Fog plus height and noise #1313
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Please resolve conflicts. Probably easiest to |
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Do you think it is possible to directly use fogHeight to normalize the WS .y component, rather than fogRange ? It would be good to decouple vertical fog gradients from view direction fog gradients. |
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good suggestion, normalized fogHeight separately from fogRange. Its a bit less code and the result seems more visually predictable. Also updated the pen with these changes (codepen has a 1MB limit so I've only included x3dom.js, not x3dom-full.js) |
| * @var {x3dom.fields.SFFloat} fogHeight | ||
| * @memberof x3dom.nodeTypes.X3DFogNode | ||
| * @initvalue 0 | ||
| * @range [0, -inf] |
| * @instance | ||
| * Hint: Start with a low visibilityRange (very dense fog) to adjust fogHeight. | ||
| */ | ||
| this.addField_SFFloat( ctx, "fogHeight", 1000000.0 ); |
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Should the default value be 0 ?
The pen looks good. Did you want to incorporate these changes in the PR as well, eg. commit them to the branch ? |
| " if (fogHeight == 0.0) {\n" + | ||
| " color.rgb = mix( fcol, color.rgb, f0 );\n" + | ||
| " } else if (fogHeight > 0.0) {\n" + | ||
| " float f1 = clamp( 1.0 - ((abs(fogHeight)-fragPositionWS.y) / abs(fogHeight)), 0.0, 1.0);\n" + |
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abs(fogHeight) here always fogHeight since positive. So use just fogHeight
| " float f1 = clamp( 1.0 - ((abs(fogHeight)-fragPositionWS.y) / abs(fogHeight)), 0.0, 1.0);\n" + | ||
| " color.rgb = mix( fcol, color.rgb, max(f1,f0) );\n" + | ||
| " } else if (fogHeight < 0.0) {\n" + | ||
| " float f1 = clamp( ((abs(fogHeight)-fragPositionWS.y) / abs(fogHeight)), 0.0, 1.0);\n" + |
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Since fogHeight negative, this is:
(-fogHeight-fragPositionWS.y)/-fogHeight = (fogHeight+fragPositionWS,y)/fogHeight
simplified.
May need more thinking.
| " float f1 = clamp( ((abs(fogHeight)-fragPositionWS.y) / abs(fogHeight)), 0.0, 1.0);\n" + | ||
| // de-couple fogHeight from fogRange | ||
| //" color.rgb = mix( fcol, color.rgb, max(f1,f0) );\n" + | ||
| " color.rgb = mix( fcol, color.rgb, min(f1,f0*2.0) );\n" + |
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f0*2.0 ? May need clear thinking.
| " } else if (fogHeight > 0.0) {\n" + | ||
| " float f1 = clamp( 1.0 - ((abs(fogHeight)-fragPositionWS.y) / abs(fogHeight)), 0.0, 1.0);\n" + | ||
| " color.rgb = mix( fcol, color.rgb, max(f1,f0) );\n" + | ||
| " } else if (fogHeight < 0.0) {\n" + |
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just else
The remaining if (..) is not necessary. In the shader code branching logic should be avoided as much as possible since it is considered slow.
Optional fogHeight and fogNoise. Not setting them will maintain the original fog behavior. The height is best seen when lowering the visibility range. here is a working pen. https://codepen.io/mrmernan/pen/KKbYrdJ