View Full Version : Clip Maps

11-13-2006, 09:57 AM
Maybe a stupid question but a question all the same. I regularly use clip maps on 2d trees and people and have found that if you use a 256 color grey map to soften the edges it still reacts like a black and white clip map. (i.e. no soft edges). If I apply the clip map to the transparency channel of the object I get the soft edge but also get a faint outline of the rectangualr clip map and even more so when you use some specularity on the object.

So my question is can you use clip maps and get a soft outline edge on your objects OR can you use the clip map on the transparency channel and not get the faint rectangular outline.

Thanks in advance

11-13-2006, 02:39 PM
Hey there.

The short answer to your question is, YES you must use an image map for the specularity channel with 'Black' where you need no specular and therefore no actual poly edge.

I didn't have a chance to try this before this post but as I recall you can use a clip map with a shadow mapped Spot light, but NOT with transparency mapped polys as the shadow will reveal the actual polys with just the transparency map.

Now I wonder if you can shadow map with both the clip & transparency. Hmmm...


Your tag suggests north of 60? Just curious.

11-13-2006, 03:59 PM
dear wavers

although it is not directly related with this question but since we are talking about ClipMaps ..why dont we have SURFACE based clipmaps. I mean what is preventing it in SDK...Even as a shader it would be great thing.Because Adjusting Clipmaps in Layout just a time consuming process...


11-13-2006, 04:27 PM
Never mind.

11-13-2006, 04:51 PM
Clip maps can only use black and white info. If you have an 8 bit greyscale it will still clip that way. If you want to reduce jaggies at the edges use a higher rez clip map and a transparency map. If you dont want the specularity to show up on the transparent parts then use the clip or transparency map as an alpha in the spec channel.

11-13-2006, 07:08 PM
Thanks for the replies. I will try the clip map on the Specularity channel. If it works then I don't have to load a clip map every time I load a 2d tree or person. It will save a lot of time over the long run, plus The info gets saved with the object (BONUS!!!!!!!!)

11-13-2006, 07:17 PM
Use a greyscale image on the spec channel. Black where you dont want any spec and grayscale values where you want varying degrees of it.