, 12:55 PM
What do you mean? You already can layer textures for clipmaps just like normal textures. The only limitation is that the result will always be a 2 bit image with sharp edges but from a mathematical point it is very logical that it can be no other way.


03-02-2003, 07:23 AM
I'd like it if you can have them on a per-surface basis, because it happened to me that only parts of the object needed to have a clip map, and the other parts were not UV mapped, and then it happened that the whole rest is clipped although you want them to be unchanged :rolleyes:
Well you can then make a weightmap and an extra layer, but that's annoying.

Besides that it could then be saved with the object.

03-02-2003, 11:38 AM
I have used on clip map for this plam . It is all one layer and so once I load in layout asign a clip map I can clone it. The frons are very low poly, almost all the shape and such comes from a clip map. If I could add one or two more clip maps based on UV or surface then my precived geometry complexity could go through the roof while still only being a hand full of ploys.

03-02-2003, 11:30 PM
I see. Sounds useful sometimes even though right at the moment nothing obvious springs to my mind :rolleyes:.


03-04-2003, 11:21 PM
I am creating a lot of plant materials for Architectural renderings. It would be very usfull in creating low poly plants, that are one layer, easy to clone in layout, and have a lot of detail / variation.

very usfull for me.

I get a lot of milage out of one clip map for adding detail. having two or three would multiply it.

I am sure that it would have other maybe better uses. ;)

03-05-2003, 12:02 AM
Ok looks like I can do what I want to with assigning Transparency per surface based on an uv and texture map.

Sorry for all the fuss.

I think

Can anyone give me the break down on the where and the why a clip map should be used in rendering as apposed to transparency in texturing?

03-05-2003, 12:11 AM
A clip map will actually influence on how rays in your scene are being traced. Think of it as a pre-pass for deciding which objects to render. This means in areas where you clip out your objects the rays shoot right through until they hit the next visible poly. You should consider that even though clip maps produce results like transparency maps they are much more efficient. For a transparency map always more rays are needed because LW will always assume it needs to calculate refraction, specular etc. Also you will notice a difference when working with shadow maps - without a proper clip map e.g. a leaf mapped onto a square will produce a square shadow.


03-05-2003, 12:34 AM
No wait - Clip maps take no time to render!!!! and transparency takes forever - well almost forever.

So please give me - one of the two or both

Clip mapping in the Surface editor, and or more than one Clip map per object based on UVs!!!

CLIP MAP in surface editor!

03-05-2003, 01:35 AM
I'm not sure i understand your problem....
You can have multiple clip maps based on UV's... (only with UV's actually)

However, I'd also like to see clip maps stored in the object file...
rather than scene file.....

03-05-2003, 06:59 AM

Your right!

Ok my feature request changes once more please add a clip map feature to the surface editor so that it can be stored with the object file.

Clip maps are better than makeing something trasparent! Much Much faster render times!!!!

03-05-2003, 03:05 PM
Glad i could help Wade....
I thought i may be misunderstanding you....

But yeah i have yearned for object or surface based clip maps for a long time.... We can live in hope... :)

07-27-2003, 11:42 AM

Could one of you answer a question for me. I am using a clip map for an object used in a VT DVE I am building. I keep getting little sparkley effect on the clipped edge and some aliasing. I can't raise the Antialiasing above LOW or it won't load in VT. Since Clip Maps are 1 bit (B or W) I would prefer to use surface transparency to clip the edge softly but specularity and shadows are still apparent on the transparent parts. This object has heavy specularity (from two lights) and heavy shadow maps.

Any suggestions?



Examples Attached

07-27-2003, 04:05 PM
I think I got it. I applied the clip map on the specularity channel using blending mode 'Alpha'.