View Full Version : Urgent!!! FPrime/Clipmap help!

03-22-2004, 08:38 PM
Hi there! Really ned to solve this fast! The background color shows through the clipmas of my trees. I havenīt nailed it down and donīt have the time right now...

Anyone? Please???


03-22-2004, 08:38 PM
And a pic! Same happens with Transparency as Surface. Strangely when i turn on "Unseen by Rays" the problem dissappears, but i need the reflectionn of the foliage in the windows...ARRRGHHHH...4 hours to finish this!!!

03-22-2004, 09:03 PM
As I don't have Fprime, I can't be of much assistance, but I did find this in the manual:

I changed my clip map parameters, or an image brightness, or an Imageworld seam angle. FPrime didn't refresh, but now I'm seeing strange ghosts in FPrime's render.

LightWave announces most changes to its scenes to plugins, so FPrime is able to recognize that it needs to restart its render to show the new effect. But LightWave doesn't report some changes like clip map textures or ImageWorld settings. In these cases, you can just press the FPrime "Refesh" button manually.

03-22-2004, 09:38 PM
Nope, thatīs not the problem, unfortunately. Thx!

Anyone else had this?

03-22-2004, 10:20 PM
If all else fails you might try using you clip as a tranparency map and hope that FPrime doesn't bog down on it like LW does. I only say this if you can't get it working in time...

I read somewhere that an image world background or something might effect it?...


If you feel up to it post your scene and see what others find. I might be willing to try...

03-22-2004, 10:24 PM
Does it do this in the LW render? If not then I would say that it may be a bug with F-prime. Sorry not much help. :( Also check all your alpha settings in the properties panel and the surface editor to make sure everything is all right there. Of course if LW's render looks fine then you may have to just optimize your scene and render away with the good old renderer.

P.S. Check and make sure that you placed the clip map on the right object. I have put it on the wrong one before and took me a while to figure out what was going on. Just a thought. Hope you get it figured out.

03-22-2004, 10:30 PM
Maybe scrub forward a few frames and then back to 0? :confused:

03-22-2004, 10:33 PM
Does this happen when you use the FPrime renderer? The interactive window uses a simpler alpha.

03-22-2004, 11:03 PM
Good point there CoryC. I have noticed problems with it as well. Could be the fix.

03-23-2004, 12:45 AM
Hi CB_3D,

I did some testing, and I have the "problem" too. I fixed it by simple increasing the ray recursion limit in the render options dialog. I hope that fixes it for you too.

Have fun,


03-23-2004, 01:56 AM
yep ray recursions here as well, but that doesn't completely solve the problem... there still some areas I have problems where clips are not fully removed, I suspect it may be down to file formats. So if you still have probs, you could try playing with the formats aswell.

Just for the record, I am using 32bit png, instanced in LW with the instance changed to alpha and projected as the clip - this does not work with FPrime as it does with LW.

03-23-2004, 01:58 AM
SIGH! Happens in the Render, and happens with recursion of 16, too.. Ohhh man.

03-23-2004, 02:04 AM
I feel for you, I had two hours sleep Sun night getting a render for the boss on Monday morning - which he still hasn't looked at!

Just throwing other ideas here in case youve missed anything...

first off Quit everything and reload (I have had some strange things seem to happen - even to the LW renderer lately) then double check alll the settings you thought you had

Ray trace transparancies on?
Double sided polys?
got rid of all n-gons?

03-23-2004, 02:08 AM
oh, have you changed it from a clip map to a Transparancy channell?

then you might need to change the Refraction options from Backdrop Only to Ray Trace?

03-23-2004, 08:10 AM
Read somewhere that FPrime can't deal with clip maps yet. So don't even try. Render out in Lightwave.

03-23-2004, 08:29 AM
Your not the only one having problems. I loaded up a scene in which I had used clip maps on trees and used the FPrime renderer and it seems to have partial problems with clip maps. Anyone else having the same problem?

03-23-2004, 08:44 AM
I had the same problem... I could either make the polygon single facing (which didn't look right for my trees), or bump up the recursion to 16. I was running at 8 but if I bumped it to 16 it'd clear up the problem.

03-23-2004, 09:14 AM
Originally posted by tapsnap
Read somewhere that FPrime can't deal with clip maps yet. So don't even try. Render out in Lightwave.

I only have FPrime since friday, and I can say already for me going back to the LW renderer is an absolute last resort, better to optimise your models and surfaces for FPrime than wait for an LW Render.

03-23-2004, 09:22 AM
Try using a jpg image for your clipmaps(no alpha) also make sure that "texture antialiasing" and pixel blending are unchecked(off) in your clipmap surface editor...

03-23-2004, 11:49 AM
Suggestion #1003:

I thought clip maps only needed to be 1-bit black and white? I've used hi-rez bmps and gifs for clip maps and they've worked. In fact if you use a higher bit depth LW will just have to convert your gray scale maps into black and white. Go with the lowest depth you can. If you need gray scale then you should use trancparency settings instead.


As it's been said- no N gons.

Here is a very ugly image I made up...mabye I'm not doing something to get thigs wrong? These are using 1-bit clip maps and the texture is double sided. MC radiosity, Background, and just plain raytrace made no diffrence in the clip map results though. It is an FPrime viewer window image- not a render. I used a partical emmiter to generate 300 or so particals. Image world being turned on or off made no diffrence as well in my tests...

Maybe you have to apply the FPrime plug to each clipped poly?

#1005- just comp them in with your FPrime render. Use LW for the trees and such and then port them over in PhotoShop, PSP, DF or what ever.

03-23-2004, 01:31 PM
I just did a test with some x frog trees. Trunk in one layer and leaves in a seperate layer parented together. UV texture for leaves and an instance copy of the png leaves set to alpha only used in transparency channel. Works fine in F Prime. Didn't try the Clip map.

