On 12/6/2016 11:55 PM, clipka wrote:
> Am 06.12.2016 um 08:05 schrieb Mike Horvath:
>> I am having trouble rendering the attached scene without artifacts and
>> gaps in the isosurface. I already increased the scale of the scene by
>> 200 and the max_gradient of the isosurface to 100. Anyone have any tips?
>
> You seem to be running into /some/ kind of problem when the RGB values
> get excessively low.
>
> Clipping the C parameter of the fD function to some near-zero negative
> value seems to do the trick:
>
>     #declare fClip = function(X,A) {select(X-A,A,X)}
>     #declare fD = function(C) {abs(fClip(C,-0.1)-0.5)-0.5}
>
> This lets you get away with a max_gradient of 20.
>
> (You still have a coincident surfaces problem between the isosurface and
> the box, but I guess you can figure that one out yourself.)
>

I changed the camera angle and the problem reappeared.

camera
{
//	#local cam_distance	= 40;	// render at 8192x8192
//	#local cam_planesize	= 4;	// render at 8192x8192
	#local cam_distance	= 17;
	#local cam_planesize	= 1.7;
//	#local cam_distance	= 20;	// render at 4096x4096
//	#local cam_planesize	= 2;	// render at 4096x4096
	#local cam_aspectratio	= image_width/image_height;
//	orthographic
	location	-z * cam_distance
	direction	+z * cam_distance
	right		+x * cam_planesize*cam_aspectratio
	up		+y * cam_planesize
	rotate		+x * asind(tand(30))
//	rotate		+x * 90
	rotate		-y * 045
//	rotate		+y * 180
	rotate		+y * RotateAmount
	translate	1/2
	scale		ScaleAmount
}

max_gradient is set to 200, and I am using your revised fD function.

Mike

Post a reply to this message