03-23-2004, 01:36 PM
The car crash scene included in the LW content directory has the same problem, the trees look weird and the road has the same blue like color bleeding through.

I would suggest rendering the trees in LW then Comping. But I guess your 4 hours have all ready passed by now.

03-23-2004, 02:56 PM
Originally posted by WizCraker
The car crash scene included in the LW content directory has the same problem, the trees look weird and the road has the same blue like color bleeding through.

I would suggest rendering the trees in LW then Comping. But I guess your 4 hours have all ready passed by now.

The missing areas are caused by N-Gons. I went in to the model and trippled the N-gons and woosh! No more missing roadway!

Ditto for the trees too. But there aren't any clip maps here...just transparency. I didn't notice a diffrence between them in the FPrime OR LW render.

03-23-2004, 03:08 PM
OT: BTW the crash scene looks best if you turn the lights down, add MC 5 bounces, and let Fprime cook. It's an FPrime horror scene with evil N GONS.

03-23-2004, 03:19 PM
Evil N-Gons I like that.

03-23-2004, 04:20 PM
Hey I like that lighting there wacom.

What happened CB_3D??? Hope everything worked out OK. :(

03-24-2004, 07:45 AM
Hi there. I finished the work by retouching the bad areas in Photoshop. Looks good, but itīs an NDA job, so i canīt post finals.

Funny thing is, i prepared the tree and the clipmap with FPrime in a separate scene without problems. Only when imported into the final scene the trouble began. I substituted the foliage object (many intersecting spehres like the Dave Jerrard trees) with one simple big sphere and the veins clipmap caused no problem.

So far i can only suspect that a big number of intersecting geometry confuses FPrime.

This weekend i will try to nail the combination down that produced the problem and then send a samplescene to Worley labs.

Thx for all the input

03-24-2004, 07:50 AM
Hi CB_3D,
I just had a similar problem... Is the geometry behind you tree "Unseen by Rays" ?
FPrime seems to treat clipmaps as transparent polygons, which are always raytraced.
Your shadow seems to be o.k., so I guess it is not the object, but the geometry behind it.
Mike - who's finding his way around FPrime at the moment too - Great Schtuff(tm) ! :p

03-24-2004, 02:37 PM
Nope, the house object behind has no problems at all. I even tripled the whole thing just to make sure.

Could be the differences in bounding box size, too.

03-24-2004, 03:16 PM
Have you tried a simple clipmaped polygon next to the tree?


03-24-2004, 05:48 PM
Nailed it down, i think.

It has to do with the ray recursion limit, indeed. Bump it up to 24 and 12 intersecting planes (in one layer) with a procedural clipmap will render fine. 13 will show the background. Itīs something like that, i didnīt actually test it by strict numbers.

A pitty if this is a limitation to keep it fast, i really liked to use clipped foliage spheres.

03-24-2004, 06:24 PM
Ray recursion 2

03-24-2004, 06:25 PM

03-24-2004, 06:34 PM

Please post the scene, object files, and clip maps as a zip so that we can toy around with your findings. PLEEEEaSE.

03-24-2004, 06:47 PM
There ya go.

03-24-2004, 07:36 PM
Yeap. I had the same problem. Increasing the RayRecursion reduces the problem but doesnt solve it.

Shoot with LW, till we have this fixed.


03-24-2004, 11:20 PM
It seems, and it would makes sense, that double sided textures, when used with a clip map or tranparency map, take almost twice as many RayRecursions to get them looking right. It did seem too that the deeper the nesting of polys in the object the more rays it took to get through the object without problems.

For instance the little "buildings" in your test setup- the problem goes away from left to right almost predictably as you up the rays.

In addition it seems that it doesn't mater if the polygons intersect or not. If they visually overlap with a clip map on each or a transparency map, the background will show through. The more they over lap visually the more rays it takes. When you make them double sided it almost takes twice as many rays. Seperating the objects into diffrent layers seems to make little diffrence as well.

03-29-2004, 07:44 PM
And it happens with regular transparency, too.This is a huge dissapointment for me.

In practice this means FPrime cannot be used when there are more than 12 glas polys overlapping.

I do mainly architectural stuff and use a lot of transparencies in my previsualisations...

Already sent in a bugreport, but havenīt got an answer so far. I really really hope this is "only" an oversight to be removed inthe next version.

For its preview only (which is awesome) i wouldnīt have spent that amount of money, and this limitation/bug makes the renderer broken, IMHO.

Sorry, just venting off. After mailing in the bugreport a few days ago i sort of was hoping to read something about it in FPrimeīs FAQ.

Iīm sure it will get sorted out.

03-29-2004, 09:37 PM
Knowing Worley, I would bet that he will figure it out soon. :)

03-30-2004, 06:25 PM
sent the same bugreport to worley, and got an answer from steve hisself! generically as follows: you guys are absolutely right about the ray recursion aspect, but steve recognizes this clipmap issue specifically as a limitation of fprime, to be fixed with v. 1.02. as he noted, architects can do hundreds/thousands of billboard trees :D in one scene

03-30-2004, 07:24 PM
Ok, got apersonal answer, too, with FPrime 1.02 attached :-)

Will take it to the dongle at the company tomorrow and test it out. Changes from 1.01 look promising, but i wonīt post the list here before they release it publically.

Cool customer support, that!

03-30-2004, 07:38 PM
What did I tell you.... :D Steve Worley is the best!!!!

03-31-2004, 05:09 AM
ok, the clip problem has been eliminated, now the same has to be done for transparency, which i already mailed in. if they continue to react so fast weīll have a rocksolid app in no time :-)

BTW, could an administrator move this to the third party forum, please? thx!